Song SY, Zhai XM, Dai JH, Lu LL, Shan CJ, Hong J, Cao JL, Zhang LC. Novel Projections to the Cerebrospinal Fluid-Contacting Nucleus From the Subcortex and Limbic System in Rat.
Front Neuroanat 2020;
14:57. [PMID:
32973466 PMCID:
PMC7468392 DOI:
10.3389/fnana.2020.00057]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/30/2020] [Indexed: 11/29/2022] Open
Abstract
Objective: To identify the novel projections received by the cerebrospinal fluid (CSF)-contacting nucleus from the subcortex and limbic system to understand the biological functions of the nucleus.
Methods: The cholera toxin subunit B (CB), a retrograde tracer, was injected into the CSF-contacting nucleus in Sprague–Dawley rats. After 7–10 days, the surviving rats were perfused, and the whole brain and spinal cord were sliced for CB immunofluorescence detection. The CB-positive neurons in the subcortex and limbic system were observed under a fluorescence microscope, followed by 3D reconstructed with the imaris software.
Results: CB-positive neurons were found in the basal forebrain, septum, periventricular organs, preoptic area, and amygdaloid structures. Five functional areas including 46 sub-regions sent projections to the CSF-contacting nucleus. However, the projections had different densities, ranging from sparse to moderate, to dense.
Conclusions: According to the projections from the subcortex and limbic system, we hypothesize that the CSF-contacting nucleus participates in emotion, cognition, homeostasis regulation, visceral activity, pain, and addiction. In this study, we illustrate the novel projections from the subcortex and limbic system to the CSF-contacting nucleus, which underlies the diverse and complicated circuits of the nucleus in body regulations.
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