Parallel preoptic pathways for thermoregulation.

Full Abstract

Sympathetic premotor neurons in the rostral medullary raphe (RMR) regulate heat conservation by tail artery vasoconstriction and brown adipose tissue thermogenesis. These neurons are a critical relay in the pathway that increases body temperature. However, the origins of the inputs that activate the RMR during cold exposure have not been definitively identified. We investigated the afferents to the RMR that were activated during cold by examining Fos expression in retrogradely labeled neurons after injection of cholera toxin B subunit (CTb) in the RMR. These experiments identified a cluster of Fos-positive neurons in the dorsomedial hypothalamic nucleus and dorsal hypothalamic area (DMH/DHA) with projections to the RMR that may mediate cold-induced elevation of body temperature. Also, neurons in the median preoptic nucleus (MnPO) and dorsolateral preoptic area (DLPO) and in the A7 noradrenergic cell group were retrogradely labeled but lacked Fos expression, suggesting that they may inhibit the RMR. To investigate whether individual or common preoptic neurons project to the RMR and DMH/DHA, we injected CTb into the RMR and Fluorogold into the DMH/DHA. We found that projections from the DLPO and MnPO to the RMR and DMH/DHA emerge from largely separate neuronal populations, indicating they may be differentially regulated. Combined cell-specific lesions of MnPO and DLPO, but not lesions of either one alone, caused baseline hyperthermia. Our data suggest that the MnPO and DLPO provide parallel inhibitory pathways that tonically inhibit the DMH/DHA and the RMR at baseline, and that hyperthermia requires the release of this inhibition from both nuclei.

Author information

Author/s: Yoshida, Kyoko (K); Li, Xiaodong (X); Cano, Georgina (G); Lazarus, Michael (M); Saper, Clifford B (CB);

Affiliation: Department of Neurology, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA.

Grants: NS33987 (Agency:NINDS NIH HHS)

Journal and publication information

Publication Type: Journal Article; Research Support, U.S. Gov't, P.H.S.

Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience (J Neurosci), published in United States. (Language: eng)

Reference: 2009-Sep; vol 29 (issue 38) : pp 11954-64

Dates: Created 2009/09/24; Completed 2009/10/09;

PMID: 19776281, status: MEDLINE (last retrieval date: 10/9/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Animals
Body Temperature
Body Temperature Regulation - physiology
Catecholamines - metabolism
Cholera Toxin
Cold Temperature
Fever - chemically induced; physiopathology
Hypothalamus - physiology
Lipopolysaccharides
Male

Male
Neural Pathways - injuries; physiology
Neurons - physiology
Norepinephrine - metabolism
Preoptic Area - injuries; physiology
Proto-Oncogene Proteins c-fos - metabolism
Raphe Nuclei - physiology
Rats
Rats, Sprague-Dawley
Time Factors

Associated Chemicals: Catecholamines (0) ; Lipopolysaccharides (0) ; Proto-Oncogene Proteins c-fos (0) ; Norepinephrine (51-41-2) ; Cholera Toxin (9012-63-9)

These are the highest related articles currently in the database: