phenomenon · claim-type · cross-domain-transfer · mechanism · claim-relation · replication-status · limitation — grounded in the full text| phenomenon | entorhinal alvear pathway input to hippocampal CA1— “The entorhinal cortex alvear pathway is a major excitatory input to hippocampal CA1, yet nothing is known about its physiological impact.” | |
| claim-type | mechanism— “Therefore, our data suggest that the alvear pathway primarily affects hippocampal CA1 function through feedforward inhibition of select interneuron subtypes.” | |
| method — evidence | — “We investigated the alvear pathway projection and innervation of neurons in CA1 using optogenetics and whole cell patch clamp methods in transgenic mouse brain slices.” | |
| object of study — evidence | — “The entorhinal cortex alvear pathway is a major excitatory input to hippocampal CA1, yet nothing is known about its physiological impact. We investigated the alvear pathway projection and innervation of neurons in CA1 using optogenetics and whole cell patch clamp methods in transgenic mouse brain slices. Using this approach, we show that the… | |
| research question — evidence | — “Although the alvear pathway ultimately terminates in the SLM, alvear pathway axons in the SO have synaptic boutons that are thought to form excitatory synaptic connections with CA1 PC and interneuron dendrites ( Deller et al . 1996 ). However, the physiological impact of the synapses in the SO has not been investigated.” | |
| contribution — evidence | — “Optogenetic theta burst stimulation was unable to elicit suprathreshold activation of CA1 PCs but was capable of activating CA1 interneurons. However, different subtypes of interneurons were not equally affected. Higher burst action potential frequencies were observed in parvalbumin-expressing interneurons relative to… | |
| transfer | from optogenetics: a channel expressed in one projection population, which is what makes a single pathway separable from the three that share its target layer— “To explore this, we expressed the optogenetic excitatory channel oChIEF ( Lin et al. 2009 ) in layers 2 and 3 (L2 and L3) of medial entorhinal cortex (MEC) to study the impact of these inputs onto PCs and interneurons with cell bodies located in the SO of hippocampal CA1. The MEC was chosen as the viral expression target by virtue of the… | transfers[0] |
| transfer | from mouse genetics: the driver lines that decide which region can be targeted - and here, which region was studied— “To explore this, we expressed the optogenetic excitatory channel oChIEF ( Lin et al. 2009 ) in layers 2 and 3 (L2 and L3) of medial entorhinal cortex (MEC) to study the impact of these inputs onto PCs and interneurons with cell bodies located in the SO of hippocampal CA1. The MEC was chosen as the viral expression target by virtue of the… | transfers[1] |
| transfer | from neuropathology: the reported distribution of tau across the two pathways, used to argue the studied one matters clinically— “In addition to being important for normal brain function, the EC is one of the first regions in the brain to display neurodegeneration and dysfunction in Alzheimer’s disease (AD) ( Braak and Del Trecidi 2015 ). The initial pathology associated with AD is hallmarked by an accumulation of hyperphosphorylated tau protein that misfolds and… | transfers[2] |
| transfer | from oscillation research: theta burst stimulation as the physiological input pattern, rather than single shocks— “Although the timing of action potentials in individual MEC L3 projection neurons do not correlate well with population EC theta field potentials, MEC L3 projection neurons do fire coherently with their own internal theta activity” | transfers[3] |
| mechanism | Glutamatergic alvear terminals in stratum oriens excite local interneurons, which in turn hyperpolarize CA1 pyramidal cells through GABA-A receptors, so the net effect of the pathway on pyramidal cells is inhibition rather than excitation— “Interneurons excited by alvear inputs then inhibit postsynaptic CA1 PCs via the activation of GABA A receptors.” | mechanisms[0] |
| mechanism | Rhythmic burst firing of alvear-driven PV perisomatic interneurons imposes rhythmic perisomatic inhibition on pyramidal cells, which the authors propose as a contribution to theta rhythm generation— “our data suggest that alvear excitation of PV interneurons in hippocampal CA1 may contribute to theta rhythm generation by perisomatic interneurons” | mechanisms[1] |
| mechanism | the excitatory input onto pyramidal cells is monosynaptic but too weak to reach threshold even under theta burst stimulation— “Our results suggest that alvear inputs from the MEC were capable of producing facilitating low probability release glutamatergic synapses onto both PCs and interneurons in the SO of hippocampal CA1. The alvear inputs onto the basal dendrites of CA1 PCs produced subthreshold EPSPs even under robust theta burst stimulation paradigms. In… | mechanisms[2] |
