Interneurons

Interneurons Freund Kali

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Interneurons 2008 Scholarpedia 10.4249/scholarpedia.4720 Freund2008-interneurons Freund2008-interneurons.txt, the project's staged copy 4f2c83f8a972a6aff25d73db1eb35cdb5896289c not-redistributable neuroscience

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0 spans located by searching the stored text for the quote's exact words, allowing any whitespace between them the classification of cortical inhibitory interneurons and what their diversity is for Quotation withheld because this record is not cleared for redistribution. which measurable differences between interneurons should be allowed to define distinct cell types Quotation withheld because this record is not cleared for redistribution. sets a functional criterion for admitting new interneuron types, organises the known classes by input source and target compartment, and reports the in vivo evidence that anatomically defined classes are functionally homogeneous Quotation withheld because this record is not cleared for redistribution. mechanism Quotation withheld because this record is not cleared for redistribution. cortical inhibitory interneurons Quotation withheld because this record is not cleared for redistribution. review review Quotation withheld because this record is not cleared for redistribution. mechanisms Kv3-family potassium channel expression gives parvalbumin basket cells their fast-spiking phenotype, which is what allows them to respond with minimal delay and sustain high-frequency firing Quotation withheld because this record is not cleared for redistribution. mechanisms interneuron-driven synchronization of principal cell firing produces coincident spikes, which are a more effective trigger of firing downstream and therefore raise transmission efficiency Quotation withheld because this record is not cleared for redistribution. mechanisms synchronized principal cell firing facilitates synaptic potentiation and thereby the formation of the potentiated cell ensembles that carry memory traces Quotation withheld because this record is not cleared for redistribution. mechanisms O-LM feed-back inhibition blocks plasticity of entorhinal inputs at the theta trough, but pyramidal cells firing ahead of the population in phase precession escape that inhibition and so can potentiate their inputs Quotation withheld because this record is not cleared for redistribution. mechanisms feed-forward and feed-back inhibition reduce the number of simultaneously active principal cells, producing sparse representations useful for sensory coding and long-term memory Quotation withheld because this record is not cleared for redistribution. mechanisms feedback inhibition sets up winner-take-all competition among principal cells, so that one cell's increased activity suppresses its neighbours Quotation withheld because this record is not cleared for redistribution. a rule is stated for when a measured difference may create a new category: only when it is causally linked to a functional dichotomy Quotation withheld because this record is not cleared for redistribution. the failure mode of dropping that rule is named - admitting every measurable feature yields an astronomical number of types Quotation withheld because this record is not cleared for redistribution. the discriminating question is put in evolutionary terms: which features are adaptations for the job and which are side products that merely survived Quotation withheld because this record is not cleared for redistribution. the classification is built from input-output properties, because those determine the morphology rather than the other way round Quotation withheld because this record is not cleared for redistribution. the tree is then branched twice - first by whether the target is another interneuron, then by which compartment of the principal cell is targeted Quotation withheld because this record is not cleared for redistribution. the anatomical taxonomy is checked against an independent criterion: firing phase relative to naturally occurring population rhythms in vivo Quotation withheld because this record is not cleared for redistribution. and passes, with each anatomically defined class showing characteristic phase-locked patterns Quotation withheld because this record is not cleared for redistribution. a simpler homologous system is chosen for dissection precisely because its lamination lets connectivity be read off position Quotation withheld because this record is not cleared for redistribution. the possibility that the observed diversity is an artefact of the slice preparation is raised rather than assumed away Quotation withheld because this record is not cleared for redistribution. two named types are flagged as possibly one type with an unlabelled axon Quotation withheld because this record is not cleared for redistribution. a continuum between two axonal arbour patterns is acknowledged where the scheme wants discrete types Quotation withheld because this record is not cleared for redistribution. the compartment logic is derived from function: dendrites are where plasticity happens, the perisomatic region is where