The afferent connections of the posterior hypothalamic nucleus in the rat using horseradish peroxidase

Abstract

The posterior hypothalamic nucleus has been implicated as an area controlling autonomic activity. The afferent input to the nucleus will provide evidence as to its role in autonomic function. In the present study, we aimed to identify the detailed anatomical projections to the posterior hypothalamic nucleus from cortical, subcortical and brainstem structures, using the horseradish peroxidase (HRP) retrograde axonal transport technique in the rat. Subsequent to the injection of HRP into the posterior hypothalamic nucleus, extensive cell labelling was observed bilaterally in various areas of the cerebral cortex including the cingulate, frontal, parietal and insular cortices. At subcortical levels, labelled cells were observed in the medial and lateral septal nuclei, the bed nucleus of stria terminalis, and various thalamic and amygdaloid nuclei. Also axons of the vertical and horizontal limbs of the diagonal band were labelled and labelled cells were localised at the CA1 and CA3 fields of the hippocampus and the dentate gyrus. The brainstem projections were from the medial, lateral and parasolitary nuclei, the intercalated nucleus of the medulla, the sensory nuclei of the trigeminal nerve, and various reticular, vestibular, raphe and central grey nuclei. The posterior hypothalamic nucleus also received projections from the lateral and medial cerebellar nuclei and from upper cervical spinal levels. The results are discussed in relation to the involvement of the posterior hypothalamic nucleus in autonomic function and allows a better understanding of how the brain controls visceral function.

High alcohol/sucrose consumption during dark circadian phase in C57BL/6J mice: involvement of hippocampus, lateral septum and urocortin-positive cells of the Edinger-Westphal nucleus

“…Finally PH, showing lower expression of c-Fos in the alcohol/sucrose group versus the sucrose and water groups, receives projections from many of the areas identified above, including lateral septum, hippocampus and cingulate cortex (Cavdar et al 2001). …”

Cerebellar Fastigial Nuclear Inputs and Peripheral Feeding Signals Converge on Neurons in the Dorsomedial Hypothalamic Nucleus

“…However, our knowledge of the exact neuroanatomical substrates and mechanisms underlying the cerebellar feeding control has just begun. Neuroanatomical investigations have revealed that the cerebellum and hypothalamus are interconnected by bidirectional direct pathways [25][26][27][28] . Moreover, previous electrophysiological studies from our and other laboratories have demonstrated a modulation of cerebellar nuclei on the neuronal activity of hypothalamic nuclei/area, including the LHA, VMN and the paraventricular nucleus of the hypothalamus [29-31, 32, 44, 45, 48, 53] .…”

“…Among the 3 cerebellar nuclei, the fastigial nucleus (FN) is the phylogenetically oldest nucleus, holds a key position in the ultimate outputs of the spinocerebellum and has been found to modulate various gastrointestinal activities [24] . Although the underlying neural mechanisms are still poorly understood, a series of neuroanatomical studies has indicated that the bidirectional and direct cerebellar-hypothalamic circuits between cerebellum and hypothalamic nuclei/areas may mediate the cerebellar nonsomatic visceral functions [25][26][27][28] . Moreover, the neurophysiologic studies from our and other laboratories have demonstrated that the cerebellar FN functionally impinges on the feeding-related neurons in the lateral hypothalamic area (LHA) [29][30][31] .…”

“…Moreover, the neurophysiologic studies from our and other laboratories have demonstrated that the cerebellar FN functionally impinges on the feeding-related neurons in the lateral hypothalamic area (LHA) [29][30][31] . However, the neural pathway between the cerebellar FN and LHA may be only one part of the whole network of the cerebellar feeding regulation, since there are also neural projections from the cerebellar FN to the other hypothalamic nuclei including the DMN [25][26][27][28]32] . Thus, the present study particularly focused on the possible neuronal circuit between the cerebellar FN and the DMN, an autonomic structure controlling feeding and metabolism in the hypothalamus, by using extracellular recordings in vivo in rats.…”

Untitled

“…Neuroanatomical researches 8,4 by retrograde and anterograde tracings have identified direct and indirect projections from cerebellum to hypothalamus from all the three deep cerebellar nuclei and they terminate in those areas of hypothalamus which is extensively involved in autonomic activities 3,4,5,6,9,10,11,12,13 .…”