| mechanism | while the same input drives interneurons to fire, and the inhibition arriving at PC is therefore disynaptic— “In contrast, TTX completely inhibited MEC alvear input mediated IPSCs in CA1 PCs. Importantly, 4-AP could not rescue the IPSCs inhibited by TTX in CA1 PCs. These results suggest that inhibitory synaptic transmission driven by MEC alvear input stimulation was not monosynaptic. Furthermore, the IPSCs in CA1 PCs were blocked by both AMPA… | mechanisms[3] |
| mechanism | with parvalbumin cells doing more than half of it, shown by silencing them during the stimulation— “PV interneurons play a crucial role in coordinating biologically relevant rhythms in populations of hippocampal principal cells ( Buzsaki and Wang 2012 ). These rhythms include gamma and theta rhythms. Our observations that alvear theta burst stimulation produced rhythmic IPSCs in CA1 PCs is consistent with previous observations. Moreover, we… | mechanisms[4] |
| mechanism | and both sets of synapses facilitating, which marks them as low release probability— “In contrast to the alvear pathway, the EC TA pathway synapses on the distal apical dendrites of CA1 PCs in the SLM ( Steward 1976 ; Steward and Scoville 1976 ). There is some disagreement on whether stimulation of the EC in vivo is capable of eliciting suprathreshold excitation of CA1 PCs ( Andersen et al . 1966 ; Segal 1972 ; Yeckel and… | mechanisms[5] |
| extends | Milstein et al. (2015)— “Therefore, unlike the perforant path ( Milstein et al . 2015 ), 5 Hz theta burst activation of the entorhinal cortical alvear pathway was capable of activating both perisomatic and bistratified PV interneurons in hippocampal CA1.” | claim_relations[0] |
| extends | Milstein et al. (2015)— “A significant proportion of the interneurons activated by the alvear pathway were parvalbumin (PV)-expressing perisomatic interneurons that have been previously reported to have limited responses to TA pathway stimulation ( Milstein et al . 2015 ).” | claim_relations[1] |
| supports | feedforward inhibition as the principal effect of entorhinal input on CA1 pyramidal cells— “In conclusion, our study demonstrated that the alvear pathway from the MEC innervated both CA1 PCs and interneurons. These glutamatergic excitatory inputs were weak and incapable of activating CA1 PCs but were capable of eliciting action potentials in interneurons. However, not all interneurons were equally affected. PV-expressing… | claim_relations[2] |
| contradicts | the assumption that the two entorhinal pathways engage the same interneuron population— “Notably, PV interneurons have been demonstrated to produce little to no response to SLM stimulation ( Milstein et al . 2015 ). Therefore, alvear pathway terminals in the SO appear to be capable of activating different subsets of interneurons relative to TA inputs.” | claim_relations[3] |
| reconciles | the disagreement about whether entorhinal stimulation drives CA1 pyramidal cells, by noting the in vitro literature is consistent where the in vivo one is not— “This is in spite of the extensive knowledge of the effect of in vivo EC stimulation on the excitability of hippocampal CA1. Some groups have observed a monosynaptic suprathreshold activation of CA1 PCs following electrical stimulation of the EC in vivo ( Segal 1972 ; Yeckel and Berger 1990 , 1995 ), whereas other groups observed only… | claim_relations[4] |
| critiques | earlier comparisons of the two pathways' strengths, which stimulated a site that activates three inputs at once— “These data may seem to suggest that the TA pathway input is stronger than the alvear pathway in producing responses in hippocampal CA1 PCs. However, stimulation in the SLM ( Takahashi and Magee 2009 ) would activate more than just TA synaptic terminals. SLM stimulation potentially activates alvear inputs that ultimately project to the SLM (… | claim_relations[5] |
| predicts | that this pathway contributes to theta rhythm generation through perisomatic interneurons— “PV interneurons play a crucial role in coordinating biologically relevant rhythms in populations of hippocampal principal cells ( Buzsaki and Wang 2012 ). These rhythms include gamma and theta rhythms. Our observations that alvear theta burst stimulation produced rhythmic IPSCs in CA1 PCs is consistent with previous observations. Moreover, we… | claim_relations[6] |
| supports | the early vulnerability of this specific input in Alzheimer's disease, from the reported tau distribution— “In addition to being important for normal brain function, the EC is one of the first regions in the brain to display neurodegeneration and dysfunction in Alzheimer’s disease (AD) ( Braak and Del Trecidi 2015 ). The initial pathology associated with AD is hallmarked by an accumulation of hyperphosphorylated tau protein that misfolds and… | claim_relations[7] |
