Prolactin Effects on Nigrostriatal and Mesolimbic Dopaminergic Neurons: In Vivo and In Vitro Studies

149 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987.In the present research, using both in vivo push-pull perfusion and in vitro superfusion techniques coupled to HPLC assay, the effect of prolactin on nigrostriatal and mesolimbic dopaminergic neuronal activity and its possible regulatory mechanism were examined.The current work led to the following conclusions: (1) The spontaneous afternoon-evening increase in in vivo 3,4-dihydroxyphenylacetic acid (DOPAC) output from the terminals but not from the somatodendrites of the mesostriatal dopaminergic system suggest a changes in presynaptic control. (2) Native prolactin can activate the release of dopamine (DA) from mesostriatal nerve terminals, but not from the cell bodies, as estimated by an increase in in vivo DOPAC output from the caudate nucleus and nucleus accumbens and an increase in in vitro DA release from both dorsal and ventral striatum. (3) Prolactin elicits specific behaviors such as yawning, stretching, and extensive grooming when push-pull cannula perfused a defined area within the caudate nucleus. Interesting, no such behaviors were induced when prolactin was infused into the nucleus accumbens. (4) Short-term prolactin does not enhance the in vivo tyrosine hydroxylase activity of mesostriatal nerve terminals. However, prolactin significantly activated tyrosine hydroxylase activity in the tuberoinfundibular DA neurons of the mediobasal hypothalamus. These data strongly argue in favor of current thinking considering that the corpus striatum as an important target-site for prolactin action in the central nerve system.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD