GABA-B RECEPTOR-MEDIATED SPINAL INHIBITION

THE intravenous administration to pentobarbitone-anaesthetized cats of the GABA-B antagonists CGP 46381 and CGP 35348 blocks the longer dura tion component of the inhibition of lumbar extensor monosynaptic refle xes by tetanic stimulation of low threshold flexor primary afferent fi bres. GABA-B receptors thus appear to be associated with this inhibito ry process, in addition to bicuculline-sensitive GABA-A receptors asso ciated with shorter duration 'presynaptic' inhibition of reflexes and the depolarization of the terminals of primary afferent fibres.