Name: optogenetics identification of a neuronal type with a glass optrode in awake mice
Uploaded: 2018-06-28T14:30:00
Description: Watch this Scientific Journal Video about Optogenetics Identification of a Neuronal Type with a Glass Optrode in Awake Mice at JoVE.com

The authors were supported by the Japan Society for the Promotion of Science KAKENHI Grant JP16K11200 and 17H02223, and the Grant for Research from Kanazawa Medical University S2016-8 and C2017-3. We thank Yuhichi Kuda for his support in taking the photos.

All procedures are done in accordance with the guiding principles of the Physiological Society of Japan and with the approval of the Animal Care Committee of Kanazawa Medical University.
1. Construction of the Glass Optrode Holder
NOTE: To build a glass optrode holder, a commercial electrode holder is used (Figure 1A).
<ol>
	<li>Gently pull out the steel tube for pressure control from the barrel of the holder.</li>
	<li>By drilling, b...

<ol>
	<li>Rajasethupathy, P., Ferenczi, E., Deisseroth, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeting+neural+circuits.">Targeting neural circuits.</a> Cell. 165 (3), 524-534 (2016).</li><li>Gore, F., Schwartz, E. C., Salzman, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manipulating+neural+activity+in+physiologically+classified+neurons:+triumphs+and+challenges.">Manipulating neural activity in physiologically classified neurons: triumphs and challenges.</a> Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 370 (1677), 20140216 (2015).</li><li>Ono, M., Bishop, D. C., Oliver, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identified+GABAergic+and+glutamatergic+neurons+in+the+mouse+inferior+colliculus+share+similar+response+properties.">Identified GABAergic and glutamatergic neurons in the mouse inferior colliculus share similar response properties.</a> Journal of Neuroscience. 37 (37), 8952-8964 (2017).</li><li>Ono, M., Bishop, D. C., Oliver, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-lasting+sound-evoked+afterdischarge+in+the+auditory+midbrain.">Long-lasting sound-evoked afterdischarge in the auditory midbrain.</a> Scientific Reports. 6, 20757 (2016).</li><li>Munoz, W., Tremblay, R., Rudy, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Channelrhodopsin-assisted+patching:+in+vivo+recording+of+genetically+and+morphologically+identified+neurons+throughout+the+brain.">Channelrhodopsin-assisted patching: in vivo recording of genetically and morphologically identified neurons throughout the brain.</a> Cell Reports. 9 (6), 2304-2316 (2014).</li><li>Lima, S. Q., Hromadka, T., Znamenskiy, P., Zador, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PINP:+a+new+method+of+tagging+neuronal+populations+for+identification+during+in+vivo+electrophysiological+recording.">PINP: a new method of tagging neuronal populations for identification during in vivo electrophysiological recording.</a> PLoS One. 4 (7), e6099 (2009).</li><li>Kuwada, S., Batra, R., Stanford, T. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monaural+and+binaural+response+properties+of+neurons+in+the+inferior+colliculus+of+the+rabbit:+effects+of+sodium+pentobarbital.">Monaural and binaural response properties of neurons in the inferior colliculus of the rabbit: effects of sodium pentobarbital.</a> Journal of Neurophysiology. 61 (2), 269-282 (1989).