Tags

Type your tag names separated by a space and hit enter

Cellular basis for the effects of substance P in the periaqueductal gray and dorsal raphe nucleus.
J Comp Neurol. 2002 May 20; 447(1):82-97.JC

Abstract

Substance P (SP) is known to act at supraspinal sites to influence pain sensitivity as well as to promote anxiety. The effects of SP could be mediated in part by actions in the periaqueductal gray (PAG) and the dorsal raphe nucleus (DRN), adjoining mesencephalic cell groups that are strategically positioned to influence both nociception and mood. Previous studies have indicated that SP regulates both enkephalin and serotonin neurotransmission in these brain regions. To determine the mechanism underlying the effects of SP in the PAG and DRN, the distribution of the principal receptor for SP, the neurokinin 1 (NK1) receptor, was examined with respect to other neurotransmitter markers. PAG neurons that had NK1 receptor immunolabeling were interdigitated with and received contacts from enkephalin-containing neurons. However, only a few (16/144; 11%) neurons with NK1 receptor also contained enkephalin immunoreactivity after colchicine treatment. In the DRN, dendrites containing NK1 receptor were selectively distributed in the dorsomedial subdivision. The majority (132/137; 96%) of these dendrites did not contain immunoreactivity for the serotonin-synthesizing enzyme tryptophan hydroxylase. In contrast, neuronal profiles with NK1 receptor in both the PAG and the DRN often contained immunolabeling for glutamate. Light and electron microscopic examination revealed that 48-65% of cell bodies and dendrites with NK1 receptor were dually immunolabeled for glutamate. These data suggest that SP directly acts primarily on glutamatergic neurons in the PAG and DRN. To a lesser extent, enkephalin-containing neurons may be targeted. Through these actions, it may subsequently influence activity of larger populations of neurons containing enkephalin as well as serotonin. This circuitry could contribute to, as well as coordinate, effects of SP on pain perception and mood.

Authors+Show Affiliations

Children's Hospital of Philadelphia, Joseph Stokes Research Institute, 402 Abramson Research Center, Philadelphia, Pennsylvania 19104, USA. commonk@yahoo.comNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

11967897

Citation

Commons, Kathryn G., and Rita J. Valentino. "Cellular Basis for the Effects of Substance P in the Periaqueductal Gray and Dorsal Raphe Nucleus." The Journal of Comparative Neurology, vol. 447, no. 1, 2002, pp. 82-97.
Commons KG, Valentino RJ. Cellular basis for the effects of substance P in the periaqueductal gray and dorsal raphe nucleus. J Comp Neurol. 2002;447(1):82-97.
Commons, K. G., & Valentino, R. J. (2002). Cellular basis for the effects of substance P in the periaqueductal gray and dorsal raphe nucleus. The Journal of Comparative Neurology, 447(1), 82-97.
Commons KG, Valentino RJ. Cellular Basis for the Effects of Substance P in the Periaqueductal Gray and Dorsal Raphe Nucleus. J Comp Neurol. 2002 May 20;447(1):82-97. PubMed PMID: 11967897.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Cellular basis for the effects of substance P in the periaqueductal gray and dorsal raphe nucleus. AU - Commons,Kathryn G, AU - Valentino,Rita J, PY - 2002/4/23/pubmed PY - 2002/6/27/medline PY - 2002/4/23/entrez SP - 82 EP - 97 JF - The Journal of comparative neurology JO - J. Comp. Neurol. VL - 447 IS - 1 N2 - Substance P (SP) is known to act at supraspinal sites to influence pain sensitivity as well as to promote anxiety. The effects of SP could be mediated in part by actions in the periaqueductal gray (PAG) and the dorsal raphe nucleus (DRN), adjoining mesencephalic cell groups that are strategically positioned to influence both nociception and mood. Previous studies have indicated that SP regulates both enkephalin and serotonin neurotransmission in these brain regions. To determine the mechanism underlying the effects of SP in the PAG and DRN, the distribution of the principal receptor for SP, the neurokinin 1 (NK1) receptor, was examined with respect to other neurotransmitter markers. PAG neurons that had NK1 receptor immunolabeling were interdigitated with and received contacts from enkephalin-containing neurons. However, only a few (16/144; 11%) neurons with NK1 receptor also contained enkephalin immunoreactivity after colchicine treatment. In the DRN, dendrites containing NK1 receptor were selectively distributed in the dorsomedial subdivision. The majority (132/137; 96%) of these dendrites did not contain immunoreactivity for the serotonin-synthesizing enzyme tryptophan hydroxylase. In contrast, neuronal profiles with NK1 receptor in both the PAG and the DRN often contained immunolabeling for glutamate. Light and electron microscopic examination revealed that 48-65% of cell bodies and dendrites with NK1 receptor were dually immunolabeled for glutamate. These data suggest that SP directly acts primarily on glutamatergic neurons in the PAG and DRN. To a lesser extent, enkephalin-containing neurons may be targeted. Through these actions, it may subsequently influence activity of larger populations of neurons containing enkephalin as well as serotonin. This circuitry could contribute to, as well as coordinate, effects of SP on pain perception and mood. SN - 0021-9967 UR - https://www.unboundmedicine.com/medline/citation/11967897/Cellular_basis_for_the_effects_of_substance_P_in_the_periaqueductal_gray_and_dorsal_raphe_nucleus_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0021-9967&date=2002&volume=447&issue=1&spage=82 DB - PRIME DP - Unbound Medicine ER -