Ascending central gustatory pathways

Abstract

The central gustatory pathways of the albino rat have been traced using a combined electrophysiological-neuroanatomical technique.Gustatory responses in the medulla were recorded in the region of the solitary nucleus which receives the seventh nerve primary afferents. Fibers traced from lesions of these recording sites did not cross as expected into the medial lemniscus, but instead travelled rostrally to terminate ipsilaterally in a small celled area dorsal and ventral to the brachium conjunctivum as it enters the pons.Since gustatory responses could be recorded in this region it represents a previously undescribed secondary "pontine taste area." Lesions of PTA result in degeneration of a bilateral ascending pathway travelling in the dorsomedial tegmentum to terminate in the classical gustatory nuclei of the thalamus. Other fibers in this pathway continue rostrally and distribute in the subthalamus, dorsolateral hypothalamus and subpallidal gray in the ventral forebrain.These findings in a mammal resemble those established nearly three quarters of a century ago by Herrick ('05) in the carp, and confirm his prediction that "broad lines of similarity [would be found1 between both the peripheral and central gustatory paths in all vertebrates."

The nucleus tractus solitarius: a portal for visceral afferent signal processing, energy status assessment and integration of their combined effects on food intake

“…The vagally transmitted effects of peripheral GLP-1R stimulation therefore involve behavioral and autonomic effector pathways that are downstream of CNS processing. [17][18][19]21,25 Structures in the ascending visceral afferent pathway, which includes nuclei of the caudal brainstem (NTS; parabrachial nucleus), hypothalamus (lateral hypothalamus; paraventricular nucleus) and basal forebrain (bed nucleus of stria terminalis; central nucleus of the amygdala), 26,27 may therefore play a role in mediating responses triggered by peripheral GLP-1R agonist treatmentA role. Similarly for the central GLP-1 system, direct central GLP-1R ligand administration activates neurons in many of the same central structures that show GLP-1-binding 23 and/or express GLP-1R mRNA.…”

Ascending Projections from the Area Postrema and the Nucleus of the Solitary Tract of Suncus Murinus

“…In the suncus, as in other mammals, the Pb is the major target for projections from the NTS, and has generally been regarded as a relay of visceral and gustatory afferents to higher levels (Norgren and Leonard, 1973;Sakai et al, 1977;Norgren, 1978;Ricardo and Koh, 1978;Beckstead et al, 1980;King, 1980;Herbert et al, 1990). Physiological studies have suggested that taste-responsive neurons are primarily located in the MPb and that viscerosensory-responsive neurons are located in the LPb (Norgren and Pfaffmann, 1975;Hermann and Rogers, 1985;Ward, 1989;Halsell and Frank, 1991).…”

Sensory regulation of dopaminergic cell activity: Phenomenology, circuitry and function

“…As well as receiving nociceptive information from the spinal cord, the PBN also receives inputs from widespread areas of the brain (Tokita et al 2009), including the rostral part of nucleus of the solitary tract (Herbert et al, 1990), a brain area involved in the processing of gustatory information (Norgren and Leonard, 1973). Gustatory processing in the PBN is normally associated with an area which includes aspects of the lateral and medial subnuclei surrounding the superior cerebellar peduncle, as well as neurons within it (Karimnamazi and Travers 1998), all of which according to our retrograde anatomical results project to the SNc and VTA.…”