Postnatal Development of the Pars Nervosa of the Pituitary Gland of Male Albino Rat: Histological and Immuno-Histochemical Study

Introduction: Communication between neurons and glial cells can affect neuronal excitability and synaptic transmission. At different ages, the activation of the neuroglial cells and the changes of their function can reflect the regulative ability of the nervous system. Aim of the Work: This wok aimed to study the postnatal changes of the pituicytes, the resident astroglia of the pars nervosa. Materials and Methods: Thirty male albino rats were divided into 3 groups, 10 animals each, group I (neonatal), group II (adult) and group III (senile). The animals were dissected and the pituitary glands were processed for histological, histochemical and immune-histochemical studies. Results: Hematoxyline and Eosin stained sections revealed an apparent increase in number of pituicytes in group III compared with other groups. Moreover, there was an increase in the extracellular spaces around nerve terminals and blood capillaries. The pituicytes of groups II and III showed vacuolated cytoplasm. In senile rats, there was an accumulation of PAS +ve neuro-secretory granules in the axon terminals. GFAP immuno-stain revealed an apparent decrease in pituicytes with GFAP +ve reaction in senile group compared with other groups.. Conclusion: The number of pituicytes increased with age accompanied by decrease in their GFAP reactivity with increased PAS +ve granules in axon terminals.