Perinatal development of adrenergic, cholinergic and non-adrenergic, non-cholinergic nerves and sif cells in the rabbit urinary bladder.

The development of adrenergic (indicated by catecholamine fluorescence), acetylcholine-sterase-positive (possibly cholinergic), non-adrenergic, non-cholinergic (indicated by quinacrine fluorescence) nerves and small intensely fluorescent (SIF) cells in the rabbit urinary bladder was examined in foetal (from 23 days of gestation), newborn and adult animals. Acetylcholinesterase-positive nerve fibres and ganglion cells and quinacrine-positive ganglion cells were both present on day 23 of gestation, while quinacrine-positive varicose nerve fibres were first seen on day 24. At foetal age 26 days, 25-38 ganglia containing quinacrine-positive cells were seen in whole-mount preparations of detrusor muscle of the bladder. Each ganglion contained 30-40 quinacrine-positive cells (diameter 20-40 μm). In contrast, only 5-12 ganglia contained acetylcholinesterase-positive nerve cell bodies at the same foetal age with only 3-20 cells in each ganglion; these figures remained at about the same level from foetal age 23 days to maturity. No catecholamine-containing nerve cell bodies were seen at any foetal age or in the adult. Adrenergic nerve fibres were not detected until day 28 of gestation, although small intensely fluorescent cells were first observed on day 26 of gestation. In the adult bladder there was a reduction of approximately 25-35% in the number of quinacrine-positive nerve cell bodies within the ganglia when compared with the ganglia in 1-day-old bladders and an increase in nerve fibre density of about 50% when compared with bladders of earlier ages. A reduction of approximately 90% in small intensely fluorescent cells and a 2-fold increase of adrenergic nerves was also characteristic of the adult bladder, although no changes were observed in the density of the acetylcholinesterase-positive cell bodies and nerve fibres. It is concluded that catecholamine-containing, acetylcholinesterase-positive and non-adrenergic, non-cholinergic nerves follow very different developmental patterns in the bladder.