| sense | A MAJOR INPUT PATHWAY WITH NO PHYSIOLOGY ATTACHED TO IT: the alvear pathway is a MAJOR EXCITATORY INPUT to hippocampal CA1, YET NOTHING IS KNOWN ABOUT ITS PHYSIOLOGICAL IMPACT— “The entorhinal cortex alvear pathway is a major excitatory input to hippocampal CA1, yet nothing is known about its physiological impact. We investigated the… | senses[0] |
| sense | and it is not a minor route - in rodent it CARRIES MOST of the entorhinal input to dorsal CA1, and its effect on the postsynaptic neurons HAS NOT, TO OUR KNOWLEDGE, BEEN REPORTED Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[1] |
| sense | with the gap dated - the synaptic boutons were described in 1996 and THE PHYSIOLOGICAL IMPACT OF THE SYNAPSES HAS NOT BEEN INVESTIGATED since Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[2] |
| sense | THE REGION STUDIED WAS CHOSEN BY THE TOOLS THAT EXISTED: the medial entorhinal cortex was chosen as the viral expression target BY VIRTUE OF THE TRANSGENIC MICE AVAILABLE Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[3] |
| sense | A DISAGREEMENT DIVIDED BY PREPARATION: SOME GROUPS observed monosynaptic suprathreshold activation after stimulation in vivo, WHEREAS OTHER GROUPS observed only subthreshold events Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[4] |
| sense | and the in vitro literature does not disagree with itself at all - ex vivo stimulation has CONSISTENTLY been found to give subthreshold responses, so the preparation is what the disagreement turns on Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[5] |
| sense | THE COMPARISON EVERYONE WOULD WANT COULD NOT BE MADE BEFORE, AND THE PAPER SAYS WHY: stimulating the distal layer activates the other pathway, this pathway's own distal terminals, AND a thalamic input, so A DIRECT COMPARISON BETWEEN THE STRENGTHS OF THE TWO WAS NOT POSSIBLE WITH PREVIOUS STUDIES Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[6] |
| sense | THE SAME TARGET REGION, TWO INPUTS, DIFFERENT INTERNEURON SUBSETS: parvalbumin cells produce LITTLE TO NO RESPONSE to distal-layer stimulation and fire strongly to this one, so the two inputs ACTIVATE DIFFERENT SUBSETS OF INTERNEURONS Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[7] |
| sense | and the selectivity was already known for the other pathway - specific subsets can be POTENTLY ACTIVATED while others are ONLY WEAKLY AFFECTED OR NOT AFFECTED AT ALL Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[8] |
| sense | NOT ALL SUBTYPES ARE EQUALLY AFFECTED: parvalbumin cells fire at higher frequencies than the other two classes, and the responsive cells span several morphological subtypes within each class Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[9] |
| sense | THE SAME PHARMACOLOGICAL TEST GIVES OPPOSITE ANSWERS FOR THE TWO RESPONSE TYPES: the potassium channel blocker rescues the excitatory response and CANNOT rescue the inhibitory one, which is what makes one monosynaptic and the other disynaptic Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[10] |
| sense | with a geometric argument doing the work the pharmacology cannot - the light was confined to the deep layers, so the terminals there MUST be the source and not the distal ones Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[11] |
| sense | and a delay difference used the same way - the interneuron delay is SIGNIFICANTLY SHORTER than the pyramidal one, which is the wrong direction for a relayed response Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[12] |
| sense | MORE THAN HALF THE INHIBITION MEASURED RATHER THAN ATTRIBUTED: silencing one interneuron class during the same stimulation removed GREATER THAN 50% of the response amplitude Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[13] |
| sense | AND THE UNTESTED PATHWAY IS THE VULNERABLE ONE: tau accumulates in the terminals of THIS pathway BUT NOT the other, so the input nobody had recorded from may be the one that fails first in Alzheimer's disease Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[14] |
| sense | with an open question left open - it is UNKNOWN whether the projection neurons whose firing tracks theta contribute to this pathway at all Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | senses[15] |
| control | the light stimulus confined to the two deep layers rather than delivered to the whole slice — held — rules out the responses arising from the same axons' terminals in the distal layer, which the pathway also reaches Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | controls[0] |
| control | sodium channel blockade followed by potassium channel blockade, applied to both response types — held — rules out a monosynaptic origin for the inhibitory response - 4-AP could not rescue the IPSCs inhibited by TTX, so inhibitory synaptic transmission driven by alvear input stimulation was NOT monosynaptic Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | controls[1] |
| control | synaptic delay measured separately for the two postsynaptic populations — held — rules out the reading that the interneuron responses are relayed rather than direct, since their delay is shorter than the pyramidal one Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | controls[2] |
