Increased 5-HT(3)-mediated signalling in pelvic afferent neurons from mice deficient in P2X(2) and/or P2X (3) receptor subunits.

Abstract

Extracellular ATP and 5-hydroxytryptamine (5-HT) are both involved in visceral sensory pathways by interacting with P2X and 5-HT(3) receptors, respectively. We have investigated the changes in P2X and 5-HT(3)-mediated signalling in pelvic afferent neurons in mice deficient in P2X(2) and/or P2X(3) subunits by whole-cell recording of L(6)-S(2) dorsal root ganglion (DRG) neurons and by multi-unit recording of pelvic afferents of the colorectum. In wildtype DRG neurons, ATP evoked transient, sustained or mixed (biphasic) inward currents. Transient currents were absent in P2X(3) (-/-) neurons, whereas sustained currents were absent in P2X(2) (-/-) DRG neurons. Neither transient nor sustained curr..