Expression of Peptides Derived from the Melanin-Concentrating Hormone Precursor in Serum-Free Culture of Rat Fetal Hypothalamic Neurons: Role of Attachment Factors

Abstract

A serum-free medium culture was developed in order to study the secretory behavior of neurons producing the melanin-concentrating hormone (MCH) precursor. The present results show that our culture conditions (supplemented RPMI 1640, poly-D-lysine substrate) are efficient in promoting attachment and growth of MCH neurons dissociated from rat fetal hypothalamus. These neurons acquire a differentiation stage in which neuropeptides of interest to us are expressed in a pattern similar to that observed on tissue sections: (1) coexpression of salmon MCH, growth-hormone-releasing factor (GRF37), α-melanocyte-stimulating hormone and acetylcholinesterase immunoreactivities, and (2) different intracellular distribution of salmon MCH and 1–37 sequence of GRF37 staining. Neurite growth was rapid and interneuronal connections were observed early. These observations suggest that our model of defined medium culture is suitable for functional investigations on MCH neurons.