Bidirectional optogenetic control of inhibitory neurons in freely-moving mice

Bidirectional optogenetic control of inhibitory neurons in freely-moving mice Noked Levi Someck Amber-Vitos Stark

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Bidirectional optogenetic control of inhibitory neurons in freely-moving mice 2020 IEEE transactions on bio-medical engineering 10.1109/tbme.2020.3001242 Noked2020-bidirectional-optogenetic-control-of-inhibit Noked2020-bidirectional-optogenetic-control-of-inhibit.txt, the project's staged copy f568a730cc55993b01a3fe1c1c3c9db7bbaa4001 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 method Quotation withheld because this record is not cleared for redistribution. bidirectional optogenetic control of individual inhibitory neurons in freely-moving mice Quotation withheld because this record is not cleared for redistribution. system-or-tool-building system-or-tool-building Quotation withheld because this record is not cleared for redistribution. mechanisms Choosing an inhibitory (PV) opsin-expressing cell reverses the sign of the expected synaptic side-effect, so any blue-light-driven rate increase in the tagged cell must come from direct illumination rather than from trans-synaptic drive about this quote: THE QUOTE CONTINUES A SENTENCE THAT THIS COPY CUTS IN TWO - a figure caption (Fig. 9) and an author-contribution block stand between it and the words it follows, which are not adjacent to it in the extraction. Quotation withheld because this record is not cleared for redistribution. mechanisms Optically driven PV cells inhibit their postsynaptic pyramidal partners, so activating the PV cell lowers pyramidal firing and silencing it raises pyramidal firing Quotation withheld because this record is not cleared for redistribution. With excitatory-cell expression, a non-illuminated opsin-free neuron may inherit a rate increase or decrease through glutamatergic connections from directly illuminated pre-synaptic neurons - which is why the inhibitory-cell design reverses the sign and makes the inference possible. a recorded neuron can inherit a rate change it never received light for Quotation withheld because this record is not cleared for redistribution. Each dual-color unit takes about six hours of manual assembly. what this limits: any plan to build these at scale: ASSEMBLING A SINGLE DUAL-COLOR OPTICAL UNIT REQUIRES ABOUT SIX HOURS OF WORK Quotation withheld because this record is not cleared for redistribution. Unit weight over 0.5 g caps how many can be mounted on a small animal. what this limits: how many units a small animal can carry: EACH UNIT WEIGHS OVER 0.5 g Quotation withheld because this record is not cleared for redistribution. Only a fraction of PV interneurons expressed both opsins, so not all blue-responsive cells were also red-responsive. what this limits: the bidirectional control claim for the population: A THIRD LIMITING FACTOR IS THE PERCENTAGE OF PV INTERNEURONS WITH DOUBLE EXPRESSION OF BOTH CaMKII AND JAWS Quotation withheld because this record is not cleared for redistribution. The inference from a rate increase to direct illumination carries a named exception, and it is stated inside the sentence the conclusion is drawn from. what this limits: reading a light-evoked rate increase in an inhibitory cell as direct activation: the paper states this holds with the caveat of disynaptic dis-inhibition Quotation withheld because this record is not cleared for redistribution. The design space is bounded by what is commercially available and by the physical envelope, not by what the experiment would ideally need. what this limits: the wavelengths and powers available in this device: the diodes were chosen to fit a 3.8 mm can, a 100 mA maximal current limitation and low threshold currents Quotation withheld because this record is not cleared for redistribution. The design space was bounded by the model before it was bounded by experiment: butt-coupling was excluded on modelled grounds, so the reported geometry is the survivor of a simulated elimination rather than a measured comparison. Quotation withheld because this record is not cleared for redistribution. The simple astigmatic Gaussian beam model, a solution of the paraxial Helmholtz equation from laser-beam physics, is imported to predict coupling efficiency and set the optical pathway lengths of the implantable neural device. Quotation withheld because this record is not cleared for redistribution. a baseline recording period of at least 15 minutes preceding photostimulation in every session eliminates: that the spiking and LFP changes attributed to photostimulation were already present before the light was applied · outcome: held Quotation withheld because this record is not cleared for redistribution. disynaptic dis-inhibition disynaptic