Role of Wnt/β-catenin signaling pathway in the expression of cocaine induced sensitization.

JORGELINA BATUECAS; SANTIAGO CUESTA; MARÍA J. SEVERIN; ROSSO SB; ALEJANDRA M. PACCHIONI

Huerta Grande

Congreso; XXVIII Congreso anual de la Sociedad Argentina de Investigaciones en Neurociencia & Reunión satélite/neurobiologia del comportamiento ?Neuroetologia y Neurobiologia de la Memoria en el Cono Sur.; 2013

SAN

The Wnt/b-catenin signaling pathway is activated by the interaction between the Wnt factors and their receptor Frizzled. While Wnt signaling pathway is essential for mammalian brain development, little is known regarding its role in adulthood. Recently we found that b-catenin levels are increased in the Nucleus Accumbens (NAcc) after cocaine induced sensitization. Our main goal was to investigate the relevance Wnt/b-catenin pathway in the expression of cocaine induced sensitization. In order to do that, adult male Wistar rats received daily injections of cocaine or saline for a week and then a challenge three weeks later. Locomotor activity was recorded on Day 1, 7 and 28. As it was expected, only rats chronically treated with cocaine showed a significant increase in locomotor activity on Day 28 compared to Day 1. Rats were sacrificed 24 hs after cocaine challenge on Day 28, and brains areas were dissected to study b-catenin expression levels. Our data showed that NAcc b-catenin is increased only after a cocaine injection while no changes were found after saline injection on Day 28. Furthermore, the increase in b-catenin only happened in sensitized animals while no changes were found in non-sensitized rats. In summary, our data showed that the increase in b-catenin in NAcc is induced by cocaine only when animals expressed locomotor sensitization, suggesting an important role of b-catenin in the expression of cocaine induced sensitization.