Optogenetic Stimulation of the Corticothalamic Pathway Affects Relay Cells and GABAergic Neurons Differently in the Mouse Visual Thalamus

Abstract The ventral pallidum (VP) regulates motivation, drug addiction, and several behaviors that rely on heightened arousal. However, the role and underlying neural circuits of the VP in the control of wakefulness remain poorly understood. In the present study, we sought to elucidate the specific role of VP GABAergic neurons in controlling sleep–wake behaviors in mice. Fiber photometry revealed that the population activity of VP GABAergic neurons was increased during physiological transitions from non-rapid eye movement (non-REM, NREM) sleep to either wakefulness or REM sleep. Moreover, chemogenetic and optogenetic manipulations were leveraged to investigate a potential causal role of VP GABAergic neurons in initiating and/or maintaining arousal. In vivo optogenetic stimulation of VP GABAergic neurons innervating the ventral tegmental area (VTA) strongly promoted arousal via disinhibition of VTA dopaminergic neurons. Functional in vitro mapping revealed that VP GABAergic neurons, in principle, inhibited VTA GABAergic neurons but also inhibited VTA dopaminergic neurons. In addition, optogenetic stimulation of terminals of VP GABAergic neurons revealed that they promoted arousal by innervating the lateral hypothalamus, but not the mediodorsal thalamus or lateral habenula. The increased wakefulness chemogenetically evoked by VP GABAergic neuronal activation was completely abolished by pretreatment with dopaminergic D1 and D2/D3 receptor antagonists. Furthermore, activation of VP GABAergic neurons increased exploration time in both the open-field and light–dark box tests but did not modulate depression-like behaviors or food intake. Finally, chemogenetic inhibition of VP GABAergic neurons decreased arousal. Taken together, our findings indicate that VP GABAergic neurons are essential for arousal related to motivation.

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066 Noradrenaline and acetylcholine inhibit sleep-promoting neurons of ventrolateral preoptic area through a local GABAergic circuit

SLEEP ◽

10.1093/sleep/zsab072.065 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A27-A28

Author(s):

Roberto De Luca ◽

Stefano Nardone ◽

Lin Zhu ◽

Elda Arrigoni

Keyword(s):

Muscarinic Receptors ◽

Inhibitory Action ◽

Preoptic Area ◽

Brain Slices ◽

Inhibitory Effect ◽

Gabaergic Neurons ◽

Optogenetic Stimulation ◽

Direct Inhibitory Effect ◽

Afferent Inputs ◽

Stimulation Of

Abstract Introduction The ventrolateral preoptic (VLPO) nucleus is a key area involved in the initiation and maintenance of sleep. During wakefulness, sleep-promoting galanin neurons in the VLPO are directly inhibited by arousal signals including noradrenaline and acetylcholine. We have found that while these neurotransmitters directly inhibit VLPO galanin neurons, they also activate GABAergic neurons in the VLPO that do not express galanin. We propose that when activated by monoaminergic and cholinergic inputs, these local VLPO GABAergic neurons provide an additional inhibition of the VLPO galanin sleep-promoting neurons. We tested this model in brain slices in mice. Methods We studied VLPO galanin neurons in mouse brain slices using patch-clamp recordings. We recorded from fluorescently labeled VLPO galanin neurons following the injection of a cre-dependent AAV encoding for mCherry, into the VLPO of Gal-cre mice. For the optogenetic studies we expressed channelrhodopsin-2 (ChR-2) in VLPO VGAT neurons and mCherry in galanin neurons by injecting a flp-dependent and a cre-dependent AAV encoding respectively for ChR2 and mCherry into the VLPO of VGAT-flp::Gal-cre mice. We photo-stimulated local GABAergic neurons and recorded from labeled VLPO galanin neurons. Noradrenaline, carbachol and receptor antagonists were bath-applied. Results Noradrenaline and carbachol inhibited VLPO galanin neurons by alpha-2 and muscarinic receptors and these effects were maintained in the presence of tetrodotoxin (TTX) indicating, as previously proposed, a direct inhibitory effect of noradrenaline and carbachol on VLPO galanin neurons. In addition, both noradrenaline and carbachol increased the frequency of spontaneous inhibitory post-synaptic currents (sIPSCs) of VLPO galanin neurons, suggesting an additional inhibitory action on VLPO galanin neurons. Finally, optogenetic stimulation of local VLPO GABAergic neurons produced short latency, TTX-resistant, opto-evoked IPSCs in VLPO galanin neurons. Both noradrenaline and carbachol increased the amplitude of these opto-evoked IPSCs by the activation of alpha-1 and muscarinic receptors. Conclusion Our results demonstrate that noradrenaline and acetylcholine inhibit VLPO galanin neurons directly and indirectly. Both noradrenaline and acetylcholine increase GABAergic afferent inputs to VLPO galanin neurons by activating local GABAergic neurons. We propose that during wakefulness this feedforward inhibition provides additional inhibition of VLPO galanin sleep-promoting neurons. Support (if any) NS091126 and HL149630

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Differential roles of pyramidal and fast-spiking, GABAergic neurons in the control of glioma cell proliferation

10.1101/2020.03.05.978825 ◽

2020 ◽

Author(s):

Elena Tantillo ◽

Eleonora Vannini ◽

Chiara Cerri ◽

Cristina Spalletti ◽

Antonella Colistra ◽

...