</li><li>Populin, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anesthetics+change+the+excitation/inhibition+balance+that+governs+sensory+processing+in+the+cat+superior+colliculus.">Anesthetics change the excitation/inhibition balance that governs sensory processing in the cat superior colliculus.</a> Journal of Neuroscience. 25 (25), 5903-5914 (2005).</li><li>Duque, D., Malmierca, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimulus-specific+adaptation+in+the+inferior+colliculus+of+the+mouse:+anesthesia+and+spontaneous+activity+effects.">Stimulus-specific adaptation in the inferior colliculus of the mouse: anesthesia and spontaneous activity effects.</a> Brain Structure and Function. 220 (6), 3385-3398 (2015).</li><li>Cai, R., Richardson, B. D., Caspary, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Responses+to+predictable+versus+random+temporally+complex+stimuli+from+single+units+in+auditory+thalamus:+impact+of+aging+and+anesthesia.">Responses to predictable versus random temporally complex stimuli from single units in auditory thalamus: impact of aging and anesthesia.</a> Journal of Neuroscience. 36 (41), 10696-10706 (2016).</li><li>Zhao, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+type-specific+channelrhodopsin-2+transgenic+mice+for+optogenetic+dissection+of+neural+circuitry+function.">Cell type-specific channelrhodopsin-2 transgenic mice for optogenetic dissection of neural circuitry function.</a> Nature Methods. 8 (9), 745-752 (2011).</li><li>Ito, T., Bishop, D. C., Oliver, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two+classes+of+GABAergic+neurons+in+the+inferior+colliculus.">Two classes of GABAergic neurons in the inferior colliculus.</a> Journal of Neuroscience. 29 (44), 13860-13869 (2009).</li><li>Ono, M., Yanagawa, Y., Koyano, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GABAergic+neurons+in+inferior+colliculus+of+the+GAD67-GFP+knock-in+mouse:+electrophysiological+and+morphological+properties.">GABAergic neurons in inferior colliculus of the GAD67-GFP knock-in mouse: electrophysiological and morphological properties.</a> Neuroscience Research. 51 (4), 475-492 (2005).</li><li>Chen, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+neural+activity+using+Thy1-GCaMP+transgenic+mice.">Imaging neural activity using Thy1-GCaMP transgenic mice.</a> Neuron. 76 (2), 297-308 (2012).</li><li>Hirai, Y., Nishino, E., Ohmori, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+recording+of+fluorescence+and+electrical+signals+by+photometric+patch+electrode+in+deep+brain+regions+in+vivo.">Simultaneous recording of fluorescence and electrical signals by photometric patch electrode in deep brain regions in vivo.</a> Journal of Neurophysiology. 113 (10), 3930-3942 (2015).</li><li>LeChasseur, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+microprobe+for+parallel+optical+and+electrical+recordings+from+single+neurons+in+vivo.">A microprobe for parallel optical and electrical recordings from single neurons in vivo.</a> Nature Methods. 8 (4), 319-325 (2011).</li><li>Abaya, T. V., Blair, S., Tathireddy, P., Rieth, L., Solzbacher, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+3D+glass+optrode+array+for+optical+neural+stimulation.">A 3D glass optrode array for optical neural stimulation.</a> Biomedical Optics Express. 3 (12), 3087-3104 (2012).</li><li>Bittner, K. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conjunctive+input+processing+drives+feature+selectivity+in+hippocampal+CA1+neurons.">Conjunctive input processing drives feature selectivity in hippocampal CA1 neurons.</a> Nature Neuroscience. 18 (8), 1133-1142 (2015).</li></ol>

