Participation of the reticular formation of the mesencephalon in the development of habituation to visceral influences.

In experiments on cats anesthetized with chloralose and immobilized with flaxedil, the influence of the reticular formation (RF) of the mesencephalon on the development of habituation of evoked potentials (EP) in the cerebral cortex (CC) to repeated stimulation of the splanchnic nerve was studied. It was established that high frequency stimulation of the RF (100 counts/sec) for 15 sec before testing for habituation to visceral stimulation inhibited the amplitude of the EP and shortened the time of development of habituation to repeated stimulation of the splanchnic nerve. Low-frequency stimulation of the RF (1 pulse/sec), applied during the development of habituation, restored the amplitude of the EP to the initial level. The turnoff of the activity of the RF by intravenously injected chlorpromazine (3-6 mg/kg) was accompanied by an acceleration of the development of habituation of evoked potentials in the associative region of the cortex. The participation of the RF in processes of habituation and dehabituation is discussed.