Pentylenetetrazol: An antagonist of gaba at primary afferents of the isolated frog spinal cord

Abstract

In the isolated frog spinal cord, pentylenetetrazole in concentrations over 10 −2 M, selectively abolished dorsal root potential evoked by ventral root stimulation and attenuated dorsal root potential generated by stimulation of adjacent dorsal root. In the same concentration pentylenetetrazole differentially affected some neutral amino acid responses without interfering with the glutamate response. On the dorsal root, β-alanine and taurine depolarizing responses were abolished and the γ-aminobutyric acid response was attenuated. In contrast to other convulsants, pentylenetetrazole was found to antagonize the depolarizing component of neutral amino acid responses of frog motoneurones.