Keyword(s):

Cell Proliferation ◽

Glioma Cell ◽

Pyramidal Neurons ◽

Visual Stimulation ◽

Afferent Input ◽

Gabaergic Neurons ◽

Optogenetic Stimulation ◽

Glioma Cell Proliferation ◽

Fast Spiking ◽

Stimulation Of

AbstractRecent studies have demonstrated an active role for neurons in glioma progression. Specifically, peritumoral neurons establish functional excitatory synapses with glioma cells, and optogenetic stimulation of cortical pyramidal neurons drives tumor progression. However, the specific role of different subsets of cortical neurons, such as GABAergic interneurons, remains unexplored. Here, we directly compared the effects of optogenetic stimulation of pyramidal cells vs. fast-spiking, GABAergic neurons. In mice inoculated with GL261 cells into the motor cortex, we show that optogenetic stimulation of pyramidal neurons enhances glioma cell proliferation. In contrast, optogenetic stimulation of fast-spiking, parvalbumin-positive interneurons reduces proliferation as measured by BrdU incorporation and Ki67 immunolabelling. Since both principal cells and fast-spiking interneurons are directly activated by sensory afferent input, we next placed tumors in the occipital cortex to test the impact of visual stimulation/deprivation. We report that total lack of visual input via dark rearing enhances the density of proliferating glioma cells, while daily visual stimulation by gratings of different spatial frequencies and contrast reduces tumor growth. The effects of sensory input are region-specific, as visual deprivation has no significant effect on tumor proliferation in mice with gliomas in the motor cortex. We also report that sensory stimulation combined with temozolomide administration delays the loss of visual responses in peritumoral neurons. Altogether, these data demonstrate complex effects of different neuronal subtypes in the control of glioma proliferation.HighlightsActivity of GABAergic neurons reduces glioma cell proliferationLevels of sensory afferent input regulate tumor proliferationEffects of sensory input are region-specific

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Optogenetic Stimulation of GABAergic Neurons in the Globus Pallidus Produces Hyperkinesia

Frontiers in Behavioral Neuroscience ◽

10.3389/fnbeh.2018.00185 ◽

2018 ◽

Vol 12 ◽

Cited By ~ 7

Author(s):

Jun Tian ◽

Yaping Yan ◽

Wang Xi ◽

Rui Zhou ◽

Huifang Lou ◽

...

Keyword(s):

Globus Pallidus ◽

Gabaergic Neurons ◽

Optogenetic Stimulation ◽

Stimulation Of

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074 Basal Forebrain GABAergic Neurons Promote Arousal by Disinhibiting the Orexin Neurons via Local GABAergic Interneurons

SLEEP ◽

10.1093/sleep/zsab072.073 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A31-A31

Author(s):

Michela Cristofolini ◽

Roberto De Luca ◽

Anne Venner ◽

Loris Ferrari ◽

Kevin Grace ◽

...

Keyword(s):

Basal Forebrain ◽

Viral Vector ◽

Brain Slices ◽

Nrem Sleep ◽

Gabaergic Neurons ◽

Gabaergic Interneurons ◽

Optogenetic Stimulation ◽

Stimulation Of

Abstract Introduction Optogenetic and chemogenetic studies have shown that activation of basal forebrain (BF) GABAergic neurons rapidly wakes up mice from non-REM (NREM) sleep. These wake-promoting responses have been attributed to BF GABAergic neurons projecting to the cerebral cortex and more specifically to the inhibition of cortical fast-spiking interneurons. Tracing studies have however found that BF GABAergic neurons also densely innervate the lateral hypothalamus (LH) perifornical area, although the role of this pathway in behavioral state control remains mostly unexplored. Methods We conducted in vivo and in vitro optogenetic studies. We selectively expressed channelrhodopsin-2 (ChR2) in BF GABAergic neurons by injecting a cre-dependent viral vector encoding for ChR2 into the BF of VGAT-cre mice. We photostimulated the BF GABAergic input to the LH with optical fibers placed into the LH of EEG instrumented mice. For in vitro recordings we expressed ChR2 in BF GABAergic neurons and we fluorescently labeled orexin or LH GABAergic neurons. We recorded in brain slices from identified orexin neurons or GABA neurons while photostimulating the BF GABAergic input. Results Optogenetic stimulation of the BF GABAergic fibers in the LH produced rapid arousals from NREM sleep. The same stimulation however did not wake up the mice if they were in REM sleep. We conducted additional studies in brain slices to identify the postsynaptic neurons in the LH targeted by the BF GABAergic input. We found that while optogenetic stimulation of the BF GABAergic input did not produce opto-evoked synaptic responses in the orexin neurons, it produced short-latency opto-evoked inhibitory postsynaptic currents (IPSCs) in LH GABAergic neurons. These opto-evoked IPSCs were GABAA receptor-mediated and were maintained in tetrodotoxin (TTX) indicating monosynaptic connectivity. We have previously found that orexin neurons are inhibited by local LH GABAergic neurons. Our hypothesis is that these local GABAergic interneurons are the target of the BF GABAergic arousal input. Conclusion BF GABAergic neurons drive arousal through projections to the LH. We propose that this arousal response is due to the inhibition of local GABAergic interneurons which in turn disinhibit the LH wake-promoting neurons including the orexin neurons. Support (if any) NS091126 and HL149630

