Increased subcortical and laminar cortical 2-deoxy[ 14C]glucose uptake during cerebellar stimulation

Abstract

2-Deoxy[ 14C]glucose (2DG) uptake was mapped in brains of conscious rats during cerebellar hemisphere electrical stimulation and compared with sham-operated controls. The 2DG uptake increased bilaterally in cerebellar cortex and deep nuclei, the largest increases being ipsilateral to the stimulating electrode. Structures which increased 2DG uptake bilaterally but had larger contralateral increases included the red nucleus, inferior olive, zona incerta, substantia nigra, globus pallidus, deep mesencephalic nucleus, habenula, reticular tegmental nucleus of the pons, ventroanterolateral and ventromedial nuclei of thalamus, several other thalamic nuclei, and motor-somatosensory cortex. Most of these structures receive efferent fibers from cerebellar nuclei. Cerebellar stimulation produced two bands of 2DG uptake bilaterally in rat motor-somatosensory neocortical laminae IV and Vc-VIa. Shamoperated controls had one band of 2DG uptake in neocortical lamina IV. We postulate that cerebellar stimulation increased 2DG uptake polysynaptically in lamina Vc-VIa by the following pathway: Purkinje cells → deep cerebellar nuclei → ventrolateral and/or ventromedial nuclei of thalamus → lamina Vc-VIa of neocortex. Activation of these cortical laminae could affect cortical seizure foci.