Deficits in visual discrimination performance following neglect-producing unilateral lateral hypothalamic lesions in the albino rat☆

A psychomotor stimulant theory of addiction.

“…There are several reasons to characterize the effects of these substances as something more than simple motoric effects. First, lesions or pharmacological blockade of the dopamine systems cause a form of sensorimotor neglect rather than a simple motoric or sensory impairment (Ackil & Frommer, 1984; Carli, Evendon, & Robbins, 1985; Hoyman, 1979; Hoyman, Weese, & Frommer, 1979; Marshall, 1978). Although lesions usually cause total akinesia when all brain dopamine is depleted (Stricker & Zigmond, 1976), it can be seen that certain movements are possible though they are not made in response to the environmental stimuli that normally elicit them (Wolgin, Cytawa, & Teitelbaum, 1976).…”

“…The deficit is, however, clearly one of sensorimotor integration rather than sensory or motor function per se. The animals can demonstrate both contralateral sensory and contralateral motoric capability in selected tests; what the animals consistently fail to do is make contralateral responses to contralateral stimuli (Ackil & Frommer, 1984; Carli et al, 1985; Hoyman et al, 1979; Turner, 1973). The fact that left-lesioned rats can make right-paw responses to left-side stimuli and can make left-paw responses to right-side stimuli makes it clear that the deficit is not a simple sensory or simple motor disability.…”

Experimental Models on Effects of Psychostimulants

“…Lesions of the central dopaminergic systems cause a form of sensorimotor neglect (Ackil & Frommer, 1984;Carli, Evenden, & Robbins, 1985;Hoyman, Weese, & Frommer, 1979). Similarly, pharmacological blockade of the dopamine system reduces motivation for lever pressing or running an alleyway while their motor abilities remain intact (Fouriezos, Hansson, & Wise, 1978;Fouriezos & Wise, 1976;Wise, Spindler, deWit, & Gerberg, 1978).…”

“…When the lesions are unilateral, animals generally fail to orient to visual, olfactory, or tactile stimuli contralateral to the side of lesion. Animals fail to make contralateral responses to stimuli, while they have perfect contralateral sensory or motor capability supporting a disturbance of sensorimotor integration (Ackil & Frommer, 1984).…”