Effect of dopamine antagonism on carotid chemoreceptor interspike intervals.

As a means of examining the role of dopamine in chemotransduction, we examined the spike interval pattern from single carotid body chemoreceptors before and following dopamine antagonism. Before dopamine antagonism, chemoreceptor joint interval variability was less than the variability of the same spike interval series placed in shuffled order. This lower variability was abolished by dopamine antagonism with haloperidol. These data suggest that dopamine release reduces chemoreceptor interspike variability in vivo and that endogenous, local dopamine release is related to the activity level of a single chemoreceptor afferent.