TY - JOUR
T1 - Novelty exposure overcomes foot shock-induced spatial-memory impairment by processes of synaptic-tagging in rats
AU - Almaguer-Melian, William
AU - Bergado-Rosado, Jorge
AU - Pavón-Fuentes, Nancy
AU - Alberti-Amador, Esteban
AU - Mercerón-Martínez, Daymara
AU - Frey, Julietta U.
PY - 2012/1/17
Y1 - 2012/1/17
N2 - Novelty processing can transform short-term into long-termmemory. We propose that this memory-reinforcing effect of novelty could be explained by mechanisms outlined in the "synaptic tagging hypothesis."Initial short-term memory is sustained by a transient plasticity change at activated synapses and sets synaptic tags. These tags are later able to capture and process the plasticity-related proteins (PRPs), which are required to transform a short-term synaptic change into a long-termone. Novelty is involved in inducing the synthesis of PRPs [Moncada D, et al. (2011) Proc Natl Acad Sci USA 108:12937-12936], which are then captured by the tagged synapses, consolidatingmemory. In contrast to novelty, stress can impair learning, memory, and synaptic plasticity. Here, we address questions as towhether novelty-induced PRPs are able to prevent the loss ofmemory caused by stress and if the latter would not interact with the tag-setting process. We usedwater-maze (WM) training as a spatial learning paradigmto test our hypothesis. Stress was induced by a strong foot shock (FS; 5 x 1 mA, 2 s) applied 5 min after WM training. Our data show that FS reduced long-term but not short-term memory in the WM paradigm. This negative effect onmemory consolidationwas time- and training-dependent. Interestingly, novelty exposure prevented the stress-induced memory loss of the spatial task and increased BDNF and Arc expression. This rescuing effectwas blocked by anisomycin, suggesting that WM-tagged synapses were not reset by FS and were thus able to capture the novelty-induced PRPs, re-establishing FS-impaired long-term memory.
AB - Novelty processing can transform short-term into long-termmemory. We propose that this memory-reinforcing effect of novelty could be explained by mechanisms outlined in the "synaptic tagging hypothesis."Initial short-term memory is sustained by a transient plasticity change at activated synapses and sets synaptic tags. These tags are later able to capture and process the plasticity-related proteins (PRPs), which are required to transform a short-term synaptic change into a long-termone. Novelty is involved in inducing the synthesis of PRPs [Moncada D, et al. (2011) Proc Natl Acad Sci USA 108:12937-12936], which are then captured by the tagged synapses, consolidatingmemory. In contrast to novelty, stress can impair learning, memory, and synaptic plasticity. Here, we address questions as towhether novelty-induced PRPs are able to prevent the loss ofmemory caused by stress and if the latter would not interact with the tag-setting process. We usedwater-maze (WM) training as a spatial learning paradigmto test our hypothesis. Stress was induced by a strong foot shock (FS; 5 x 1 mA, 2 s) applied 5 min after WM training. Our data show that FS reduced long-term but not short-term memory in the WM paradigm. This negative effect onmemory consolidationwas time- and training-dependent. Interestingly, novelty exposure prevented the stress-induced memory loss of the spatial task and increased BDNF and Arc expression. This rescuing effectwas blocked by anisomycin, suggesting that WM-tagged synapses were not reset by FS and were thus able to capture the novelty-induced PRPs, re-establishing FS-impaired long-term memory.
KW - Memory reinforcement
KW - Memory rescue
KW - Novelty exploration
UR - http://www.scopus.com/inward/record.url?scp=84856407401&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84856407401&partnerID=8YFLogxK
U2 - 10.1073/pnas.1114198109
DO - 10.1073/pnas.1114198109
M3 - Article
C2 - 22215603
AN - SCOPUS:84856407401
SN - 0027-8424
VL - 109
SP - 953
EP - 958
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 3
ER -