Self-stimulation at the lateral hypothalamus and locus coeruleus after specific unilateral lesions of the dopamine system.
A group of rats was trained to press levers for electrical stimulation from bipolar electrodes aimed at the lateral hypothalamus (LH), and another group was trained to self-stimulate from electrodes in the locus coeruleus (LC). All rats in both groups were subjected to unilateral injections of 6-hydroxydopamine into the substantia nigra and midbrain ventral tegmentum. The lesions produced profound depletions of dopamine from the ipsilateral frontal cortex, nucleus accumbens/olfactory tubercle, and corpus striatum. Pretreatment with desmethylimipramine prevented loss of noradrenaline in excess of that caused by electrode implantation. The destruction of the dopamine projections produced a persistent and pronounced deficit in intracranial self-stimulation from ipsilateral electrodes in both the LH and LC groups, but only transient effects on self-stimulation from contralateral electrodes at these sites. These results suggest that an intact dopamine system is required for the expression of self-stimulation behaviour.
D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D005625:Frontal Lobe / Q000378:metabolism; D006892:Hydroxydopamines / Q000494:pharmacology; D007031:Hypothalamus / Q000502:physiology*; D008125:Locus Coeruleus / Q000502:physiology*; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D009714:Nucleus Accumbens / Q000378:metabolism; D009830:Olfactory Bulb / Q000378:metabolism; D051381:Rats; D011954:Receptors, Dopamine / Q000502:physiology*; D012653:Self Stimulation / Q000502:physiology*; D013378:Substantia Nigra / Q000187:drug effects / Q000502:physiology; D013681:Tegmentum Mesencephali / Q000187:drug effects / Q000502:physiology
D006892:Hydroxydopamines; D011954:Receptors, Dopamine; D004298:Dopamine; D009638:Norepinephrine