L-histidine reduces inhibitory avoidance in Carassius auratus submitted to cerebellar ablation.
The effect of post-training treatment with L-histidine (LH) on the memory consolidation of inhibitory avoidance was investigated in Carassius auratus submitted to cerebellar ablation. The inhibitory avoidance procedure included 3 days: one habituation day, one training day (5 trials, T1-T5) and one test day. On the training day, each fish was placed individually in a white compartment separated from a black compartment by a sliding door. When the fish crossed into the black compartment, a weight was dropped in front of it (aversive stimulus) and the time to cross was recorded. Saline or LH (100 mg/kg) was injected intraperitoneally 10 min after the trials. Data were log10 transformed and analyzed by ANOVA and the Student-Newman-Keuls test (P < 0.05). In T5, all groups [ablation/LH (N = 15; 189.60 +/- 32.52), ablation/saline (N = 14; 204.29 +/- 28.95), sham/LH (N = 14; 232.36 +/- 28.15), and sham/saline (N = 15; 249.07 +/- 25.82)] had similar latencies that were significantly higher than T1 latencies [ablation/LH (89.33 +/- 20.41), ablation/saline (97.00 +/- 25.16), sham/LH (73.86 +/- 18.42), and sham/saline (56.71 +/- 17.59)], suggesting acquisition of inhibitory avoidance. For the test, there was a significant reduction in latencies of ablation/LH (61.53 +/- 17.70) and sham/saline (52.79 +/- 25.37) groups compared to the ablation/saline (213.64 +/- 29.57) and sham/LH (199.43 +/- 24.48) groups, showing that cerebellum ablation facilitated retention of inhibitory avoidance and LH reversed the effect of ablation. The results support other evidence that LH impairs memory consolidation and/or reduces the interpretation of aversion value.
Garção
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DC
Laboratório de Neurociências, Universidade Federal de São Carlos, Rodovia Washington Luiz, São Carlos, SP, Brazil.
Mattioli
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R
D055011:Ablation Techniques; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D002531:Cerebellum / Q000601:surgery*; D006054:Goldfish / Q000502:physiology* / Q000601:surgery; D006639:Histidine / Q000494:pharmacology*; D011930:Reaction Time
D006639:Histidine