Adrenergic drugs modify the level of noradrenaline in the insular cortex and alter extinction of conditioned taste aversion in rats.

摘要: We compared the effect of conditioned taste aversion in rats by measuring amount sucrose that they drunk after conditioning, which differed according to whether had freely (SD: self drinking) during conditioning session, or been forced drink it (IO: intra-oral administration through a chronically implanted cannula). The SD procedure delayed extinction aversion. Enhanced arousal, alertness, awareness attention condition may have strengthened memory taste. Brain noradrenergic networks are involved such processes. administered two drugs produce opposite effects on noradrenaline release brain, methoxy-idazoxan, RX821002 (1mg/kg, i.p.), and guanfacine (0.12mg/kg, i.p.). evaluated their (i) level gustatory cortex using microdialysis, (ii) glycaemia is an essential factor learning (iii) comparative versus IO protocol mentioned above. Injecting RX821001 increased up two-fold baseline. This lasted 1h. same dose did not elicit any alteration glycaemia. It enhanced group rats. 0.12mg/kg produced effect. decreased, but only down 20% decrease 2h. Guanfacine Extinction was marginally decreased These results fit with Aston-Jones' point view role coeruleo-cortical system be enhance event transient increase cortical noradrenaline.