output is decided Quotation withheld because this record is not cleared for redistribution. Direct evidence about what interneurons actually do in cortical computation is scarce relative to descriptive anatomical and physiological data. what this limits: any functional claim in the review: COMPARED TO THE ABUNDANCE OF INFORMATION ON THE MORPHOLOGICAL, PHYSIOLOGICAL, AND MOLECULAR PROPERTIES ... THERE IS STILL A RELATIVE[ly small amount on what they do] Quotation withheld because this record is not cleared for redistribution. Physiological classifications may be artefacts of in vitro recording conditions rather than properties of interneurons in the behaving animal. what this limits: the physiological classification itself: AT LEAST SOME OF THE DIFFERENCES SEEN IN PHYSIOLOGICAL BEHAVIOR MAY RESULT FROM THE ARTIFICIAL RECORDING CONDITIONS IN VITRO, AND A DIFFERENT CLASSIFICATION may follow from different conditions Quotation withheld because this record is not cleared for redistribution. The molecular identity of at least one reviewed cell class is unsettled. what this limits: results reported for this cell class: THE MOLECULAR CHARACTERISTICS OF THIS CELL TYPE ARE CONTROVERSIAL, BUT MAY INCLUDE THE EXPRESSION OF CB AND/OR PV Quotation withheld because this record is not cleared for redistribution. the criterion demands function, and direct functional evidence is admitted to be scarce duplicate of: limitations[0] · what this limits: the same scope as limitations[0] - direct functional evidence is scarce next to the descriptive anatomical and physiological literature Quotation withheld because this record is not cleared for redistribution. the functions of the neocortical dendritic-inhibitory types in particular have been hard to identify what this limits: the neocortical dendritic-inhibitory types: THE PRECISE FUNCTIONS OF THESE NEOCORTICAL CELL TYPES HAVE BEEN DIFFICULT TO IDENTIFY Quotation withheld because this record is not cleared for redistribution. some physiological diversity may be an artefact of in vitro recording conditions duplicate of: limitations[1] · what this limits: the same scope as limitations[1] - some physiological diversity may be an artefact of the in vitro recording conditions rather than a property of the cells Quotation withheld because this record is not cleared for redistribution. the molecular characterisation of bistratified cells is contested duplicate of: limitations[2] · what this limits: the same scope as limitations[2] - the molecular characterisation of bistratified cells is contested Quotation withheld because this record is not cleared for redistribution. the stabilisation account of interneuron function is described by the authors as simplistic where epilepsy is concerned what this limits: the stabilisation account of interneuron function: IT OFFERS A SIMPLISTIC EXPLANATION FOR THE CRITICAL INVOLVEMENT OF INTERNEURONS IN EPILEPSY Quotation withheld because this record is not cleared for redistribution. a single dendritic inhibitory cell contributes negligibly on its own, so claims about their function require synchrony that is not always demonstrated what this limits: any functional claim about a single dendritic inhibitory cell: they PROVIDE 2 TO 20 SYNAPSES ONTO A SINGLE TARGET PYRAMIDAL CELL, WHICH ARE SCATTERED ALL OVER THE DENDRITIC TREE, so the claim is implicitly about a synchronised population Quotation withheld because this record is not cleared for redistribution. the adaptation versus neutral side-product distinction, imported as the test for whether a measured feature may define a cell type Quotation withheld because this record is not cleared for redistribution. the impedance profile and resonance, used to explain why particular cell classes participate in particular frequency bands Quotation withheld because this record is not cleared for redistribution. sparse representation as a design goal, imported to give feed-forward and feed-back inhibition a shared computational purpose Quotation withheld because this record is not cleared for redistribution. Interneuron-Selective interneurons Interneuron-Selective interneurons Quotation withheld because this record is not cleared for redistribution. interneuron - defined by local axons, versus the class called long-range interneurons which explicitly fails that definition and keeps the name anyway Quotation withheld because this record is not cleared for redistribution. a cell type - as any reproducible difference in morphology or physiology, versus only those differences causally tied to a functional dichotomy; the article insists on the second Quotation withheld because this record is not cleared for redistribution. a measured feature - as an adaptation for the cell's job versus as a surviving side product; the distinction that decides whether it may define a type Quotation withheld because this record is not cleared for redistribution. inhibition - feed-forward, driven from outside the target territory, versus feed-back, driven by the very population it inhibits Quotation withheld because this record is not cleared for redistribution. inhibitory target - dendritic, controlling plasticity of incoming excitation, versus perisomatic, controlling whether output is generated at all Quotation withheld because this record is not cleared for redistribution. GABAergic effect - hyperpolarising in general, but possibly depolarising at the axon initial segment, which would reverse what axo-axonic cells do Quotation withheld because this record is not cleared for redistribution. physiological classification - as measured in vitro versus as it might appear in the behaving animal; the first may create diversity the second would not show Quotation withheld because this record is not cleared for redistribution. claim_type: method a second reading DIFFERING from the recorded value. Recorded: mechanism — note: a second reading, verbatim-verified, disagreeing with the value on the record. