Mello e Souza T, Rohden A, Meinhardt M, Gonçalves CA, Quillfeldt JA. S100B infusion into the rat hippocampus facilitates memory for the inhibitory avoidance task but not for the open-field habituation.
Physiol Behav 2000;
71:29-33. [PMID:
11134682 DOI:
10.1016/s0031-9384(00)00299-7]
[Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Adult male Wistar rats were bilaterally implanted with indwelling cannulae in the hippocampus. Forty-eight hours after surgery, animals were habituated to an open-field box during 2 min, being tested 24 h later; next they were trained in a step-down inhibitory avoidance task (3.0 s, 0.4 mA foot-shock), being tested again 24 h later. Immediately after the training session of each task, animals received a 0.5-microl infusion of calcium-phosphate-buffered saline (PBS) and S100B (20, 200, 2000, or 20,000 nM). In the inhibitory avoidance task, animals infused with the two highest concentrations of S100B, 2 and 20 microM, obtained higher scores of retention relative to controls in the test session (p<0.05), and a trend toward an increase was observed in animals infused with 200 nM (p<0. 10). In both sessions of the habituation task, groups were not different regarding crossings, rearings, and time for leaving the first square (p>0.10). These results indicate that, in rats, post-training increased hippocampal levels of S100B right after training facilitate, in a dose-dependent way, long-term memory for an inhibitory avoidance task, but not for an open-field habituation.
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