dis-inhibition Quotation withheld because this record is not cleared for redistribution. predictive model predictive model Quotation withheld because this record is not cleared for redistribution. laser diode laser diode Quotation withheld because this record is not cleared for redistribution. ChR2 ChR2 Quotation withheld because this record is not cleared for redistribution. rate increase rate increase Quotation withheld because this record is not cleared for redistribution. evidence of direct optogenetic activation - a rate increase after blue light, whose interpretation REVERSES depending on whether the opsin-expressing cell is excitatory or inhibitory about this quote: THE QUOTE CONTINUES A SENTENCE THAT THIS COPY CUTS IN TWO - a figure caption (Fig. 9) and an author-contribution block stand between it and the words it follows, which are not adjacent to it in the extraction. Quotation withheld because this record is not cleared for redistribution. feasibility - established by a PREDICTIVE MODEL of alternative optical designs before any unit was built, so the design was selected against a model rather than against measurements Quotation withheld because this record is not cleared for redistribution. rate increase - evidence of DIRECT illumination only because the illuminated cell is inhibitory, so the synaptic route would lower the rate; the one surviving alternative, disynaptic dis-inhibition, is named as a caveat about this quote: THE QUOTE CONTINUES A SENTENCE THAT THIS COPY CUTS IN TWO - a figure caption (Fig. 9) and an author-contribution block stand between it and the words it follows, which are not adjacent to it in the extraction. Quotation withheld because this record is not cleared for redistribution. extends → the authors' earlier GRIN-lens waveguide dual-color device (references [16], [17]) Quotation withheld because this record is not cleared for redistribution. extends → previous demonstrations of activating and silencing the same neuron in brain slices, a head-fixed mouse and a freely-moving rat (references [8], [26], [16], [15]) Quotation withheld because this record is not cleared for redistribution. rate increase —distinct-from→ disynaptic dis-inhibition rate increase disynaptic dis-inhibition strength of the relation: 0.9 · about this quote: THE QUOTE CONTINUES A SENTENCE THAT THIS COPY CUTS IN TWO - a figure caption (Fig. 9) and an author-contribution block stand between it and the words it follows, which are not adjacent to it in the extraction. · note: THE PAPER NAMES THE CONFOUND IN THE SENTENCE THAT MAKES THE INFERENCE. Choosing an INHIBITORY cell reverses the expected synaptic sign, so a rate increase after blue light can only be direct illumination - 'with the caveat of disynaptic dis-inhibition'. The design turns a confound into a signature, and the one route that survives is stated in the same breath rather than left to a reader. Quotation withheld because this record is not cleared for redistribution. Mann-Whitney U test Mann-Whitney U test Quotation withheld because this record is not cleared for redistribution. binomial test binomial test Quotation withheld because this record is not cleared for redistribution. Poisson test Poisson test Quotation withheld because this record is not cleared for redistribution. effect size effect size Quotation withheld because this record is not cleared for redistribution. principal component analysis principal component analysis Quotation withheld because this record is not cleared for redistribution. Gaussian mixture model Gaussian mixture model about this quote: THE QUOTE CONTINUES A SENTENCE THAT THIS COPY CUTS IN TWO - a figure caption (Fig. 6) and a running head stand between it and the words it follows, which are not adjacent to it in the extraction. Quotation withheld because this record is not cleared for redistribution. confidence bands confidence bands Quotation withheld because this record is not cleared for redistribution. mean and standard deviation mean and standard deviation Quotation withheld because this record is not cleared for redistribution. standard error of the mean standard error of the mean Quotation withheld because this record is not cleared for redistribution. The dual-color unit delivered 454±271 µW at 450 nm and 8.65±2.26 mW at 638 nm at the fiber tip at 100 mA. Quotation withheld because this record is not cleared for redistribution. The blue and red illumination profiles from the shared fiber overlapped by 46%. Quotation withheld because this record is not cleared for redistribution. The two wavelengths did not interact optically: their spectra at the fiber end were separate and no spectral interference occurred during simultaneous dual-color illumination. Quotation withheld because this record is not cleared for redistribution. Nine of 74 interneurons (12%) were