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. method: curated synthesis of anatomical, neurochemical, physiological and in vivo recording evidence, organised around a functional classification criterion a second reading DIFFERING from the recorded value. Recorded: review — note: a second reading, verbatim-verified, disagreeing with the value on the record. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. phenomenon: cortical inhibition and the division of labour among interneuron types a second reading DIFFERING from the recorded value. Recorded: cortical inhibitory interneurons — note: a second reading, verbatim-verified, disagreeing with the value on the record. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. builds-on → Freund (2003) Quotation withheld because this record is not cleared for redistribution. critiques → classification schemes that generate cell types from any measurable morphological or physiological difference differs in: THE AXIS IS WHETHER THE FEATURE IS CAUSALLY LINKED TO FUNCTION. 'differences in morphological ... or physiological features ... should be used to generate new cell types only if these differences are causally linked [to function].' The critique does not say morphology is the wrong feature - it says a feature earns its place in a classification only through a causal link, which is a condition on the METHOD of classifying, not on the features. Quotation withheld because this record is not cleared for redistribution. critiques → the proposal that a functional cell class requires a conjunction of anatomical and physiological features, which would give an astronomical number of types differs in: THE AXIS IS THE COST OF THE CRITERION, AND THE PAPER PRICES IT. 'Quotation withheld.' A classification rule is not refuted - it is followed to its consequence, and the consequence is that the class stops being useful. Its [1] in this corpus carries the remedy: a feature counts only if CAUSALLY LINKED to function. Quotation withheld because this record is not cleared for redistribution. supports → Somogyi and Klausberger, that anatomically and neurochemically defined classes are functionally homogeneous in vivo Quotation withheld because this record is not cleared for redistribution. builds-on → Freund and Buzsaki and subsequent reviews of interneuron diversity Quotation withheld because this record is not cleared for redistribution. supports → the proposal that PV basket cell ensembles are the indispensable clockwork of cortical oscillation, with CCK ensembles superimposed as a tuning system Quotation withheld because this record is not cleared for redistribution. critiques → the simple runaway-excitation account of interneuron function as an explanation of epilepsy Quotation withheld because this record is not cleared for redistribution. Interneurons —contrasted-with→ principal cells Interneurons principal cells strength of the relation: 1 Quotation withheld because this record is not cleared for redistribution. feed-forward inhibition —contrasted-with→ feed-back inhibition feed-forward inhibition feed-back inhibition strength of the relation: 1 Quotation withheld because this record is not cleared for redistribution. Perisomatic Inhibitory cells —contrasted-with→ Dendritic Inhibitory cells Perisomatic Inhibitory cells Dendritic Inhibitory cells the relation itself is separately evidenced · strength of the relation: 1 · the relation stated: the two classes are separated by the principal-cell compartment they target, and the paper calls the two kinds of inhibition functionally distinct Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span writes 'inhibition targeting pyramidal cell dendrites' / 'the perisomatic region', not the two cell classes. Quotation withheld because this record is not cleared for redistribution. Interneuron-Selective interneurons —part-of→ Interneurons Interneuron-Selective interneurons Interneurons strength of the relation: 0.95 Quotation withheld because this record is not cleared for redistribution. axo-axonic —part-of→ Perisomatic Inhibitory cells axo-axonic Perisomatic Inhibitory cells strength of the relation: 0.95 Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span says perisomatic cells innervate somata, proximal dendrites OR AXON INITIAL SEGMENTS; 'axo-axonic' is not named, so part-of rests on that gloss. Quotation withheld because this record is not cleared for redistribution. basket cells —part-of→ Perisomatic Inhibitory cells