PACAP Expression in Explant Cultured Mouse Major Pelvic Ganglia

Abstract

The major pelvic ganglia (MPG) contain both parasympathetic and sympathetic postganglionic neurons and provide much of the autonomic innervation to urogenital organs and components of the lower bowel. Whereas many parasympathetic neurons were found to express vasoactive intestinal polypeptide (VIP), no MPG neurons exhibited immunoreactivity for pituitary adenylate cyclase activating polypeptide (PACAP). However, in 3-day cultured MPGs, numerous PACAP-IR cells and nerve fibers were present and transcript levels for PACAP increase As the MPG contains both sympathetic and parasympathetic postganglionic neurons, d significantly. In 3-day cultured MPGs, PACAP immunoreactivity was seen in cells that were also immunoreactive for VIP or neuronal nitric oxide synthase (nNOS), but not tyrosine hydroxylase (TH), indicating that PACAP expression occurred preferentially in MPG parasympathetic postganglionic neurons. Transcript levels for the VPAC2, but not VPAC1 or PAC1 receptor, also increased significantly following 3 days in culture. Transcript levels of activating transcription factor 3 (ATF-3), a marker of cellular injury, were increased 64-fold in 3-day explants and ATF-3-IR nuclei were evident in both TH-IR and nNOS-IR neurons as well as in non-neuronal cells. In sum, these results demonstrate that although only the parasympathetic neurons in explant cultured MPGs increase expression of PACAP, both sympathetic and parasympathetic postganglionic neurons in the cultured MPG whole mount increase expression of ATF-3.

Decrease in neuronal nicotinic acetylcholine receptor subunit and PSD-93 transcript levels in the male mouse MPG after cavernous nerve injury or explant culture

“…As in previous studies (3,4), mice were euthanized by an overdose of isoflurane followed by thoracotomy.…”

“…Intact whole mount MPG preparations, which contained both neural and non-neural cells, were removed under sterile conditions after euthanasia as previously described (3,4). Whole mounts were maintained at 37°C in culture media consisting of DMEM-F-12 (1:1) containing 10% horse serum, gentamicin (10 g/ml), amphotericin B (3.75 g/ml), penicillin (100 U/ml), and streptomycin (100 g/ml, Sigma, St. Louis, MO).…”

“…The quantitative real-time PCR procedures followed those used in our previous studies (3,4). In brief, total RNA was extracted under RNAse-free conditions.…”

“…These observations are consistent with a separation of preganglionic terminals from penile projecting postganglionic neurons. However, these authors did not assess whether there was a change in AChR subunit expression.In previous studies, we (3,4) identified changes in the chemical phenotype of neurons within the male mouse MPG that change in response to axotomy. In mice, the MPG are readily accessible, and axons from a subset of MPG neurons project via the well-defined cavernous nerve to penile tissues (7).…”

“…In previous studies, we (3,4) identified changes in the chemical phenotype of neurons within the male mouse MPG that change in response to axotomy. In mice, the MPG are readily accessible, and axons from a subset of MPG neurons project via the well-defined cavernous nerve to penile tissues (7).…”