Systemic injections of l-DOPA (200 mg/kg) combined with a peripheral decarboxylase inhibitor (Carbidopa) produced increased motor activity and changes in regional cerebral glucose utilization similar to and different from changes seen with other dopaminergic drugs in previous studies. Similarities were an increased glucose utilization (relative optical density measurement) in the subthalamic and entopeduncular nuclei and the substantia nigra. A major difference was a suggested decreased glucose utilization in the striatum with l-DOPA treatment rather than the increases observed with apomorphine in other studies. Also, glucose utilization in the paraventricular nucleus of the hypothalamus was decreased. Finally, specific, discrete patterns were visible in motor nuclei of the l-DOPA-treated rats which were not visible with other dopaminergic drugs: the ventral posterior striatum was increased compared with the dorsal striatum and the compacta region of the substantia nigra contained unusual round spots and patterns of high-normal density and low-normal density, especially in the lateral compacta region. In one case, the density pattern in the substantia nigra was similar to the field of dopamine cell bodies and their dendrites which extend into the reticulata region. The results confirm the importance of activity in the subthalamic nucleus, globus pallidus, and entopeduncular nucleus, as well as the substantia nigra for dopaminergic drug effects either through striatal dopamine receptors or through dopamine receptors in each of these nuclei. In addition, new "functional units" in the substantia nigra were revealed. © 1982.
Warner, C., Brown, L. L., & Wolfson, L. I. (1982). l-DOPA produces regional changes in glucose utilization which form discrete anatomic patterns in motor nuclei and the hypothalamus of rats. Experimental Neurology, 78(3), 591–601. https://doi.org/10.1016/0014-4886(82)90077-2