Chemogenetic synaptic silencing of neural circuits localizes a hypothalamus→midbrain pathway for feeding behavior

Neuron. 2014 May 21;82(4):797-808. doi: 10.1016/j.neuron.2014.04.008. Epub 2014 Apr 24.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agouti-Related Protein / genetics
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Channelrhodopsins
  • Clozapine / analogs & derivatives
  • Clozapine / pharmacology
  • Feeding Behavior / drug effects
  • Feeding Behavior / physiology*
  • Humans
  • Hypothalamus / cytology*
  • Hypothalamus / drug effects
  • In Vitro Techniques
  • Membrane Potentials / drug effects
  • Membrane Potentials / genetics
  • Mesencephalon / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Models, Molecular
  • Molecular Sequence Data
  • Nerve Net / drug effects
  • Nerve Net / physiology*
  • Neural Inhibition / drug effects
  • Neural Inhibition / genetics
  • Neural Inhibition / physiology
  • Neurons / cytology
  • Neurons / drug effects
  • Neurons / metabolism*
  • Receptor, Muscarinic M4 / genetics
  • Receptor, Muscarinic M4 / metabolism
  • Repressor Proteins / genetics
  • Time Factors

Substances

  • Agouti-Related Protein
  • Agrp protein, mouse
  • Basic Helix-Loop-Helix Transcription Factors
  • Channelrhodopsins
  • Receptor, Muscarinic M4
  • Repressor Proteins
  • Sim1 protein, mouse
  • Clozapine
  • clozapine N-oxide

Associated data

  • GENBANK/KJ685217