Sauroxine inhibits the hippocampal LTP

VALLEJO MG; ORTEGA, MG; CABRERA, JL.; ALMIRÓN, R; RAMÍREZ O; AGNESE AM

Córdoba, Arg

Otro; • XXXVIII Reunión anual de la Sociedad Argentina de Farmacología Experimental,; 2006

Sauroxine inhibits the hippocampal LTP

   The alkaloid extract (AE) of Huperzia saururus is constituted by a mixture of alkaloids, three of which occur as a majority: sauroine, sauroxine and 6-OH-lycopodine. In previous investigations we demonstrated that AE shows a facilitating effect on the LTP generation, as well as it was proved for sauroine, so this alkaloids it is one of the responsible for the AE activity. On the contrary, we reported that sauroxine inhibits  the LTP phenomena at a concentration of 1 µg/mL. Literature references  indicate that there are compounds that inhibit the LTP generation at certain concentrations whereas at  lesser ones they produce facilitation. 

   In view of these antecedents we evaluate sauroxine at a lesser concentration (0,5 µg/mL). Results showed that at this dose the alkaloid is still inhibiting the LTP. Controls showed an average  threshold of 75±11.0 Hz, whereas when it was perfused with sauroxine not LTP generation was achieved, even stimulating until 200 Hz.

   Further experiments at other doses will be assayed in order to determine whether sauroxine has a dual effect or definitely produce  an inhibition on the LTP generation.