title: Comparison of the Distributions of Neuropeptide Y-, Tyrosine Hydroxylase-, and Tryptophan Hydroxylase-Expressing Neurons in the Hypothalamic Arcuate Nucleus.
abstract: Several levels of interactions between serotonin and neuropeptide Y (NPY) have been proposed in the hypothalamic control of food intake. This study aimed at elucidating the anatomical relationship between the NPY-expressing neurons and the newly characterized neuronal population of tryptophan hydroxylase (TpH)-expressing (serotonin synthesizing enzyme) neurons in the hypothalamic arcuate nucleus. In addition, their distribution was compared to that of tyrosine hydroxylase (TH), the dopamine synthesizing enzyme. No co-localization of NPY and TpH, or NPY and TH was found in the arcuate nucleus either in intact or in colchicine-treated animals. These results suggest that there is likely no functional co-transmission between these transmitter systems in an intact arcuate nucleus.
authors.affiliation: a Department of Anatomy , Institute of Biomedicine, University of Helsinki , Finland ; Unit of Child Neurology , Hospital for Children and Adolescents, University Hospital of Helsinki , Finland.
authors.forename: S
authors.initials: S
authors.lastname: Vanhatalo
keywords: Arcuate nucleus; Hypothalamus; Neuropeptide Y; Serotonin; Tryptophan hydroxylase; Tyrosine hydroxylase