Respiratory depression produced by injection of GABA into the fourth ventricle of rabbit

Abstract

The experiments were performed on 97 albino rabbits. GABA administered through injection into the fourth ventricle caused inhibition on respiratory movement or decrease in phrenic nerve discharge activity. Diazepam produced similar effects as GABA. GABA receptor antagonists, bicuculline and picrotoxin, could reverse the respiratory depressant effect of GABA. Either bicuculline or picrotoxin given alone caused an increase in respiration. These results suggest that endogeneous GABA might be an inhibitory neurotransmitter involved in the central regulation of respiration.

Keywords

GABA / respiratory depression / fourth ventricle / diazepam / bicuculline / picrotoxin

References

[1] EldridgeFL, MillhornDE. Central regulation of respiration by endogeneous neurotransmitters and neuromodulators. Ann Rev Physiol, 1981, 43121-35

[2] 1982;13: 11–4.

[3] YamadaKA, et al. . Respiratory depression produced by activation of GABA receptors in hindbrain of cat. J Appl Physiol, 1981, 511278-86

[4] SawyerCH, et al. . The rabbit diencephalon in stereotaxic coordinates. J Comp Neurol, 1954, 101801-24

[5] 1978: 208–23.

[6] EnnaSJ. GABA receptor pharmacology. Biochem Pharmacol, 1981, 30907-13

[7] AndrewsPR, JohnstonGA. GABA agonists and antagonists. Biochem Pharmacol, 1979, 282698-702

[8] CostaE, et al. . Molecular mechanisms mediating the action of diazepam on GABA receptors. Br J Psychiat, 1978, 133239-48

[9] SepinwallH, CookL. Mechanism of action of the benzodiazepines. Fed Proc, 1980, 393024-31