| control | post hoc anatomical reconstruction of the recorded interneurons — held — rules out the possibility that the recorded cells were not the horizontally oriented population the pathway is claimed to engage Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | controls[3] |
| control | optogenetic silencing of parvalbumin interneurons during the same stimulation — held — rules out attributing the whole inhibitory response to the subtype merely because it fires most - the silencing measures its share at more than half Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | controls[4] |
| differs in | the assumption that the two entorhinal pathways engage the same interneuron population — alvear pathway terminals in the SO appear to be capable of activating different subsets of interneurons relative to TA inputs Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | claim_relations[3] |
| differs in | the disagreement about whether entorhinal stimulation drives CA1 pyramidal cells, by noting the in vitro literature is consistent where the in vivo one is not — There is some disagreement on whether stimulation of the EC in vivo is capable of eliciting suprathreshold excitation of CA1 PCs Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | claim_relations[4] |
| differs in | earlier comparisons of the two pathways' strengths, which stimulated a site that activates three inputs at once — THE AXIS IS WHAT THE STIMULATION SITE ACTUALLY ACTIVATES. 'These data may seem to suggest that the TA pathway input is stronger than the alvear pathway ... However, STIMULATION IN THE SLM WOULD ACTIVATE MORE THAN JUST TA SYNAPTIC TERMINALS.' The earlier comparison is not disputed as a measurement - it is disputed as an ATTRIBUTION, because the electrode reaches more than the pathway it was taken to test. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | claim_relations[5] |
| audit | pyramidal —contrasted-with→ interneuron — Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span shown is the abstract opening; the pyramidal/interneuron contrast is elsewhere. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[3] |
| note | pyramidal —contrasted-with→ interneuron — the inputs land on BOTH, which is why the question of what the pathway does could not be answered from anatomy alone Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[3] |
| note | PV —contrasted-with→ VIP — more than 70% of PV and VIP cells showed responses and less than 20% of the third class Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[5] |
| audit | stimulation —causes→ suprathreshold — Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span reports suprathreshold activation following stimulation in some studies; causes is loose. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[14] |
| audit | PV —distinct-from→ SLM — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but PV interneurons produce little or no response to SLM STIMULATION; distinct-from 'SLM' is loose. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[18] |
| note | PV —distinct-from→ SLM — THE SAME TARGET, TWO INPUTS, DIFFERENT INTERNEURON SUBSETS - PV cells produce LITTLE TO NO RESPONSE to distal-layer stimulation and fire strongly to this one Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[18] |
| audit | alvear —causes→ interneuron — Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span says alvear terminals appear capable of activating interneuron subsets; causes is loose. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[19] |
| note | PV —contrasted-with→ GIN — NOT ALL SUBTYPES EQUALLY AFFECTED - PV cells fire at higher frequencies than the other two classes Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[21] |
| audit | theta —causes→ excitation — Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span says theta-burst stimulation elicited excitation; 'theta' names the stimulation pattern. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[22] |
| audit | IPSC —operationalised-as→ inhibition — Audit 2026-09-28: DOUBTFUL - read against its span and kept, but IPSCs are a measure of inhibition; operationalised-as is loose. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[27] |
| note | PV —causes→ IPSC — MORE THAN HALF THE INHIBITION MEASURED RATHER THAN ATTRIBUTED - silencing one class during the same stimulation removed GREATER THAN 50% of the response amplitude Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[31] |
| note | EPSP —distinct-from→ suprathreshold — subthreshold responses in pyramidal cells EVEN UNDER ROBUST THETA BURST STIMULATION, against suprathreshold responses in the interneurons Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[33] |
| audit | GIN —is-a→ interneuron — Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span shown does not name GIN cells. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[39] |