basket cells Perisomatic Inhibitory cells strength of the relation: 0.95 Quotation withheld because this record is not cleared for redistribution. O-LM —part-of→ Dendritic Inhibitory cells O-LM Dendritic Inhibitory cells strength of the relation: 0.9 Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span writes 'dendritic interneurons', not 'Dendritic Inhibitory cells'. Quotation withheld because this record is not cleared for redistribution. Perisomatic Inhibitory cells —causes→ gamma Perisomatic Inhibitory cells gamma strength of the relation: 0.9 Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span is cut before the role of perisomatic cells in rhythms is stated. Quotation withheld because this record is not cleared for redistribution. long-range interneurons —distinct-from→ Interneurons long-range interneurons Interneurons strength of the relation: 0.9 Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but long-range interneurons do NOT MEET the definition but are commonly called interneurons; distinct-from is loose. Quotation withheld because this record is not cleared for redistribution. Interneurons —causes→ sparse representations Interneurons sparse representations strength of the relation: 0.85 Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but endpoint by anaphora: 'feed-forward and feed-back inhibition' = inhibition by interneurons (previous sentences). Quotation withheld because this record is not cleared for redistribution. The article argues that interneuron classification is only meaningful when morphological or physiological differences map onto a functional dichotomy, rather than being catalogued for their own sake. Quotation withheld because this record is not cleared for redistribution. Interneuron diversity increases with the complexity of local networks in a brain area. Quotation withheld because this record is not cleared for redistribution. In vivo recordings from anatomically identified cells show each anatomical/neurochemical class has its own characteristic phase relationship to theta, gamma and ripples, supporting functional homogeneity of the anatomical classes. Quotation withheld because this record is not cleared for redistribution. PV basket cells strongly increase their firing during sharp waves while CCK basket cells do not. Quotation withheld because this record is not cleared for redistribution. The article restates the proposal that PV basket-cell ensembles are an indispensable oscillatory clockwork of cortex. Quotation withheld because this record is not cleared for redistribution. Newly described ivy cells, marked by nitric oxide synthase and neuropeptide Y, may outnumber parvalbumin cells and thus displace them as the most abundant hippocampal interneuron. Quotation withheld because this record is not cleared for redistribution. A single dendritic inhibitory cell's contribution to controlling principal-cell dendrites is likely negligible. Quotation withheld because this record is not cleared for redistribution. each anatomically and neurochemically defined class has characteristic phase-locked firing relative to theta, gamma and ripples Quotation withheld because this record is not cleared for redistribution. PV and CCK basket cells both synchronize principal cells at theta and gamma but divide labour, behaving differently during sharp waves. Quotation withheld because this record is not cleared for redistribution. CCK basket cells receive far less local glutamatergic input than PV cells and are selectively innervated by median raphe serotonergic afferents. Quotation withheld because this record is not cleared for redistribution. EVIDENCE CORRECTED (RE-GROUNDED - THE POINTER WAS WRONG, NOT THE CLAIM) · each axo-axonic cell contacts the axon initial segments of about 1000-1500 pyramidal cells EVIDENCE CORRECTED: RE-GROUNDED - THE POINTER WAS WRONG, NOT THE CLAIM. The old evidence was verbatim, anchored and correctly cut, and it contained NONE of this claim's numbers (1000, 1500). The paper states the claim in one sentence elsewhere and the tagger did not use it. the project, 2026-08-23: 'WE HAVE SPENT THE DAY VERIFYING THAT QUOTES ARE REAL AND NONE OF IT ASKS WHETHER THEY ARE RELEVANT.' Confirmed by reading the claim, the old span and the candidate together; the candidate carries every number AND the claim's own content words. Quotation withheld because this record is not cleared for redistribution. each basket cell targets about 1500-2000 principal cells Quotation withheld because this record is not cleared for redistribution. axo-axonic GABA-A effects may be depolarising, which would make them synchronisers rather than silencers Quotation withheld because this record is not cleared for redistribution. PV basket cells express Kv3 channels, which underlie fast-spiking and minimal response delay Quotation withheld because this record is not cleared for redistribution. Ivy cells may be more numerous than PV cells, previously thought the most abundant hippocampal interneuron Quotation withheld because this record is not cleared for redistribution. a single dendritic inhibitory cell makes only 2 to 20 synapses on a target pyramidal cell, so these cells must act in synchrony Quotation