Abstract

The effects on cerebrospinal fluid (CSF) production of specific agonists and antagonists for the autonomic nervous system were studied during ventriculocisternal perfusion in cats. Both carbachol and phenylephrine increased the rate of CSF formation 11 microliter/min from control rates of 17 and 11 microliter/min, resepctively; albuterol increased formation 6 microliter/min above the control 16 microliter/min. Atropine or phentolamine administered alone caused slight but significant decreases in CSF production; propranolol had no effect. All three antagonists reduced the changes in fluid formation elicited by their respective agonists. Atropine also blocked the action of phenylephrine. Hemicholinium-3, which reduced the synthesis of acetylcholine, sharply attenuated the increase caused by phenylephrine. These observations were taken to indicate that phenylephrine increased CSF production by stimulating a cholinergic pathway to the choroid plexus. Bilateral electrical stimulation of the cervical sympathetic trunks decreased CSF formation. Agents which increased CSF production caused no significant changes in cerebral or choroid plexus blood flow, possibly indicating that their effect is a direct action on the choroid plexus secretory mechanisms.