Chemogenetic synaptic silencing of neural circuits localizes a hypothalamus→midbrain pathway for feeding behavior.
Brain function is mediated by neural circuit connectivity, and elucidating the role of connections is aided by techniques to block their output. We developed cell-type-selective, reversible synaptic inhibition tools for mammalian neural circuits by leveraging G protein signaling pathways to suppress synaptic vesicle release. Here, we find that the pharmacologically selective designer Gi-protein-coupled receptor hM4D is a presynaptic silencer in the presence of its cognate ligand clozapine-N-oxide (CNO). Activation of hM4D signaling sharply reduced synaptic release probability and synaptic current amplitude. To demonstrate the utility of this tool for neural circuit perturbations, we developed an axon-selective hM4D-neurexin variant and used spatially targeted intracranial CNO injections to localize circuit connections from the hypothalamus to the midbrain responsible for feeding behavior. This synaptic silencing approach is broadly applicable for cell-type-specific and axon projection-selective functional analysis of diverse neural circuits.
Janelia Farm Research Campus, HHMI, 19700 Helix Drive, Ashburn, VA 20147, USA; Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
Tevye J
TJ
Stachniak
Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Neuroscience Discovery and Translation Area, Pharma Research and Development, F. Hoffmann-La Roche, 4070 Basel, Switzerland.
Anirvan
A
Ghosh
Janelia Farm Research Campus, HHMI, 19700 Helix Drive, Ashburn, VA 20147, USA. Electronic address: sternsons@janelia.hhmi.org.
Scott M
SM
Sternson
D054369:Agouti-Related Protein / Q000235:genetics; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics; D000075402:Channelrhodopsins; D003024:Clozapine / Q000031:analogs & derivatives / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007031:Hypothalamus / Q000166:cytology* / Q000187:drug effects; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects / Q000235:genetics; D008636:Mesencephalon / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology*; D009433:Neural Inhibition / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D043588:Receptor, Muscarinic M4 / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D013997:Time Factors
D054369:Agouti-Related Protein; D051792:Basic Helix-Loop-Helix Proteins; D000075402:Channelrhodopsins; D003024:Clozapine; D043588:Receptor, Muscarinic M4; D012097:Repressor Proteins; C515199:Agrp protein, mouse; C101750:Sim1 protein, mouse; C079149:clozapine N-oxide