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Fast and reversible neural inactivation in macaque cortex by optogenetic stimulation of GABAergic neurons

eLife ◽

10.7554/elife.52658 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 2

Author(s):

Abhishek De ◽

Yasmine El-Shamayleh ◽

Gregory D Horwitz

Keyword(s):

Neural Activity ◽

Neural Circuits ◽

Gabaergic Neurons ◽

Visual Sensitivity ◽

Cell Type ◽

Behavioral Deficits ◽

Inhibitory Cell ◽

Optogenetic Stimulation ◽

Cell Type Specific ◽

Stimulation Of

Optogenetic techniques for neural inactivation are valuable for linking neural activity to behavior but they have serious limitations in macaques. To achieve powerful and temporally precise neural inactivation, we used an adeno-associated viral (AAV) vector carrying the channelrhodopsin-2 gene under the control of a Dlx5/6 enhancer, which restricts expression to GABAergic neurons. We tested this approach in the primary visual cortex, an area where neural inactivation leads to interpretable behavioral deficits. Optical stimulation modulated spiking activity and reduced visual sensitivity profoundly in the region of space represented by the stimulated neurons. Rebound firing, which can have unwanted effects on neural circuits following inactivation, was not observed, and the efficacy of the optogenetic manipulation on behavior was maintained across >1000 trials. We conclude that this inhibitory cell-type-specific optogenetic approach is a powerful and spatiotemporally precise neural inactivation tool with broad utility for probing the functional contributions of cortical activity in macaques.

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Decision letter: Fast and reversible neural inactivation in macaque cortex by optogenetic stimulation of GABAergic neurons

10.7554/elife.52658.sa1 ◽

2019 ◽

Author(s):

Michael Schmid ◽

Wim Vanduffel ◽

David Sheinberg

Keyword(s):

Gabaergic Neurons ◽

Optogenetic Stimulation ◽

Stimulation Of

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Author response: Fast and reversible neural inactivation in macaque cortex by optogenetic stimulation of GABAergic neurons

10.7554/elife.52658.sa2 ◽

2020 ◽

Author(s):

Abhishek De ◽

Yasmine El-Shamayleh ◽

Gregory D Horwitz

Keyword(s):

Gabaergic Neurons ◽

Author Response ◽

Optogenetic Stimulation ◽

Stimulation Of

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Selective Optogenetic Stimulation of Glutamatergic, but not GABAergic, Vestibular Nuclei Neurons Induces Immediate and Reversible Postural Imbalance in Mice

10.1101/2020.09.03.281980 ◽

2020 ◽

Author(s):

Q. Montardy ◽

M. Wei ◽

T. Yi ◽

X. Liu ◽

Z. Zhou ◽

...

Keyword(s):

Vestibular Nuclei ◽

Gabaergic Neurons ◽

Support Surface ◽

List Type ◽

Optogenetic Stimulation ◽

Short Period ◽

Locomotor Deficits ◽

Locomotor Behaviors ◽

Stimulation Of

AbstractGlutamatergic and GABAergic neurons represent the neural components of the medial vestibular nuclei. We assessed the functional role of glutamatergic and GABAergic neuronal pathways arising from the vestibular nuclei (VN) in the maintenance of gait and balance by optogenetically stimulating the VN in VGluT2-cre and GAD2-cre mice. We demonstrate that glutamatergic, but not GABAergic VN neuronal subpopulation is responsible for immediate and strong posturo-locomotor deficits, comparable to unilateral vestibular deafferentation models. During optogenetic stimulation, the support surface dramatically increased in VNVGluT2+ mice, and rapidly fell back to baseline after stimulation, whilst it remained unchanged during similar stimulation of VNGAD2+ mice. This effect persisted when vestibular compensation was removed. Posturo-locomotor alterations evoked in VNVGluT2+ animals were still present immediately after stimulation, while they disappeared 1h later. Overall, these results indicate a fundamental role for VNVGluT2+ neurons in balance and posturo-locomotor functions, but not for VNGAD2+ neurons, in this specific context. This new optogenetic approach will be useful to characterize the role of the different VN neuronal populations involved in vestibular physiology and pathophysiology.HighlightsFor the first time, Vestibular nuclei were optogenetically stimulated in free-moving animals, to asses for glutamatergic and GABAergic neurons functions in posturo-locomotor behaviors.Brief optogenetic activation of VNVGluT2+, but not VNGAD2+, induced immediate and strong postural deficit.Stimulation of VNVGluT2+ neurons provoked an imbalance with continuous effect on locomotion for a short period of time after stimulation.These results are comparable to the classical vestibular deafferentation models during their peak of deficit, and set optogenetic stimulation as a new model to study vestibular deficits.

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