Journal of Neuroscience, Vol 1, 285-291, Copyright © 1981 by Society for Neuroscience
Metabolic effects of unilateral lesion of the substantia nigra
GF Wooten and RC Collins
Regional brain glucose utilization following unilateral lesion of the
substantia nigra in rat was studied by [14C]-2-deoxyglucose
autoradiography. Substantia nigra lesions were performed by perinigral
injections of 6-hydroxydopamine (6-OHDA) . HBr, 6 microgram, in rats
pretreated 30 min earlier with desmethylimipramine (DMI), 25 mg/kg,
subcutaneously. The lesion produced extensive destruction of the
ipsilateral substantia nigra pars compacta and a greater than 99% reduction
in dopamine concentration in the ipsilateral striatum. Pretreatment with
DMI prevented any reduction in the concentration of norepinephrine in
ipsilateral forebrain structures. Glucose utilization was increased in the
ipsilateral globus pallidus at 11, 21, 53, and 104 days after substantia
nigra lesion with the largest increase (about 140% of control) occurring at
21 days post-lesion. In addition, glucose utilization in ipsilateral
lateral habenular nucleus was increased at each of the above time points.
No changes in glucose utilization were noted in frontal cortex, striatum,
subthalamic nucleus, entopeduncularis, or ventral tier nuclei of the
thalamus. These results suggest that lesion of the substantia nigra with
depletion of striatal dopamine content results in disinhibition of some
striatal, and perhaps olfactory cortical, efferents producing increased
metabolism and glucose utilization in terminal fields within the globus
pallidus and lateral habenular nucleus.
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