| First Author | Cravens CJ | Year | 2006 |
| Journal | Eur J Neurosci | Volume | 24 |
| Issue | 6 | Pages | 1771-80 |
| PubMed ID | 17004940 | Mgi Jnum | J:112944 |
| Mgi Id | MGI:3664028 | Doi | 10.1111/j.1460-9568.2006.05044.x |
| Citation | Cravens CJ, et al. (2006) CA3 NMDA receptors are crucial for rapid and automatic representation of context memory. Eur J Neurosci 24(6):1771-80 |
| abstractText | It is argued that the hippocampus contributes to acquisition of context-specific memory although neural mechanisms have not been clarified. To evaluate the role of CA3 in context-specific memory, we developed one-trial context discrimination tasks to test acquisition and retrieval of contextual memory in CA3 pyramidal cell-restricted N-methyl-d-aspartate (NMDA) receptor knockout mice. Mutants were unable to discriminate conditioned and no-shock contexts 3 h after one-trial avoidance training. These phenotypes were not evident 24 h after one-trial training or 3 h after multi-trial training. Following one-trial contextual fear conditioning, mutants showed a selective deficit in context discrimination during a retention test 3 h after acquisition, although overall freezing levels were similar to those of the control mice. As in the avoidance task, this context discrimination impairment was not observed 24 h after initial conditioning. Interestingly, extending the post-shock period to 3 min during the one-trial fear conditioning task eliminated the discrimination deficit observed at the 3 h retention interval. These results suggest that: (i) impaired rapid context discrimination during the recall test is dependent on the duration of post-shock period during conditioning; (ii) CA3 NMDA receptors are critically involved in rapid and automatic formation of a unified context memory representation from the sensory information; (iii) CA3 NMDA receptors support contextual pattern separation; (iv) fear memory to foot-shock is acquired without CA3 NMDA receptors. It appears that rapid and automatic context memory representations from one-time experience are mediated, at least in part, by CA3 NMDA receptors. |
