Histochemical, ultrastructural, and functional evidence for a neurogenic control of CSF production from the choroid plexus.

Histochemical studies have shown that the rabbit choroid plexus receives a well-developed adrenergic and cholinergic nerve supply. The adrenergic innervation, which originates almost entirely from the superior cervical sympathetic ganglia, begins to develop around birth and is fully established 3 weeks later. Electron microscopy has shown that the nerve terminals innervate both the plexus arterioles and its secretory epithelium. The sympathetic fibers have been shown to influence the plexus epithelium, as reflected by their effect on its carbonic anhydrase activity. They appear to have an inhibitory effect on the bulk CSF production, as revealed by electrical nerve stimulation and denervation experiments. The control seems to be exerted primarily on the plexus epithelium, although some of the effect may also be associated with alterations in choroid plexus blood flow.