Industrial exposure to cobalt causing optic atrophy and nerve deafness: a case report.

Letters to the Editor nicotinic receptors ' were substantially reduced in both AD and PD.There were no changes of the equilibrium dissociation constants (KD).The exact cellular location of nicotinic cholinergic receptors in the cerebral cortex is not known.The parallel changes in these receptors and CAT activity in AD and PD suggest that they are located pre-synaptically on degenerating cholinergic axons.This view is consistent with the finding that nicotine stimulates the release of acetylcholine from cholinergic terminals in the cortex.5The present results point to the potential for stimulation of the remaining nicotinic receptors as a treatment of the cholinergic deficit in AD and PD and provide a rationale for a therapeutic trial of selective nicotinic agonists.