Hippocampal GABAergic transmission: a new target for adenosine control of excitability

J Neurochem. 2016 Dec;139(6):1056-1070. doi: 10.1111/jnc.13872. Epub 2016 Dec 14.

Abstract

Physiological network functioning in the hippocampus is dependent on a balance between glutamatergic cell excitability and the activity of diverse local circuit neurons that release the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Tuners of neuronal communication such as adenosine, an endogenous modulator of synapses, control hippocampal network operations by regulating excitability. Evidence has been recently accumulating on the influence of adenosine on different aspects of GABAergic transmission to shape hippocampal function. This review addresses how adenosine, through its high-affinity A1 (A1 R) and A2A receptors (A2A R), interferes with different GABA-mediated forms of inhibition in the hippocampus to regulate neuronal excitability. Adenosine-mediated modulation of phasic/tonic inhibitory transmission, of GABA transport mechanisms and its interference with other modulatory systems are discussed together with the putative implications for neuronal function in physiological and pathological conditions. This article is part of a mini review series: 'Synaptic Function and Dysfunction in Brain Diseases'.

Keywords: GABAergic transmission; adenosine receptors; hippocampus; interneurons; neuronal excitability.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / metabolism*
  • Adenosine / pharmacology
  • Animals
  • GABAergic Neurons / metabolism*
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Humans
  • Nerve Net / drug effects
  • Nerve Net / metabolism
  • Receptors, Purinergic P1 / metabolism
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology*
  • gamma-Aminobutyric Acid / metabolism*
  • gamma-Aminobutyric Acid / pharmacology

Substances

  • Receptors, Purinergic P1
  • gamma-Aminobutyric Acid
  • Adenosine