Organization of cerebral cortical afferent systems in the rat. II. Hypothalamocortical projections

摘要: The organization of hypothalamic projections to the cerebral cortex in rat has been studied using retrograde and anterograde tracer methods. Four separate populations neurons, which constitute a major source diffuse cortical innervation, were identified: Tuberal lateral (LHAt) neurons innervate tend cluster perifornical region, zona incerta, along medial edge peduncle, at levels roughly coextensive with ventromedial nucleus. Most these project ipsilateral cortex; small percentage contralateral cortex, but this varies among terminal fields. are organized topographic medial-to-lateral relationship respect their Field Forel (FF) primarily frontal hemisphere, located just ventral lemniscus, level basal thalamic more laterally placed frontal, insular perirhinal around mammillothalamic tract, frontopolar, prelimbic, infralimbic, anterior cingulate cortex. Posterior (LHAp) form dense spanning hypothalamus, from peduncle posterior area premammillary levels, extending into supramammillary nucleus adjacent tegmental area. LHAp entire predominantly on side. Populations projecting different target areas show considerable spatial overlap, computer plots centers demonstrate strict Tuberomammillary (TMN) sheet ventrolateral surface hypothalamus. About twice as many TMN ipsilateral, compared hemisphere; it is not known whether single both hemispheres. No projection apparent. Injections different-colored fluorescent dyes various that general have rather restricted Only occasional found, LHAt, double labeled by injections cytoarchitectonic areas.(ABSTRACT TRUNCATED AT 400 WORDS)