Occurrence of a Porphyrin Pigment in Streptomycetes

Abstract

Injection of more than ten mouse lethal doses of tetanus toxin into cat's motor cortex produces seizures accompanied by cortical electrical convulsive discharges. During the hours preceding onset of large seizures, "antidromic" inhibition of evoked cortical activity is reduced. The similarity of these effects to those observed in spinal cord suggests operation of similar inhibitory transmitters in the two parts of the central nervous system.