| We hypothesized that multiple drug state training would abolish state-dependent retrieval (SDR) deficits. In Experiment 1, rats received one-way avoidance (AVDNC) training either in a pentobarbital-(Pent) drugged (D) state or in an atropine-(Atrp) D state followed by training in a Pent-D state; both groups were then tested non-drugged (ND) in the same apparatus/room and later also in a different physical context. Atrp-trained rats performed worse than Pent-trained rats. Changing drug conditions from Atrp to Pent or from Pent to ND produced SDR deficits; however, there was a larger Pent-ND deficit in rats initially trained with Atrp. Neither group showed a deficit when tested ND in a different physical context.; In Experiment 2, we attempted to determine if ND retrieval of a D-stored memory in one task (water T-maze) would reduce SDR deficits in a second, independent task (AVDNC). In the T-maze, rats which received Atrp or Pent performed worse on the training day than ND-trained rats. On the Test Day, only Atrp injected rats were impaired. There was no SDR deficit on the water T-maze. All rats then received AVDNC training D with Pent, followed by ND training, followed by Atrp-D training. There was a SDR deficit for the Pent-ND shift and then again for the ND-Atrp shift. On the second and third days of ND training, those rats which had previous experience with Pent in the water T-maze performed more poorly than the other groups. This is likely due to interference by information acquired in same D state. Retrieval was markedly impaired during all three days of Atrp training.; Rats with previous experience in D-ND retrieval or with training in multiple drugs failed to show an attenuated SDR deficit. Thus, there appears to be no benefit of multiple-D state encoding relative to single-state encoding. |
