Effect of Strychnine on Dorsal Root Potentials and Amino Acid Responses in Frog Spinal Cord

The fact that the glycine-like amino acids also depolarise the primary afferents in addition to GABA has prompted this study on the action of strychnine in this system.

Abstract

STRYCHNINE blocks both the postsynaptic inhibition of spinal motoneurones and interneurones and the inhibitory action of glycine-like amino acids (such as glycine, taurine and β-alanine (BALA)) on these neurones in the cat1, 2. These observations provide strong evidence that glycine or a closely related compound mediates spinal postsynaptic inhibition1–3 . Recently, several amino acids with postsynaptic inhibitory effects (such as γ-aminobutyric acid (GABA), BALA and glycine) have been shown to depolarise the primary afferent terminals in an isolated frog spinal cord4–6, and GABA has been proposed as a possible synaptic transmitter mediating primary afferent depolarisation5, 6. However, the fact that the glycine-like amino acids also depolarise the primary afferents in addition to GABA has prompted this study on the action of strychnine in this system.