Increased 5-HT3-mediated signalling in pelvic afferent neurons from mice deficient in P2X2 and/or P2X3 receptor subunits

• DOI: 10.1007/s11302-006-9017-z
• Publication Date: 2006-07-05T20:28:36Z
• Authors: Bei Ma; Gregory Wynn; Philip M. Dunn; Geoffrey Burnstock
• Keywords: Dorsal root ganglion

Extracellular ATP and 5-hydroxytryptamine (5-HT) are both involved in visceral sensory pathways by interacting with P2X 5-HT(3) receptors, respectively. We have investigated the changes 5-HT(3)-mediated signalling pelvic afferent neurons mice deficient P2X(2) and/or P2X(3) subunits whole-cell recording of L(6)-S(2) dorsal root ganglion (DRG) multi-unit afferents colorectum. In wildtype DRG neurons, evoked transient, sustained or mixed (biphasic) inward currents. Transient currents were absent (-/-) whereas neurons. Neither transient nor observed following application alpha,beta-methylene (alpha,beta-meATP) P2X(2)/P2X(3) (Dbl-/-) 5-HT was found to induce a fast current 63% from mice, which blocked tropisetron, receptor antagonist. The percentage responding significantly increased (2) (-/-), amplitude response mice. colorectal distension attenuated but serosal enhanced. Furthermore, tropisetron resulted greater reduction responses preparations. These data suggest that receptors containing mediate purinergic activation is up-regulated lacking genes. This effect more pronounced when absent.