Role of GABA in Central Respiratory Control Studied in Mice Lacking GABA-Synthesizing Enzyme 67-kDa Isoform of Glutamic Acid Decarboxylase

Abstract

In in vivo adult mammals, the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) has been shown to play an essential role in the termination of the respiratory phase in the central respiratory rhythm generator.1, 2, 3 On the other hand, works with in vitro brainstem-spinal cord preparations have revealed that the respiratory rhythm of neonatal rats is unaffected by blockade of GABAergic and glycinergic receptors.4—6 These results suggest that either GABAergic or glycinergic synaptic inhibition is not essential for the generation of respiratory rhythm in neonatal mammals. We recently analyzed the role of GABA in the generation of respiratory rhythm and pattern and reported that GABA plays an important role in the maintenance of regular respiratory rhythm and normal inspiratory pattern in neonatal mice7. However, the precise role of GABA in the generation of respiratory rhythm and pattern in neonatal mammals is not well understood at the level of respiratory neurons.