DISTRIBUTION OF NEURONS EXPRESSING 5-HT_(1A,2A/) RECEPTOR mRNAs IN THE RAT SPINAL CORD AND DORSAL ROOT GANGLION / 解剖学报

ABSTRACT

Objective\ To observe the expression of 5\|HT 1A and 5\|HT 2A receptor mRNAs in the rat spinal cord and dorsal root ganglion(DRG). Methods\ In situ hybridization histochemical technique. Results\ (1)5\|HT\-\{1A\} receptor mRNA positive neurons were found in all laminae of the gray matter,mainly in the superficial laminae(laminae Ⅰ and Ⅱ),laminae Ⅲ and Ⅳ of the dorsal horn.Scattered positive neurons were also observed in laminae Ⅴ\|Ⅶ and Ⅹ.Very few positive signals were found in the ventral horn(lamnina Ⅸ);(2)5\|HT\-\{2A\} receptor mRNA positive neurons were mainly found in the superficial laminae and ventral horn,while sparsely distributed positive neurons were also located in other laminae.Within the DRG(1)About 10^4% of the total DRG cells were labeled with 5\|HT 1A receptor mRNA.The positive signals were mainly confined to a subpopulation of small\| and medium\|sized cells;(2)About 17^4% of the total DRG cells were labeled with 5\|HT 2A receptor mRNA,most of them were also small\| and medium\|sized cells. Conclusions\ 5\|HT 1A and 5\|HT 2A receptor mRNAs positive neurons distributed heterogeneously in the rat spinal cord and DRG, they may play important roles for 5\|HT in the analgesic effects at the spinal level and nociception in the periphery.\;