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Updated: Jul 16, 2026

Isolation of Targeted Hypothalamic Neurons for Studies of Hormonal, Metabolic, and Electrical Regulation
09:29

Isolation of Targeted Hypothalamic Neurons for Studies of Hormonal, Metabolic, and Electrical Regulation

Published on: August 4, 2023

Electrical inhibition of identified anorexigenic POMC neurons by orexin/hypocretin

Xiaosong Ma1, Lejla Zubcevic, Jens C Brüning

  • 1University Laboratory of Physiology, Oxford OX1 3PT, United Kingdom.

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience
|February 16, 2007
PubMed

Insights

Orexin peptides reduce the electrical activity of appetite-suppressing Proopiomelanocortin (POMC) neurons in the hypothalamus. This inhibition, mediated by synaptic changes, may explain how orexins promote feeding behavior.

Area of Science:

  • Neuroscience
  • Endocrinology
  • Molecular Biology

Background:

  • Proopiomelanocortin (POMC) neurons in the arcuate nucleus (ARC) regulate appetite and energy balance.
  • Dysfunction of POMC neurons or POMC-derived peptides is linked to obesity.
  • Orexins, known wakefulness promoters, are found near ARC POMC neurons, but their direct effect is unknown.

Purpose of the Study:

  • To investigate the direct effect of orexins on the electrical activity of ARC POMC neurons.
  • To elucidate the cellular mechanisms underlying orexin's influence on POMC neuron function.

Main Methods:

  • Identification of living ARC POMC neurons in mouse brain slices using green fluorescent protein.
  • Whole-cell patch-clamp recordings to assess neuronal electrical activity.
  • Analysis of synaptic inputs and membrane potential changes.

Main Results:

  • Orexin significantly suppresses spontaneous action potential firing in ARC POMC neurons.
  • Orexin-induced inhibition involves membrane hyperpolarization.
  • Orexin alters synaptic drive, decreasing excitatory and increasing inhibitory (GABAergic) inputs.

Conclusions:

  • Orexin directly inhibits the electrical activity of hypothalamic POMC neurons.
  • This inhibition is mediated by presynaptic changes in synaptic input.
  • Reduced POMC neuron activity by orexin may contribute to orexin's appetite-enhancing effects.

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