Circuit compensation is often observed in patients with acute ischemic stroke, suggesting the importance of the interaction between brain regions. Also, contextual fear memory is an association between multisensory contexts and fearful stimuli, for which the interaction between the hippocampus and the amygdala is believed to be critical. To understand how focal ischemia in one region could influence the other region, we used a modified photo-thrombosis to induce focal ischemia in the hippocampus or the amygdala or both in freely-moving rats. We found that the learning curve and short-term memory (STM) were not affected in the rats although focal ischemia was induced 5 h before learning in either the hippocampus or the amygdala; these were impaired by the induction of ischemia in both the regions. Furthermore, the learning curve and STM were impaired when ischemia was induced 24 h before learning in either the hippocampus or the amygdala when the synaptic transmission was altered in one region because of ischemia in the other region. These results suggest that the circuit compensation between the hippocampus and the amygdala is critical for fear memory acquisition.
Bibliographical noteFunding Information:
This work was supported by Natural Science Foundation of China Grants 31100775 and 31371141 (to Q.-X.Z.), U15022058 (to L.X.), 31860272 (to P.G.), and 31861143037 (to L.X. and G.R.-L.); the Strategic Priority Research Program of the Chinese Academy of Sciences Grant XDB32020000 (to L.X.); the Department of Science and Technology Program of Yunnan Province Grant 2016HA002 (to L.X.); the External Cooperation Program BIC of the Chinese Academy of Sciences Grant GJHZ1549 (to G.R.-L.); and the Youth Innovation Promotion Association of the Chinese Academy of Sciences Grant 2013250 (to Q.-X.Z.).
© 2021 Yu et al.
- Fear memory
ASJC Scopus subject areas
- Neuroscience (all)