The use of convulsants in studying possible functions of amino acids in the toad spinal cord

Abstract 1. 1. Amino acids and convulsants were applied topically to the toad spinal cord. 2. 2. l -Glutamic acid produced depolarizations in dorsal and ventral roots. 3. 3. GABA produced depolarizations in dorsal roots and both depolarizations and hyperpolarizations in ventral roots. 4. 4. β-Alanine and glycine were generally comparable to GABA but sometimes caused hyperpolarizations in dorsal roots. 5. 5. Picrotoxin reduced the depolarizing effects of l -glutamic acid and GABA on dorsal roots, and depressed dorsal root reflexes. 6. 6. Strychnine blocked the hyperpolarizing effects of β-alanine and glycine, but not of GABA, on ventral roots.