Quinacrine-binding nerves: presence in the mouse ano-coccygeus muscle, disappearance after muscle transsection.

The anococcygeus muscle exhibits non-cholinergic, non-adrenergic, inhibitory neurotransmission. In the present paper we describe the presence of quinacrine-binding beaded nerve fibres in the mouse anococcygeus muscle. A large number of fibres were running parallel to the smooth muscle bundles. A second distribution of fibres formed an irregular plexus. No quinacrine-binding nerve cell bodies were found within the muscle. When the anococcygeus muscle was cut close to its insertion in the rectum, the proximal part lost most of its quinacrine-binding nerves 2-7 days after transsection. The results demonstrate a correlation between presumed non-cholinergic non-adrenergic neurotransmission and quinacrine-binding nervous elements.