| note | GIN —is-a→ interneuron — and the conclusion states the asymmetry plainly - the subset activated here APPEARS TO BE DIFFERENT from those activated by the other pathway Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concept_edges[39] |
| outcome (stated by the tagger, no quotation) | control — held | controls[0] |
| outcome (stated by the tagger, no quotation) | control — held | controls[1] |
| outcome (stated by the tagger, no quotation) | control — held | controls[2] |
| outcome (stated by the tagger, no quotation) | control — held | controls[3] |
| outcome (stated by the tagger, no quotation) | control — held | controls[4] |
| for which use | limitation — every result reported by interneuron type: NONE OF THESE 13 NEURONS HAD SUFFICIENT AXONAL FILL TO PERMIT ANATOMICAL IDENTIFICATION Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[0] |
| for which use | limitation — the link between the theta-coherent MEC L2 pyramidal cells and this pathway: IT IS UNKNOWN WHETHER THESE MEC L2 PCs CONTRIBUTE TO THE ALVEAR PATHWAY Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[1] |
| for which use | limitation — any ranking of the two pathways by strength: A DIRECT COMPARISON BETWEEN THE STRENGTHS OF TA AND ALVEAR INPUTS WAS NOT POSSIBLE WITH PREVIOUS STUDIES Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[2] |
| for which use | limitation — the same scope as limitations[1] - the calbindin-expressing projection neurons whose firing correlates with theta are not shown to contribute here Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[3] |
| for which use | limitation — why this region and not another: THE MEC WAS CHOSEN AS THE VIRAL EXPRESSION TARGET BY VIRTUE OF THE available transgenic line, so the anatomy studied follows the reagent Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[4] |
| for which use | limitation — the same scope as limitations[2], with the reason: SLM STIMULATION POTENTIALLY ACTIVATES ALVEAR INPUTS, so the earlier comparison does not isolate the pathway it names Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[5] |
| replication | untested | |
| limitation | Most recorded stratum oriens interneurons could not be anatomically classified because biocytin fills were insufficient. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[0] |
| limitation | Whether the theta-coherent MEC layer 2 pyramidal cells actually contribute to the alvear pathway is unknown, weakening the proposed link to theta rhythm generation. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[1] |
| limitation | The relative strength of the temporo-ammonic and alvear pathways cannot be settled from earlier work. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[2] |
| limitation | whether the recently identified projection neurons that fire with theta actually contribute to this pathway is unknown Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[3] |
| limitation | the region studied was chosen by which transgenic mice existed rather than by the question Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[4] |
| limitation | and the comparison with the other pathway cannot be made against the earlier literature, because the standard stimulation site activates both plus a third input Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[5] |
finding · quantity · variable · definition · key-term — grounded in the full text| finding | Theta burst activation of the alvear pathway never drove CA1 pyramidal cells to spike; the inputs produced only subthreshold EPSPs. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[0] |
| finding | The same alvear stimulation that fails to spike pyramidal cells does excite interneurons, which then inhibit the pyramidal cells disynaptically. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[1] |
| finding | Parvalbumin interneurons are the most responsive target of the alvear input, firing at higher rates than VIP or somatostatin (GIN) interneurons. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[2] |
| finding | Interneuron subtypes differ sharply in whether they respond at all, with O-LM/GIN cells largely unresponsive. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[3] |
| finding | Optogenetically silencing PV interneurons removed more than half of the alvear-driven inhibitory current in pyramidal cells, showing PV cells carry most of the feedforward inhibition. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[4] |
| finding | Alvear inputs onto CA1 pyramidal basal dendrites showed a low probability of transmitter release. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[5] |
| finding | The alvear pathway appears to affect CA1 mainly through feedforward inhibition via select interneuron subtypes. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[6] |
| finding | A MAJOR INPUT PATHWAY WITH NO PHYSIOLOGY ATTACHED TO IT: a MAJOR EXCITATORY INPUT to hippocampal CA1, YET NOTHING IS KNOWN ABOUT ITS PHYSIOLOGICAL IMPACT Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[7] |
