Mz. Li et S. Masuko, Target specific organization and neuron types of the dog pelvic ganglia: Aretrograde-tracing and immunohistochemical study, ARCH HIST C, 64(3), 2001, pp. 267-280
The major pelvic ganglion in both the rat and guinea pig has been extensive
ly studied because of its anatomical simplicity. To clarify the target spec
ific neural pathway in the diffusely distributed pelvic ganglia of larger a
nimals, the pelvic plexus of the female dog was investigated by retrograde
tracing and immunohistochemistry. The whole mount staining of the pelvic pl
exus with acetylcholinesterase histochemistry revealed 70-100 ganglia of va
rying sizes. Neurons retrogradely labeled from the rectum were mainly found
in ganglia located in the dorso-caudal part of the plexus. The majority of
these were non-catecholaminergic, immunoreactive for either calbindin (Cal
b) or neuropeptide Y (NPY), and characteristically associated with baskets
of enkephalin (ENK)-immunoreactive varicose fibers. Neurons projecting to t
he utero-vaginal walls were distributed in ganglia located in the ventro-ca
udal part of the plexus. These mainly consisted of two major neuron groups:
catecholaminergic Calb-immunoreactive neurons, and non-catecholaminergic n
eurons containing nitric oxide synthase (NOS) and/or vasoactive intestinal
peptide (VIP), which were preferentially associated with a network of ENK-i
mmunoreactive varicose fibers. Neurons retrogradely labeled from the urinar
y bladder mainly occurred in ganglia located around the junction between th
e ureter and the bladder. These consisted of catecholaminergic Calb neurons
and noncatecholaminergic neurons containing Calb or NOS. Only a few ENK-im
munoreactive fibers were found within the clusters of catecholaminergic neu
rons. These results indicate that organ specific neurons are located in sep
arate ganglia and have both a distinctive composition of neuron types as we
ll as different innervation by preganglionic fibers.