Afferent projections to the periaqueductal gray in the rabbit

Meller, Stephen T.; Dennis, Barbara J.

doi:10.1016/0306-4522(86)90308-8

Cited by 116 publications

(36 citation statements)

References 172 publications

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“…The output of the PMd has not been examined previously by anterograde tracing methods; and of all the projections described here, only that to the central gray has been reported in retrograde tracing experiments (18)(19)(20)(21). The latter indicate that the PMd contains the highest density of retrograde labeling in the hypothalamus following tracer injections in the central gray.…”

Section: Discussionmentioning

confidence: 69%

The dorsal premammillary nucleus: an unusual component of the mammillary body.

Canteras

Swanson

1992

Proc. Natl. Acad. Sci. U.S.A.

145

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The results of anterograde and retrograde axonal transport experiments in the rat indicate that the dorsal premmmilary nucleus (PMd) gives rise to a branched pathway ending in the anterior thalamic group and brainstem, like the medial and lateral mammillary nuclei. However, unlike these nuclei, the ascending PMd projection courses through and to the anterior hypothalamic nucleus, and the descending PMd projection ends in the periaqueductal gray, superior colliculus, and adjacent parts of the reticular formation. Also unlike the traditional mammillary nuclei, the PMd does not receive a direct input from the columns of the fornix; instead, it receives a bilateral input from the anterior hypothalamic nucleus, which in turn receives inputs from areas related to the prefrontal cortex, amygdala, and hippocampus. The results provide interesting perspectives on the organization of medial hypothalamic circuits underlying the goal-oriented behaviors associated with hunger, thirst, and reproduction.The medial zone of the hypothalamus contains a longitudinally arranged series of well-defined nuclei that play a critical role in expression of goal-oriented behaviors, ensuring survival of the individual (homeostasis) as well as the species (reproduction) (1). And while the input/output relationships of the medial zone are complex, the nuclei are dominated by afferents from limbic regions ofthe telencephalon that clearly divide them into two groups: caudal (mammillary) and rostral. The mammillary group receives a major input from the postcommissural fornix, which arises in the subicular complex of the hippocampal formation (2-5) and is a major component of the classical "Papez circuit" (6), which is now thought to play a role in learning and memory (7-10). In contrast, the rostral group of medial zone nuclei receives massive inputs from the amygdala (11), ventral subiculum (3,11), and lateral septal nucleus (12) that are dominated by olfactory information and play a role in expression of ingestive and reproductive behaviors (1). The separation of medial hypothalamic nuclei into rostral and caudal groups is also strengthened by evidence that few pathways appear to interconnect the two, and most ascending inputs from the brainstem end in one or the other (1). Thus, the neuroanatomical evidence indicates that information processed in the rostral nuclei of the medial hypothalamus has no major direct access to the Papez circuit.While reexamining the projections of the medial hypothalamic nuclei by the Phaseolus vulgaris agglutinin L (leukoagglutinin) subunit (PHA-L) method (13), we found that a previously unexplored cell group, the dorsal premammillary nucleus (PMd), projects to the anterior thalamic nuclei and to the upper brainstem, much like the medial and lateral mammillary nuclei, but appears to receive its major input from the anterior hypothalamic nucleus (in the rostral medial group) rather than from the postcommissural fornix (4, 14). These observations form the basis of the work reported here, which suggests that t...

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Section: Discussionmentioning

confidence: 69%

The dorsal premammillary nucleus: an unusual component of the mammillary body.

Canteras

Swanson

1992

Proc. Natl. Acad. Sci. U.S.A.

