Superior colliculus involvement in the locomotor effects of ambient noise and the stimulants

Partial destruction of the superior colliculus (45%) significantly decreased the normal facilitatory effect of ambient white noise on locomotor activity levels in young rats. As recovery from surgery occurred and as test experience increased, the loss observed immediately following surgery was reduced. Presumably because of the age of the rats examined, destruction of the superior colliculus failed to potentiate the stimulant effects of d-amphetamine or methylphenidate on locomotion. These data suggest that the superior colliculus is involved in changes in general activity that result from manipulation of auditory stimuli in the environment in addition to the documented involvement of the superior colliculus in alterations of general responsivity resulting from manipulations of visual stimuli in the environment. Moreover, the superior colliculus is implicated in maintaining both excitatory and inhibitory changes in response to the environment of the organism.