Parvalbumin Immunoreactivity Changes during the Maturation of the Thalamic Reticular Nucleus of the Rat

The thalamic reticular nucleus is a thin layer of GABAergic cells located between the external medullary lamina and the internal capsule surrounding the rostolateral surface of the thalamus. It has functionally distinct afferent and efferent connections with thalamic nuclei, the neocortex, the basal forebrain and the brainstem. Parvalbumin is a calcium-binding protein, which is regarded to be a marker for GABAergic neurons. The thalamic reticular neurons are GABAergic, and parvalbumin is always colocalized with GABA in these cells. We have demonstrated the parvalbumin immunoreactivity in the thalamic reticular nucleus at different stages of postnatal development of rats, as well at 1-year-old rats. It was established that the maturation of immunoposive patterns varies in different parts of the nucleus. The intensity of immunostaining decreases with age.