Cycloserine (CS)

Cycloserine is an antibiotic effective against Mycobacterium tuberculosis. Since the discovery that cycloserine is able to penetrate into the central nervous system, numerous studies have been conducted to assess the efficacy of cycloserine for psychiatric disorders. It has been found to be effective in the treatment of some neurological disorders, due to its effect as a selective partial agonist of the N-methyl-D-aspartic acid (NMDA) glutamatergic receptors found in the basolateral nucleus of the amygdala. Specifically, cycloserine affects the glycine-binding sites which are important for opening these NMDA channels. Cycloserine works as an antibiotic by inhibiting cell-wall biosynthesis in bacteria. D-Cycloserine, when used in conjunction with exposure-based cognitive behavior therapy, helps with fear extinction in an array of anxiety- and stress-inducing disorders.