Ambient GABA modulates septo-hippocampal inhibitory terminals via presynaptic GABAb receptors

Neuropharmacology. 2015 Jan;88:55-62. doi: 10.1016/j.neuropharm.2014.10.005.

Abstract

The septo-hippocampal GABAergic pathway connects inhibitory neurons in the medial septum with hippocampal interneurons. Phasic release of GABA from septo-hippocampal terminals is thought to play an important role in shaping hippocampal network activity during behavior. Here, we found that GABA release from septo-hippocampal terminals is under negative feedback from the hippocampal local inhibitory network. We found that the strength of septo-hippocampal GABAergic inhibition is constrained by presynaptic GABAb receptors that are activated by ambient GABA during states of increased hippocampal network activity.

MeSH terms

  • Animals
  • Female
  • Gene Knock-In Techniques
  • Hippocampus / physiology*
  • Interneurons / physiology
  • Male
  • Mice, 129 Strain
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Neural Inhibition / physiology*
  • Neural Pathways / physiology
  • Patch-Clamp Techniques
  • Presynaptic Terminals / physiology*
  • Receptors, GABA-B / metabolism*
  • Septum of Brain / physiology*
  • Tissue Culture Techniques
  • gamma-Aminobutyric Acid / metabolism*

Substances

  • Receptors, GABA-B
  • gamma-Aminobutyric Acid