Morphology and neurochemistry of the pelvic, and paracervical ganglia.

Autonomic ganglia are relays in the distribution of nerve fibres in the peripheral nervous system. In the pelvis there are local ganglion formations in the pathway of nerve fibres to and from pelvic viscera and vasculature: in rodents these are the male anterior major pelvic ganglion and the female paracervical ganglion (Frankenhäuser's ganglion). They are unusual in that they contain both sympathetic and parasympathetic ganglion cells. Homologous formations occur in humans. Since the best studied examples of these ganglionic formations are rodent ganglia the latter are reviewed in terms of their gross anatomy, cell morphology and immunohistochemistry. The synaptology, and neurotransmitter and neuropeptide contents of the neuronal perikarya and nerve terminals, of the ganglia are discussed in relation to the concepts of coexistence and chemical coding in autonomic ganglia in general. The neuropeptide content of the nerve fibres projecting to their visceral targets is described and discussed in functional terms. Conclusions are drawn with respect to the contributions made by study of these ganglia to further understanding of the organisation of the autonomic nervous system in general. The possible link between the autonomic nervous system and the endocrine system is discussed with respect to control of pelvic visceral activities.