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.

Involvement of endothelins in deoxycorticosterone acetate–salt hypertension through the modulation of noradrenergic transmission in the rat posterior hypothalamus

“…The PH not only expresses ET receptors but also receives diverse afferent projections from monoaminergic inputs, originating from the adrenergic, noradrenergic and serotonergic cell groups of various brain regions, such as the anterior hypothalamus, periaqueductal grey matter, rostral raphe nuclei, parabrachial nucleus, nucleus of the solitari tract and LC (Cavdar et al . ; de Waderner, ; Kasparov & Teschemacher, ). In particular, the LC (A6 noradrenergic cell group) is closely related with the PH.…”

Modulatory Effects of Theta Burst Stimulation on Cerebellar Nonsomatic Functions

“…The cerebellum shares bidirectional connections with the hypothalamus [30–35]. Cerebello-hypothalamic axons originate from all cerebellar nuclei (fastigial, interposed, and dentate nuclei), course in the superior cerebellar peduncle, decussate, and follow the cerebello-thalamic bundle before entering the hypothalamus [36].…”

The functional anatomy of the cerebrocerebellar circuit: A review and new concepts

“…The ascending limb is the return branch of the HCC, constituted by the cerebellohypothalamic fibers . Anterograde and retrograde tract‐tracing techniques have revealed projections to the hypothalamus originating from the cerebellar nuclei; in particular, extensive hypothalamic projections have been reported from the fastigial nucleus (Çavdar et al, ; Dietrichs & Haines, ; Haines & Dietrichs, ; Haines, May, & Dietrichs, ).…”