Distribution of glutamic acid, aspartic acid, γ-aminobutyric acid and glycine in six areas of cat spinal cord before and after transection

Abstract

Summary 1. Determination of the concentration of glutamate, glycine, γ-aminobutyric acid, aspartate and total TCA soluble amino acids was made in six areas of the spinal cord (dorsal funiculus, dorsolateral funiculus, dorsal gray, ventral gray, ventral funiculus, and ventrolateral funiculus) from normal, sham operated cats and cats whose cords were transected 2 and 21 days earlier. 2. After 21 days there was a significant drop of glutamate and a drop of glycine in the dorsolateral funiculus. After 2 days no difference from normal data was found except a fall in the mean values of total amino acids in all areas. 3. Selective lesions of cortico-spinal or rubro-spinal tracts did not show any decrease in the aforementioned amino acids. 4. The failure of GABA concentration to decrease after cord section rules out the possibility that GABA is associated with supraspinal descending tracts.