Sentence:  In other studies , loss of differentiation in previously established conditioned reflexes resulted from repeated convulsive ( <WSD>metrazol</WSD> ) treatments , suggesting a fundamental disturbance in the balance between excitatory and inhibitory cerebral processes . 
Meaning of the word marked with <WSD> tags:  a drug used as a circulatory and respiratory stimulant; larger doses cause convulsions in shock therapy; Metrazol is a trademark