Comparative anatomy of α2 and β adrenoceptors in the adult and developing brain of the marine teleost the red porgy (Pagrus pagrus, Sparidae): [3H]clonidine and [3H]dihydroalprenolol quantitative autoradiography and receptor subtypes immunohistochemistry

摘要: The present study aimed to determine the anatomic distribution and developmental profile of alpha(2) beta adrenoceptors (AR) in marine teleost brain. Alpha 2 were studied at different stages by using [(3)H]clonidine [(3)H]dihydroalprenolol, respectively, means vitro quantitative autoradiography. Furthermore, immunohistochemical localization receptor subtypes was performed their cellular distribution. Saturation studies determined a high-affinity component [(3)H]dihydroalprenolol binding sites. High levels both receptors found preglomerular complex, ventral hypothalamus, lateral torus. Dorsal hypothalamus isthmus included high AR, whereas pretectum molecular proliferative zone cerebellum specifically characterized densities AR. From first year life, adult AR most medial telencephalic, hypothalamic, posterior tegmental areas. Decreases with age prominent pretectal, thalamic, brain regions. Immunohistochemical data well correlated autoradiography demonstrated presence alpha(2A), alpha(2C), beta(1), beta(2) subtype-like immunoreactivity. Both neuronal (perikaryal or dendritic) glial revealed. age-dependent alterations parallel plasticity mechanisms, such as cell proliferation periventricular thalamus, cerebellum. In addition, biochemical characteristics, pattern, specificity support similar noradrenergic transmission vertebrate evolution.