Neonatal X radiation: hippocampal morphology and anxiety state

CACERES L.G.; CID M.P., ; SARRACENO G.E.; ROMERO J.I.; URAN S.L., ; CAPAN F; SALVATIERRA N.A.; GUELMAN L.R.

Congreso; IIIRCN, Third joint meeting of the argentine society for neurosciences (SAN) and the argentine workshop in neurosciences (TAN).; 2011

"Neonatal X radiation: hippocampal morphology and anxiety state" Lucila Guadalupe Caceres1, Mariana Paula Cid2, Gustavo Ezequiel Saraceno3, Juan Ignacio Romero3, Soledad Lucía Uran1, Francisco Capani3, Nancy Alicia Salvatierra2, Laura Ruth Guelman1 11er Cátedra de Farmacología, Facultad de Medicina (UBA)-CEFYBO (CONICET), 2Cátedra de Química Orgánica Biológica, Facultad de Ciencias Exactas Físicas y Naturales. UNC. Córdoba, Argentina, 3Laboratorio de plasticidad y citoarquitectura neuronal. ININCA-CONICET. Buenos Aires, Argentina.lugcaceres@gmail.com   Ionizing radiation (Rx) is a physical agent broadly used in therapeutic medicine, being the developing Central Nervous System particularly vulnerable. Since a decrease in anxiety levels has been observed in neonatally irradiated rats, which could underlie several memory changes, and considering an implication of GABA in both mechanisms, the aim of the present work was to address the involvement of the GABAergic system in these Rx-induced alterations. Moreover, since a relationship between dendritic spines, GABAergic neurotransmission and memory processes have been postulated, the density of dendritic spines in the hippocampus (Hip) was also assessed. Male Wistar rats were irradiated with 5 Gy of X rays in their cephalic ends between 24 and 48 hours after birth. GABAA receptor binding assay and morphological assessment of mushroom dendritic spines were performed in Hip of 30-days-old rats. Results show that the decrease in anxiety levels observed in irradiated rats is correlated with an increase of GABAA receptor density observed in synaptosomes from Hip of irradiated rats. Moreover, the increase in the number of mushroom dendritic spines Faloidine (+) in CA1 region of the Hip of irradiated group could explain, at least in part, the increase of GABAA receptor density.