Effects of immunoneutralization of dynorphin1-17 and dynorphin1-8 on the activity of central dopaminergic neurons in the male rat.

Abstract

The effects of administration of antibodies against dynorphin1-17 (DYN1-17-AB) and dynorphin1-8 (DYN1-8-AB) were examined on the activity of dopaminergic (DA) neurons comprising the nigrostriatal, mesolimbic, tuberoinfundibular and periventricular-hypophysial systems in the male rat brain. DA neuronal activity was estimated by measuring the concentration of the dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) in brain (striatum, nucleus accumbens, median eminence) and pituitary regions (intermediate lobe) containing terminals of these neurons. The intracerebroventricular administration of either DYN1-17-AB or DYN1-8-AB produced a time-related increase in the activity of tuberoinfundibular and periventricular-hypophysial DA neurons, but failed to alter the activity of nigrostriatal or mesolimbic DA neurons. The ability of both DYN1-17-AB and DYN1-8-AB to enhance the activity of tuberoinfundibular and periventricular-hypophysial DA neurons was reversed by the kappa opioid agonist U-50,488. These results indicate that DYN1-17-AB and DYN1-8-AB, presumably by binding endogenous dynorphins, remove a tonic inhibitory action of these opioid peptides on tuberoinfundibular and periventricular-hypophysial DA neurons.

Cite this paper

@article{Manzanares1992EffectsOI, title={Effects of immunoneutralization of dynorphin1-17 and dynorphin1-8 on the activity of central dopaminergic neurons in the male rat.}, author={Jorge Manzanares and Erik J. Wagner and Keith J. Lookingland and Kenneth E. Moore}, journal={Brain research}, year={1992}, volume={587 2}, pages={301-5} }