controlled bidirectionally through the same fiber, raising their spike rate under blue light and lowering it under red light. Quotation withheld because this record is not cleared for redistribution. Blue light produced stronger effects than red light. Quotation withheld because this record is not cleared for redistribution. The second-order effects on pyramidal cells were strictly sign-appropriate for inhibition: no pyramidal cell was excited by blue light and none was suppressed by red light. Quotation withheld because this record is not cleared for redistribution. Laser heating did not exceed 7 °C even under prolonged pulsed illumination. Quotation withheld because this record is not cleared for redistribution. Wide-band recordings during blue and red illumination were clean. Quotation withheld because this record is not cleared for redistribution. The paper claims the first conclusive demonstration that a single identified neuron can be both activated and silenced in a freely-moving animal. Quotation withheld because this record is not cleared for redistribution. The approach's main cost is labour: each dual-color optical unit takes roughly six hours to assemble. Quotation withheld because this record is not cleared for redistribution. SAG model SAG model Quotation withheld because this record is not cleared for redistribution. driving current driving current Quotation withheld because this record is not cleared for redistribution. spike rate spike rate Quotation withheld because this record is not cleared for redistribution. light power light power Quotation withheld because this record is not cleared for redistribution. device temperature device temperature Quotation withheld because this record is not cleared for redistribution. epochs with no stimulation epochs with no stimulation Quotation withheld because this record is not cleared for redistribution. inhibitory cell type inhibitory cell type Quotation withheld because this record is not cleared for redistribution. 454±271 µW and 8.65±2.26 mW — Light power at the etched fiber tip at 100 mA drive current for the 450 nm and 638 nm laser diodes respectively Quotation withheld because this record is not cleared for redistribution. 46% — Spatial overlap (intersection over union) of the blue and red illumination profiles at the fiber tip Quotation withheld because this record is not cleared for redistribution. 630±55 mg — Average weight of one assembled dual-color optical unit Quotation withheld because this record is not cleared for redistribution. 2.77 g — Weight of a complete implantation-ready four-shank dual-color probe with microdrive Quotation withheld because this record is not cleared for redistribution. 230 — Total number of well-isolated cells recorded from neocortex and CA1 across the three mice Quotation withheld because this record is not cleared for redistribution. 36 of 80 INT; 45% — Proportion of recorded interneurons that increased their spike rate during blue-light illumination Quotation withheld because this record is not cleared for redistribution. 37/77, 48% — Proportion of recorded interneurons that decreased their spike rate during red-light illumination through the same fiber Quotation withheld because this record is not cleared for redistribution. 9/74 of the INT; 12% — Proportion of interneurons controlled bidirectionally (activated by blue and silenced by red) Quotation withheld because this record is not cleared for redistribution. h= 0.61±0.04 — Effect size of the blue-light-driven firing-rate increase in responsive interneurons Quotation withheld because this record is not cleared for redistribution. 7 °C — Maximum on-head temperature rise of the laser can during prolonged illumination in a behaving mouse Quotation withheld because this record is not cleared for redistribution. under 31°C — Peak bench-test temperature of an optical unit under prolonged high-load operation, below mammalian body temperature Quotation withheld because this record is not cleared for redistribution. 1.14±0.11 MΩ — Impedance of each silicon-probe recording site measured at 1 kHz in saline Quotation withheld because this record is not cleared for redistribution. 14.9±5.3 MΩ — Electrical isolation between diode anode-cathode and the grounded Faraday shield, high enough to make EMI negligible Quotation withheld because this record is not cleared for redistribution. three freely-moving male mice — Number of animals implanted, all heterozygous for PV-Cre and expressing ChR2 and Jaws in PV interneurons Quotation withheld because this record is not cleared for redistribution. about six hours — Assembly time for a single dual-color optical unit, the method's main practical cost Quotation withheld because this record is not cleared for redistribution.

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