Optogenetics has become a powerful tool in neuroscience. It has been utilized for identifying specific neuron types in vivo as well as manipulating the activities of specific neuronal pathways. The clarification of the neural activities of different neuronal types promotes the understanding of the mechanism of the neural circuits. Here, we demonstrated a method to deliver the light to the recording site through a glass electrode in the IC of awake VGAT-ChR2 mice.
There are several cri...

The central nervous system consists of various types of neurons, which have different functions. How these different types of neurons work within the neural circuit is one of the major concerns in neuroscience. However, in many brain regions, it has been impossible to distinguish the neuronal types in in vivo recordings of electrical activities because there is no clear difference in the electrical spike signal itself, with some exceptions. Recent advances in optogenetics have made a breakthrough1,2. Using transgenic animals in which light-sensitive opsin (e.g., channelrhodopsin-2) is expressed in specific neuronal types, it became possible to distinguish the neuronal types efficiently in in vivo recordings3,4,5,6. In these animals, the neurons with light-sensitive opsin are excited by giving light stimuli during the electrical recordings, but other neurons are not. The opsin-positive neurons, therefore, are easily distinguished from other neuron types by their responses to light.
In optogenetics experiments, it is critical to deliver the light to the recording site. As a non-invasive method, the light is often directed from the brain&#39;s surface. However, because the light&#39;s strength reduces as it goes through brain tissue, it is hard to stimulate the deep brain regions from the brain&#39;s surface. Especially, it is difficult for the stimulation light to reach the deep brain regions when the optical transparency of the brain surface is low, as is often the case with recordings from awake animals. Electrophysiological experiments have often been performed on anesthetized animals because the body movement causes noise in the recordings. As is well documented, however, anesthesia is known to change the neural responses7,8,9,10. Thus, it is necessary to use awake animals in order to study neural responses without the artificial effects of anesthesia. Unlike the experiments with anesthetized animals, the electrophysiological recordings are performed after the recovery from surgery in the experiments with awake animals. During the interval between the surgery and the recordings, the tissue exudate often accumulates on the brain surface and makes the optical transparency of the brain surface low.
Here, we describe a method to record single-unit recordings from an awake mouse using a custom-made glass optrode. In this method, the light is delivered through the recording glass electrode so that it is possible to reliably stimulate the recorded neuron with light in deep brain regions. This custom-made optrode system consists of accessible and inexpensive materials and is easy to assemble.

<table border="0" cellpadding="0" cellspacing="0" style="width:971px;" width="971">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:247px;">Electrode holder</td>
			<td style="width:140px;">Molecular Device</td>
			<td style="width:393px;">1-HL-U</td>
			<td style="width:191px;">pipette holder for microelectrode amplifier</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Ceramic split mating sleeve</td>
			<td>Thorlabs</td>
			<td>ADAF1</td>
			<td>f2.5 mm ferrule</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Circuit board spacer</td>
			<td>Teishin Denki</td>
			<td>SPA-320</td>
			<td>f8.0 mm, 20.0 mm long</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Stereotaxic frame for mice</td>
			<td>Narishige</td>
			<td>SR-6M-HT</td>
			<td>Stereotaxic instruments for mice</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Manipulator</td>
			<td>Narishige</td>
			<td>NA</td>
			<td>Manual manipulator</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Superbond</td>
			<td>Sun Medical</td>
			<td>M: 204610557</td>
			<td>Dental adhesive resin cement</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Form2</td>
			<td>Formlabs</td>
			<td>NA</td>
			<td>3D printer</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Kwik-Sil</td>
			<td>WPI</td>
			<td>KWIK-SIL</td>
			<td>Low toxicity silicone adhesive</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Borosilicate glass capillaries</td>
			<td>Narishige</td>
			<td>GD-1.5</td>
			<td>OD 1.5 mm, ID 0.9 mm, 90.0 mm long</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Fiber-optic patch cord</td>
			<td>Doric Lenses</td>
			<td>MFP_960/1000/2200-0.63_1m_FCM-ZF2.5</td>
			<td>Monofiberoptic patchcord, OD, 2.5 mm, core = 960 mm, cladding = 1000 mm, NA = 0.63</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Connectrized LED</td>
			<td>Doric Lenses</td>
			<td>LEDC-1B_FC</td>
			<td>Central wave length = 465 nm, output power = 45 mW (Core 960 mm 0.63 NA )</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">LED driver</td>
			<td>Doric Lenses</td>
			<td>LEDRV_1CH_1000</td>
			<td>1 ch LED driver, maximum output = 1000 mA</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Electrode puller</td>
			<td>Narishige</td>
			<td>PB-7</td>
			<td>Dual-stage glass micropipette puller</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:247px;">Borosilicate glass capillary</td>
			<td style="width:140px;">Narishige</td>
			<td style="width:393px;">GD-1.5</td>
			<td style="width:191px;">Bolosilicate glass capillary, OD, 1.5mm, ID, 0.9 mm, 90.0 mm long</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">GENTACIN</td>
			<td>MSD CO., Ltd</td>
			<td>185711173</td>
			<td>Antibiotic ointment</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Terramycin&#174;-LA</td>
			<td>Zoetis</td>
			<td>G 333</td>
			<td>Oxytetracycline</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Tg(Slc32a1- COP4*H134R/EYFP)8Gfng/J</td>
			<td>Jackson Labs</td>
			<td>#14548</td>
			<td>VGAT-ChR2 mice</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Multiclamp 700B</td>
			<td>Molecular Devices</td>
			<td>2500-0157</td>
			<td>Microelectrode amplifier</td>
		</tr>
	</tbody>
</table>

optogenetics identification of a neuronal type with a glass optrode in awake mice

