Autonomic response to cerebellar stimulation in the decorticate cat

The cerebral cortex and basal nuclei were removed under intravenous thiopental anesthesia in 63 cats. Beginning 2–3 hr after the final injection of thiopental, the cerebellar cortex was stimulated with bipolar stainless steel electrodes, with isolation of current to the cortex immediately beneath the electrodes. Parameters of the biphasic square wave stimulus were: current density 1.0–3.71 ma/mm2, pulse duration 1.0 msec, frequency 200 cycle/sec, train duration 7–15 sec. Elevation and depression of bladder pressure, constriction and dilatation of the pupil, elevation of blood pressure, and retraction of the nictitating membrane were obtained at P values of <10–7 to <10–10. Responsive areas included lobus simplex, ansiform lobule, paramedian lobule and vermis.

Autonomic response to chronic electrode stimulation of cerebellum

The cerebellum was stimulated with implanted chronic concentric stainless steel electrodes in ten cats, with isolation of current to the cortex immediately beneath the electrodes. Stimulus parameters were: current density 0.5–2.55 ma/mm2, pulse duration 1–2 msec., frequency 100 cycle/sec, stimulus train duration 10–15 sec. Elevation of bladder pressure, pupillary dilatation, and pupillary constriction were obtained at P values of 10–7–10–10; depression of bladder pressure at P < 10–5. Responsive areas included ansiform lobule and vermis.