Topography of basal glucose utilization in rat thalamus and hypothalamus determined with (1-14C)-glucose

Summary High resolution autoradiography was used to study the basal pattern of glucose-utilization in the rat thalamus and hypothalamus. Rats were injected via chronic jugular catheter with (1-¹⁴C)-glucose and sacrificed 30 min later. The high resolution thaw-mount autoradiographic procedure, using 4 m frozen sections and nuclear emulsion, permited discrimination of regional variations in glucose-utilization that have not yet been described. Quantitative data were obtained by means of digital image analysis and computerized densitometry. In the thalamus, high activity was present in the anterodorsal, anteroventral, laterodorsal and reticular nuclei, while low activity was found in the mediodorsal and paraventricular nuclei. The autoradiographic pattern of glucose utilization in the thalamus corresponds largely to classical cytoarchitectonic subdivisions. In the hypothalamus, the median eminence, arcuate nucleus, and periventricular nucleus showed the lowest activity, whereas certain parts of the lateral hypothalamus appeared high. Very high activity was present in mammillary nuclei. The described detailed anatomical data of glucose-utilization may provide insights into the functional circuitry of thalamic and hypothalamic systems and serve as a baseline from which experimental manipulations can be assessed.Abbreviations ac anterior commisure - AD anterodorsal thalamic nucleus - AHy anterior hypothalamic area - APT anterior pretectal area - Arc arcuate hypothalamic nucleus - AV anteroventral thalamic nucleus - BST bed nucleus of the stria terminalis - ch choroid plexus - CM central medial thalamic nucleus - CL centrolateral thalamic nucleus - cp cerebral peduncle - Dk nucleus of Darkschewitsch - DLG dorsal lateral geniculate nucleus - EP entopeduncular nucleus - F nucleus of the fields of Forel - f fornix - fr fasciculus retroflexus - Gem gemini hypothalamic nucleus - HDB nucleus of the horizontal limb of the diagonal band - IAM interanteromedial thalamic nucleus - ic internal capsule - LD laterodorsal thalamic nucleus - LH lateral hypothalamic area - LHb lateral habenular nucleus - LM lateral mammillary nucleus - LP lateral posterior thalamic nucleus - MD mediodorsal thalamic nucleus - m central part - c central part - l lateral part - ME median eminence - MGD medial geniculate nucleus, dorsal part - MGV medial geniculate nucleus, ventral part - MHb medial habenular nucleus - ML medial mammillary nucleus, lateral part - ml medial lemniscus - MM medial mammillary nucleus, medial part - MP medial mammillary nucleus, posterior part - MPO medial preoptic area - MS medial septal nucleus - MT medial terminal nucleus of the accessory optic tract - mt mammillothalamic tract - mtg mammillotegmental tract - ox optic chiasm - pc posterior commissure - Pe periventricular hypothalamic nucleus - PF parafascicular thalamic nucleus - PMD premammillary nucleus, dorsal part - Po posterior thalamic nuclear group - PT paratenial thalamic nucleus - PV paraventricular thalamic nucleus - PVN paraventricular hypothalamic nucleus - RCh retrochiasmatic area - Rh rhomboid thalamic nucleus - Rt reticular thalamic nucleus - SCh suprachiasmatic nucleus - sm stria medullaris of the thalamus - SNC substantia nigra, compact part - SNR substantia nigra, reticular part - SPF subparafascicular thalamic nucleus - st stria terminalis - STH subthalamic nucleus - VL ventrolateral thalamic nucleus - VLG ventral lateral geniculate nucleus - m magnocellular part - p parvocellular part - VMH ventromedial hypothalamic nucleus - VPL ventral posterolateral thalamic nucleus - VPM ventral posteromedial thalamic nucleus - ZI zona incerta