It is a major concern in neuroscience how different types of neurons work in neural circuits. Recent advances in optogenetics have enabled the identification of the neuronal type in in vivo electrophysiological experiments in broad brain regions. In optogenetics experiments, it is critical to deliver the light to the recording site. However, it is often hard to deliver the stimulation light to the deep brain regions from the brain&#39;s surface. Especially, it is difficult for the stimulation light to reach the deep brain regions when the optical transparency of the brain surface is low, as is often the case with recordings from awake animals. Here, we describe a method to record spike responses to the light from an awake mouse using a custom-made glass optrode. In this method, the light is delivered through the recording glass electrode so that it is possible to reliably stimulate the recorded neuron with light in the deep brain regions. This custom-made optrode system consists of accessible and inexpensive materials and is easy to assemble.

In Figure 2, we examined the effects of the tip size and the length of the glass pipettes on the light power at the tip of the pipettes (Figure 2A-B). The light power was measured by an optical power meter placed 1 mm away from the tip. The full length was set to 50 &#177; 2 mm when the tip size varied, while the tip size was set to 2.5 &#181;m when the full length varied. The shank of the glass pipette was set t...

Watch this Scientific Journal Video about Optogenetics Identification of a Neuronal Type with a Glass Optrode in Awake Mice at JoVE.com

Optogenetics Identification of a Neuronal Type with a Glass Optrode in Awake Mice

This work introduces a method to perform an optogenetic single-unit recording reliably from an awake mouse using a custom-made glass optrode.

It is a major concern in neuroscience how different types of neurons work in neural circuits. Recent advances in optogenetics have enabled the ...

