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5-hydroxytryptamine 1A (5-HT1A) but not 5-HT3 receptor is involved in mediating the nucleus submedius 5-HT-evoked antinociception in the rat.
Brain Res. 2005 Jun 07; 1046(1-2):38-44.BR

Abstract

Our previous studies have indicated that the thalamic nucleus submedius (Sm) is involved in modulation of nociception as part of an ascending component of an endogenous analgesic system consisting of spinal cord-Sm-ventrolateral orbital cortex (VLO)-periaqueductal gray (PAG)-spinal cord loop. Microinjection of 5-hydroxytryptamine (5-HT) into Sm produces antinociception and this effect is blocked by 5-HT(2) receptor antagonist. The aim of the present study was to examine whether the 5-HT(1) and 5-HT(3) receptors were also involved in the Sm 5-HT-evoked antinociception. Nociception was assessed in lightly anesthetized rats with radiant-heat-evoked tail flick (TF). 5-HT(1A) and 5-HT(3) receptor antagonists were microinjected into the Sm alone or in combination with a microinjection of 5-HT into the same Sm site. 5-HT(1A) receptor antagonist p-MPPI (0.87 nmol) facilitated the TF reflex; a lower dose (0.43 nmol) of p-MPPI significantly attenuated the Sm 5-HT-evoked inhibition of TF reflex. Microinjection of the 5-HT(3) receptor antagonist LY-278,584 (12 nmol) had no effect either on the TF reflex or on the Sm 5-HT-evoked inhibition. These results suggest that 5-HT(1A) receptor but not 5-HT(3) receptor is involved in mediating the 5-HT-evoked antinociception. Possible mechanisms of Sm 5-HT-induced descending antinociception are discussed.

Authors+Show Affiliations

Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Department of Physiology, School of Medicine, Xi'an Jiaotong University, Shaanxi, People's Republic of China.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15869749

Citation

Xiao, Dan-Qin, et al. "5-hydroxytryptamine 1A (5-HT1A) but Not 5-HT3 Receptor Is Involved in Mediating the Nucleus Submedius 5-HT-evoked Antinociception in the Rat." Brain Research, vol. 1046, no. 1-2, 2005, pp. 38-44.
Xiao DQ, Zhu JX, Tang JS, et al. 5-hydroxytryptamine 1A (5-HT1A) but not 5-HT3 receptor is involved in mediating the nucleus submedius 5-HT-evoked antinociception in the rat. Brain Res. 2005;1046(1-2):38-44.
Xiao, D. Q., Zhu, J. X., Tang, J. S., & Jia, H. (2005). 5-hydroxytryptamine 1A (5-HT1A) but not 5-HT3 receptor is involved in mediating the nucleus submedius 5-HT-evoked antinociception in the rat. Brain Research, 1046(1-2), 38-44.
Xiao DQ, et al. 5-hydroxytryptamine 1A (5-HT1A) but Not 5-HT3 Receptor Is Involved in Mediating the Nucleus Submedius 5-HT-evoked Antinociception in the Rat. Brain Res. 2005 Jun 7;1046(1-2):38-44. PubMed PMID: 15869749.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - 5-hydroxytryptamine 1A (5-HT1A) but not 5-HT3 receptor is involved in mediating the nucleus submedius 5-HT-evoked antinociception in the rat. AU - Xiao,Dan-Qin, AU - Zhu,Juan-Xia, AU - Tang,Jing-Shi, AU - Jia,Hong, PY - 2004/10/09/received PY - 2005/03/12/revised PY - 2005/03/15/accepted PY - 2005/5/5/pubmed PY - 2005/9/28/medline PY - 2005/5/5/entrez SP - 38 EP - 44 JF - Brain research JO - Brain Res VL - 1046 IS - 1-2 N2 - Our previous studies have indicated that the thalamic nucleus submedius (Sm) is involved in modulation of nociception as part of an ascending component of an endogenous analgesic system consisting of spinal cord-Sm-ventrolateral orbital cortex (VLO)-periaqueductal gray (PAG)-spinal cord loop. Microinjection of 5-hydroxytryptamine (5-HT) into Sm produces antinociception and this effect is blocked by 5-HT(2) receptor antagonist. The aim of the present study was to examine whether the 5-HT(1) and 5-HT(3) receptors were also involved in the Sm 5-HT-evoked antinociception. Nociception was assessed in lightly anesthetized rats with radiant-heat-evoked tail flick (TF). 5-HT(1A) and 5-HT(3) receptor antagonists were microinjected into the Sm alone or in combination with a microinjection of 5-HT into the same Sm site. 5-HT(1A) receptor antagonist p-MPPI (0.87 nmol) facilitated the TF reflex; a lower dose (0.43 nmol) of p-MPPI significantly attenuated the Sm 5-HT-evoked inhibition of TF reflex. Microinjection of the 5-HT(3) receptor antagonist LY-278,584 (12 nmol) had no effect either on the TF reflex or on the Sm 5-HT-evoked inhibition. These results suggest that 5-HT(1A) receptor but not 5-HT(3) receptor is involved in mediating the 5-HT-evoked antinociception. Possible mechanisms of Sm 5-HT-induced descending antinociception are discussed. SN - 0006-8993 UR - https://www.unboundmedicine.com/medline/citation/15869749/5_hydroxytryptamine_1A__5_HT1A__but_not_5_HT3_receptor_is_involved_in_mediating_the_nucleus_submedius_5_HT_evoked_antinociception_in_the_rat_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0006-8993(05)00450-6 DB - PRIME DP - Unbound Medicine ER -