Angiotensin II AT2 receptors localized at immunoreactive neurons in the inferior colliculus at developmental stages.

ARCE, MARÍA ELENA; SANCHEZ S,; FUENTES L.B.; CIUFFO, GM

Congreso; Reunion SOBLA 2013; 2013

Angiotensin II AT2 receptors localized at immunoreactive neurons in the inferior colliculus at developmental stages. Arce María E., Sánchez Susana I., Fuentes Lucia B., Ciuffo Gladys M. IMIBIO-SL CONICET- Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis. Argentina The classical effects of Angiotensin II (Ang II) are well-known but new evidences involve this peptide in development and organogenesis. It can also modulate neuronal activity in brain regions involved in cognition, motor control and sensory integration. Ang II recognizes two receptor subtypes, named as AT1 and AT2, based on pharmacological basis. The Inferior Colliculus (IC) is a critical midbrain station for the auditory processing, involved with motor activities related to audition. Previously, we studied Ang II receptor localization by binding autoradiography in midbrain and hindbrain of newborn rats at different stages (P0, P8 and P15). Specific binding at the IC increased with age, being maximal at P15 with prevalence of AT2 receptors, in agreement with higher AT2 receptor mRNA expression at this stage. The aim of this work was to study the localization of AT2 receptor in the IC in P15 animals by immunofluorescence assays and to identify cellular types. Immunofluorescence staining with anti AT2 receptor antibody and Anti β III ?Tubulin antibody (specific neuronal marker) recognize the same neurons, thus indicating the AT2 labeled cells are neurons. Immunoreactive neurons also exhibited selective Ang II AT2 binding by autoradiography. The pattern of Ang II AT2 receptor´s expression in the IC encompasses the pattern of the brainstem maturation and connection to the cerebral system. Since IC was involved in the the auditory processing and scape behavior, we can assume that AT2 receptors might play a potential role in organogenesis and the establishment of neuronal circuits.