This method can help answer key questions in the neuroscience field, such as the functions of different types of neurons. The main advantage of this technique is that it makes it possible to reliably identify the different types of neurons in vivo with inexpensive and accessible materials. I will be demonstrating the procedure together with Shinji Muramoto, our technician, and Lanlan Ma, our assistant professor from our laboratory.To begin this procedure, gently pull out the steel tube for pressure control from the barrel of the holder. Broaden the hole of the pin seat side in the barrel of the holder by drilling. Then, place a stainless steel pipe in the hole.Next, insert a ceramic split mating sleeve for 2.5 millimeter diameter ferrule into the hole. Make a hole in an L-shaped rabbit and attach the barrel of the electrode holder to the rabbit with epoxy adhesive. Subsequently, attach it to a manipulator with screws.Prepare a custom-built head post by making the columnar circuit board spacer into a cuboidal shape with a milling cutter, and cut it into two head posts with a saw. Then, flatten the bottom of the head post with a milling cutter. Before the surgery, sterilize all the surgical instruments and a head post with an autoclave.Clean the stereotaxic frame and the heating pad with 70 percent alcohol. Next, anesthetize the mouse and place it in the stereotaxic frame on a heating pad. In this experiment, a transgenic mouse in which the inhibitory neurons expressing channelrhodopsin-II is used.Place the teeth in the hole of the bite bar and lightly tighten the nose clamp. Subsequently, fix both sides of the head using ear bars. When the head is correctly fixed by the ear bars, tighten the nose clamp.Apply an ophthalmic ointment to the eyes. Trim the hair over the head with small scissors and clean the scalp with a cotton swab of chlorhexidine gluconate. Then, cut the scalp along the midline and push it aside.Remove the periosteum with a cotton swab dipped in 70 percent alcohol and let the skull dry. Then, attach the head post to the manipulator. Position the head post flat on the skull around the bregma using the manipulator.Mix four drops of the monomer, one drop of catalyst, and one small small spoon of polymer on a small dish that is chilled in the refrigerator. Apply dental cement on the frontal and parietal bone and fix the head post to the skull. After the dental cement has hardened, remove the mouse from the stereotaxic frame.Apply an antibiotic ointment on the exposed skin and inject a cocktail of medetomidine antagonist and antibiotic. Then, place the mouse on the heat pad in a cage until it awakes and return it to a housing cage with enrichments. To perform craniotomy over the target brain region for recording, clean the skull with a cotton swab soaked with chlorhexidine gluconate and 70 percent alcohol.Carefully scrape the skull over the recording site with a dental drill. When the bone is thin enough, cut it with the tip of the scalpel and remove it. Then apply dental cement around the exposed region in order to strengthen the skull.Cover the exposed brain area with silicone adhesive after the dental cement has hardened. Then, place the animal on the heat pad in a cage until it awakes, and return it to a housing cage. Allow the animal to recover for at least one day after craniotomy, before performing the electrophysiological recording.Before performing the electrophysiological recording, make some glass pipettes from borosilicate glass capillaries using an electrode puller. Fill the pipettes with 10 millimolar PBS. In some recordings, two percent neurobiotin is added to the 10 millimolar PBS.Next, place the animal in the recording chamber. Attach a filled glass pipette to the custom-made optrode holder. Insert a silver chloride coated wire into the glass pipette.Afterward, connect the pin to the head stage of the recording amplifier. Subsequently, connect the fiber-optic patch cord with a zirconia ferrule to the split mating sleeve on the optrode holder. Push the patch cord into the sleeve until the tip of the ferrule contacts the back of the glass pipette.The patch cord delivers the light from LED, which is controlled by a single-channel LED driver. Afterward, remove the silicone adhesive over the craniotomy. Apply warm saline on the brain surface periodically to prevent the brain surface from drying during the recording session.If necessary, remove the dura with sharp tweezers. Here, the spike responses were recorded in the inferior colliculus of the awake VGAT channelrhodopsin-II mice. In the inferior colliculus of the VGAT channelrhodopsin-II mice, the GABAergic neurons specifically express channelrhodopsin-II.In the awake mice, both the GABAergic and glutamatergic neurons were excited or suppressed respectively when they were given light stimuli. When the light stimulus is delivered through the glass electrode, it evoked spike responses in some neurons. In contrast, in other neurons, the light stimuli suppressed the spike responses evoked by sound stimuli.These results show that a glass optrode can record the well-isolated single unit activity and reliably stimulate the recorded neurons by light. After the development, this technique paved the way for researchers in the field of neuroscience to explore how different types of neurons work in the neural socket of various brain regions.

Research

JoVE Journal

Neuroscience

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system ...

Preparation of an Awake Mouse for Recording Neural Responses and Injecting Tracers

It is well known that anesthesia alters neural response properties in various regions of the brain.13.  In the auditory system, fundamental response ...

Fast Micro-iontophoresis of Glutamate and GABA: A Useful Tool to Investigate Synaptic Integration

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of ...

A Procedure for Implanting Organized Arrays of Microwires for Single-unit Recordings in Awake, Behaving Animals

In vivo electrophysiological recordings in the awake, behaving animal provide a powerful method for understanding neural signaling at the single-cell ...

Super-resolution Imaging of Neuronal Dense-core Vesicles

Detection of fluorescence provides the foundation for many widely utilized and rapidly advancing microscopy techniques employed in modern biological and ...

Inducing Plasticity of Astrocytic Receptors by Manipulation of Neuronal Firing Rates

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be ...

Extracellular Recording of Neuronal Activity Combined with Microiontophoretic Application of Neuroactive Substances in Awake Mice

Differences in the activity of neurotransmitters and neuromodulators, and consequently different neural responses, can be found between anesthetized and ...

Combining Optogenetics with Artificial microRNAs to Characterize the Effects of Gene Knockdown on Presynaptic Function within Intact Neuronal Circuits

The purpose of this protocol is to characterize the effect of gene knockdown on presynaptic function within intact neuronal circuits. We describe a ...

Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice

Extensive data on relationships of neural network oscillations to behavior and organization of neuronal discharge across brain regions call for new tools ...