Age-associated changes in distribution of the P2X2 receptor in the major pelvic ganglion of the male rat.

Neurogenic mechanisms in bladder and bowel ageing

“…The cause of these degenerative changes with age is yet to be fully determined but impaired calcium regulation and signalling may play a role since the calcium binding protein Calbindin-D28K has been shown to significantly decrease with ageing in sympathetic MPG cells of rats (Corns et al 2000 ). In the few other studies of aged MPG a decrease in the expression of brain nitric oxide synthase in the ganglion, no significant changes in purinergic P2X2 receptor expression and increased deposition of connective tissue have been reported (Warburton and Santer 1997 , Salama et al 2002 ; Dowling et al 2006 ). Putting the current evidence together, the key observation, particularly from Santer’s work, is that there is a clear and selective attrition of sympathetic cells within the MPG whilst parasympathetic cells appear to remain largely unaffected by ageing in these studies (Santer et al 2002 ).…”

“…In small rodents such as rats and mice the majority of the postganglionic neurons that supply the pelvic viscera are located in the major pelvic ganglion (MPG), which is equivalent to the more diffuse plexus of postganglionic cells supplying the pelvic organs of larger mammals (Santer et al 2002 ). Furthermore the MPG in these animals contains groups of both parasympathetic and sympathetic postganglionic neurons making it a useful model to compare age-related changes in the efferent outflows to the pelvic viscera (Warburton and Santer 1993 , 1994 ; Santer et al 2002 ; Dowling et al 2006 ). The parasympathetic fibres that regulate bladder function release acetylcholine and stimulate muscle contraction, whereas the sympathetic fibres stimulate relaxation by noradrenergic signalling.…”