145

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“…The dorsolateral gray is known to respond to saccade activity (Kase et al, 1986) and receive fastigial nucleus input (Hirai et al, 1982). Previous studies (Beitz, 1982;Meller and Dennis, 1986) found that the hypothalamus and cuneate nuclei also project strongly to the dorsolateral area. Holstege and Cowie (1990) proposed that the dorsolateral periaqueductal gray influences the other periaqueductal subnuclei and the limbit system to help control appropriate behavioral responses to novel environmental conditions, which might involve integrating vestibular and visual inputs.…”

Section: Arsanilate Labyrinthectomymentioning

confidence: 99%

Fos-defined activity in rat brainstem following centripetal acceleration

1992

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To identify rat brainstem nuclei involved in the initial, shortterm response to a change in gravito-inertial force, adult Long-Evans rats were rotated in the horizontal plane for 90 min in complete darkness after they were eccentrically positioned off the axis of rotation (off-axis) causing a centripetal acceleration of 2 g. Neural activation was defined by the brainstem distribution of the c-fos primary response gene protein, Fos, using immunohistochemistry.The Fos labeling in off-axis animals was compared with that of control animals who were rotated on the axis of rotation (on-axis) with no centripetal acceleration, or who were restrained but not rotated. In the off-axis animals there was a significant labeling of neurons: in the inferior, medial, and y-group subnuclei of the vestibular complex; in subnuclei of the inferior olive, especially the dorsomedial cell column; in midbrain nuclei, including the interstitial nucleus of Cajal, nucleus of Darkschewitsch, Edinger-Westphal nucleus, and dorsolateral periaqueductal gray; in autonomic centers including the solitary nucleus, area postrema, and locus coeruleus; and in reticular nuclei including the lateral reticular nucleus and the lateral parabrachial nucleus. Also, there was greater Fos expression in the dorsomedial cell column, the principal inferior olive subnuclei, inferior vestibular nucleus, the dorsolateral central gray, and the locus coeruleus in animals who had their heads restrained compared to animals whose heads were not restrained. As one control, the vestibular neuroepithelium was destroyed by injecting sodium arsanilate into the middle ear, bilaterally. This resulted in a complete lack of Fos labeling in the vestibular nuclei and the inferior olive, and a significant reduction in labeling in other nuclei in the off-axis condition, indicating that these nuclei have a significant labyrinth-sensitive component to their Fos labeling. The data indicate that several novel brainstem regions, including the dorsomedial cell column of the inferior olive and the periaqueductal gray, as well as more traditional brainstem nuclei including vestibular and oculomotor related nuclei, respond to otolith activation during a sustained centripetal acceleration.Received Mar. 2, 1992; revised June 5, 1992; accepted June 12, 1992. We thank Jaw-Hem Lee and Huna Nauven for their sutmortine work in our labs. This work is made possible by a griduate student researchepprogram fellowship and NIH Grants DC01086, NS19208, DC001 10, DE06682, and DA06687.Correspondence should be addressed to Alvin J. Normal coordination of body movement and posture depends upon an accurate spatial reference. The otolith organs of the vestibular labyrinth are sensitive to the direction and magnitude of the earth's gravity and could provide a reference for integrating vestibular, visual, and somatosensory information to help control movement. When a sustained change in the gravitoinertial force occurs (e.g., from a novel linear motion, in a microgravity environment, or as a result of inner ear...

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“…The lateral PAG region, which is highly implicated in vocalization, receives projections from the ipsilateral medial and bilateral ventrolateral NTS in the cat (Bandler and Tork, 1987). In the rat, it receives bilateral projections from the medial and caudal commissural subnuclei of the NTS (Herbert and Saper, 1992), whereas in the rabbit, projections are from the contralateral NTS to the ventrolateral, lateral, and dorsal regions of the PAG (Mellor and Dennis, 1986). Interestingly, the subnuclei of the NTS that connect to the PAG are not the major laryngeal afferent termination zones.…”

Section: Potential Afferent Pathways Inducing Fos In the Periaqueductmentioning

confidence: 97%

“…It is possible that laryngeal afferent information reaches the PAG by polysynaptic connections through the NTS. Based on neuroanatomical studies, the NTS is reciprocally connected with the PAG in the cat (Yoshida et al, 1985;Bandler and Tork, 1987), rat (Herbert and Saper, 1992;Cameron et al, 1995), and rabbit (Mellor and Dennis, 1986). The tracers used in the previous studies, such as horseradish peroxidase (Kalia and Mesulam, 1980;Nomura and Mizuno, 1983;Mrini and Jean, 1995), cannot be used to localize second or higher order neurons receiving laryngeal afferent input.…”

mentioning

confidence: 96%