| finding | and it is not a minor route - in rodent it CARRIES MOST of the entorhinal input to dorsal CA1, and its effect HAS NOT, TO OUR KNOWLEDGE, BEEN REPORTED Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[8] |
| finding | with the gap dated - the synaptic boutons were described in 1996 and THE PHYSIOLOGICAL IMPACT OF THE SYNAPSES IN THE SO HAS NOT BEEN INVESTIGATED Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[9] |
| finding | THE REGION STUDIED WAS CHOSEN BY THE TOOLS THAT EXISTED: the target was chosen BY VIRTUE OF THE TRANSGENIC MICE AVAILABLE Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[10] |
| finding | A DISAGREEMENT DIVIDED BY PREPARATION: SOME GROUPS observed monosynaptic suprathreshold activation in vivo, WHEREAS OTHER GROUPS observed only subthreshold events Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[11] |
| finding | whether in vivo stimulation excites CA1 pyramidal cells above threshold is disputed, while ex vivo stimulation has consistently given subthreshold responses Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[12] |
| finding | THE COMPARISON EVERYONE WOULD WANT COULD NOT BE MADE BEFORE: stimulating the distal layer activates three inputs at once, so A DIRECT COMPARISON BETWEEN THE STRENGTHS OF THE TWO WAS NOT POSSIBLE WITH PREVIOUS STUDIES Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[13] |
| finding | TWO INPUTS, DIFFERENT INTERNEURON SUBSETS: PV interneurons have been demonstrated to produce LITTLE TO NO RESPONSE to SLM stimulation, and alvear pathway terminals appear capable of activating DIFFERENT SUBSETS OF INTERNEURONS relative to TA inputs Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[14] |
| finding | with the selectivity already known for the other pathway - specific subsets POTENTLY ACTIVATED while others are ONLY WEAKLY AFFECTED OR NOT AFFECTED AT ALL Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[15] |
| finding | NOT ALL SUBTYPES ARE EQUALLY AFFECTED: PV cells fire at higher frequencies than the other two classes, and the responsive cells span several morphological subtypes within each class Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[16] |
| finding | THE SAME PHARMACOLOGICAL TEST GIVES OPPOSITE ANSWERS FOR THE TWO RESPONSE TYPES: the potassium channel blocker rescues the excitatory response and CANNOT rescue the inhibitory one Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[17] |
| finding | with a geometric argument doing what pharmacology cannot - the light was confined to the deep layers, so the terminals there MUST be the source Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[18] |
| finding | and a delay difference used the same way - the interneuron delay is SIGNIFICANTLY SHORTER than the pyramidal one Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[19] |
| finding | MORE THAN HALF THE INHIBITION MEASURED RATHER THAN ATTRIBUTED: silencing one interneuron class removed GREATER THAN 50% of the response amplitude Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[20] |
| finding | subthreshold responses in pyramidal cells EVEN UNDER ROBUST THETA BURST STIMULATION, against suprathreshold responses in the interneurons Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[21] |
| finding | AND THE UNTESTED PATHWAY IS THE VULNERABLE ONE: tau accumulates in the terminals of THIS pathway BUT NOT the other Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[22] |
| finding | with an open question left open - it is UNKNOWN whether the projection neurons whose firing tracks theta contribute to this pathway at all Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[23] |
| finding | and individual projection neurons do NOT correlate well with the population field potential but DO fire coherently with their own internal theta Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[24] |
| finding | the two pathways' terminals look alike where it can be measured - both facilitating, both indicative of a low probability release synapse Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[25] |
| finding | and the conclusion states the asymmetry plainly - the subset activated here APPEARS TO BE DIFFERENT from those activated by the other pathway Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[26] |
| quantity | greater than 50% — Reduction in alvear-driven inhibitory postsynaptic current in CA1 pyramidal cells when PV interneurons were optogenetically silenced Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[0] |
| quantity | 85% / 25% / 30% — Proportion of GIN, PV and VIP interneurons respectively that gave no response at all to alvear stimulation Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[1] |
| quantity | greater than 70% / less than 20% — Fraction of PV and VIP interneurons versus O-LM cells that showed alvear excitatory synaptic responses Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[2] |