withheld because this record is not cleared for redistribution. pyramidal cells firing in phase-precession mode can escape O-LM feedback inhibition, so their entorhinal synapses can be potentiated Quotation withheld because this record is not cleared for redistribution. HS cells have extremely long dendrites, suggesting they monitor global population synchrony Quotation withheld because this record is not cleared for redistribution. interneuron diversity increases with the complexity of the local network Quotation withheld because this record is not cleared for redistribution. interneuron interneuron Quotation withheld because this record is not cleared for redistribution. feed-forward inhibition feed-forward inhibition Quotation withheld because this record is not cleared for redistribution. feed-back inhibition feed-back inhibition Quotation withheld because this record is not cleared for redistribution. Dendritic Inhibitory cells Dendritic Inhibitory cells Quotation withheld because this record is not cleared for redistribution. Perisomatic Inhibitory cells Perisomatic Inhibitory cells Quotation withheld because this record is not cleared for redistribution. long-range interneurons long-range interneurons Quotation withheld because this record is not cleared for redistribution. phase precession phase precession Quotation withheld because this record is not cleared for redistribution. resonance resonance Quotation withheld because this record is not cleared for redistribution. Interneurons Interneurons Quotation withheld because this record is not cleared for redistribution. feed-forward feed-forward Quotation withheld because this record is not cleared for redistribution. Interneuron-Selective interneurons Interneuron-Selective interneurons Quotation withheld because this record is not cleared for redistribution. axo-axonic axo-axonic Quotation withheld because this record is not cleared for redistribution. phase precession phase precession Quotation withheld because this record is not cleared for redistribution. long-range interneurons long-range interneurons Quotation withheld because this record is not cleared for redistribution. 1000-1500 — number of pyramidal cell axon initial segments innervated by a single axo-axonic (chandelier) cell Quotation withheld because this record is not cleared for redistribution. 1500-2000 — number of principal cells whose somata and proximal dendrites a single basket cell targets Quotation withheld because this record is not cleared for redistribution. 2 to 20 — number of synapses a single dendritic inhibitory cell makes onto one target pyramidal cell Quotation withheld because this record is not cleared for redistribution. 4-8 Hz and 30-100 Hz — the theta and gamma frequency bands at which perisomatic inhibitory cells rhythmically synchronize principal cell activity Quotation withheld because this record is not cleared for redistribution. 800 to 1,700 µm — measured extent of axonal arbours of intracellularly labelled hippocampal axo-axonic cells Quotation withheld because this record is not cleared for redistribution. at least three times — how much more glutamatergic synaptic input PV basket cells receive relative to CCK basket cells Quotation withheld because this record is not cleared for redistribution. about 400 by 800 µm — area covered by the axonal arbour of an O-LM interneuron in the transverse and longitudinal planes Quotation withheld because this record is not cleared for redistribution. about 1 mm — transverse extent of hippocampal basket cell axonal arbours Quotation withheld because this record is not cleared for redistribution. 1000-1500 pyramidal cells — axon initial segments contacted by one axo-axonic cell Quotation withheld because this record is not cleared for redistribution. 1500-2000 — principal cells targeted by one basket cell Quotation withheld because this record is not cleared for redistribution. theta (4-8 Hz) and gamma (30-100 Hz) — the frequency bands perisomatic cells synchronise Quotation withheld because this record is not cleared for redistribution. 2 to 20 synapses — contacts made by one dendritic inhibitory cell on one pyramidal cell Quotation withheld because this record is not cleared for redistribution. 800 to 1,700 µm — axonal arbour extent of labelled hippocampal axo-axonic cells Quotation withheld because this record is not cleared for redistribution. phase-locked phase-locked Quotation withheld because this record is not cleared for redistribution. impedance profile impedance profile Quotation withheld because this record is not cleared for redistribution. firing pattern firing pattern Quotation withheld because this record is not cleared for redistribution. principal cell compartment principal cell compartment Quotation withheld because this record is not cleared for redistribution. calcium binding protein content calcium binding protein content Quotation withheld because this record is not cleared for redistribution.

The full text of this article is not redistributable, so it is not included here. The evidence sentences are withheld with it; the tag layer and its grounding status remain. The article itself is at https://doi.org/10.4249/scholarpedia.4720.