[Effect of strychnine and picrotoxin on the development of habituation in the visceral analyzer]

Effects of strychnine and picrotoxin on habituation of cortical potentials evoked by repeated stimulation of the splanchnic nerve were studied in anesthetized and immobilized cats. I. v. administration of strychnine (o.1 mg/kg) or picrotoxin (0.4 mg/kg) did not alter the decrement in evoked potentials. Larger doses of strychnine (0.3 or 0.6 mg/kg) and picrotoxin (0.8 or 2.0 mg/kg) did not block the habituation effects either. Picrotoxin applied to 2nd somatosensory area of the cortex effected amplitude of the negative component of the evoked potentials. Possible mechanisms of the habituation process are discussed.