| quantity | 41 of 49 — Pyramidal neurons that responded at all to optogenetic alvear stimulation Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[3] |
| quantity | 17 of 28 — Responsive stratum oriens interneurons that reached spike threshold during theta burst stimulation Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[4] |
| quantity | 16 of 37 — VIP-expressing interneurons that fired action potentials to theta burst stimulation of the alvear pathway Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[5] |
| quantity | 39 — Total interneurons recorded with somata in CA1 stratum oriens Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[6] |
| quantity | greater than 70% ... less than 20% — the share of two interneuron classes that responded against the third - the number that turns 'drives interneurons' into 'drives these interneurons' Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[7] |
| quantity | greater than 50% — the share of the inhibitory response removed by silencing one interneuron class - a contribution measured by subtraction rather than inferred from which cells fired hardest Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[8] |
| quantity | approximately 3 ms ... approximately 2 ms — the synaptic delays of alvear inputs, supporting the monosynaptic nature of alvear inputs onto PC basal dendrites in the deep layers of hippocampal CA1 Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[9] |
| value source note | quantity — THE VALUE DRAWS ON THE PAPER BEYOND THIS QUOTE: part of it is printed elsewhere in the paper, not in this quote ('alvear inputs onto CA1 interneurons was approximately 2 ms…'). | content_tags.quantities[9] |
| variable | IPSC amplitudes (dependent) Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.variables[5] |
| variable | burst action potential frequencies (dependent) Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.variables[6] |
| variable | stimulation Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.variables[8] |
| variable | theta Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.variables[9] |
| variable | synaptic delay Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.variables[10] |
| definition | alvear pathway Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[0] |
| definition | temporo-ammonic (TA) pathway Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[1] |
| definition | alvear Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[2] |
| definition | monosynaptic Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[3] |
| definition | disynaptic Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[4] |
| definition | release probability Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[5] |
| key-terms | alvear, entorhinal, hippocampal, CA1, interneuron, PV, VIP, GIN, pyramidal, EPSP, IPSC, theta, feedforward, inhibition, excitation, monosynaptic, disynaptic, optogenetic, stimulation, SLM, glutamate, TTX, release probability, transgenic, tau, rhythm, dendrite, axon, synaptic delay, suprathreshold, subthreshold |
| Shapiro-Wilk normality test | as written: Shapiro–Wilk test Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[0] |
| repeated measures ANOVA | as written: repeated measures one-way ANOVA with Bonferroni post hoc tests Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[1] |
| one-sample t-test t | as written: one sample t -tests Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[2] |
| two-way ANOVA | as written: two-way ANOVA with Bonferroni post hoc tests Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[3] |
| p-value P | as written: P values less than 0.05 Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[4] |
| standard error of the mean SEM | as written: standard error of the mean (SEM) Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[5] |
| Friedman test | Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[6] |
| nonparametric tests | as written: the appropriate nonparametric tests Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[7] |
| action potential frequency | Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.statistics[8] |
| claim type | mechanism — a second reading reaching the same value; recorded: mechanism Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | alternatives.claim_type |
| method | optogenetic activation confined to one layer, so that the responses cannot come from the same axons' terminals elsewhere — a second reading DIFFERING from the recorded value; recorded: electrophysiology Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | alternatives.method |
| phenomenon | two anatomically separate entorhinal inputs converging on the same target region by different routes — a second reading DIFFERING from the recorded value; recorded: entorhinal alvear pathway input to hippocampal CA1 Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | alternatives.phenomenon |
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