Intermediate-term memory (ITM) is a stage ofmemory distinct fromsensory memory,working memory/short-term memory, andlong-term memory.[1][2][3] While sensory memory persists for several milliseconds, working memory persists for up to thirty seconds, and long-term memory persists from thirty minutes to the end of an individual's life, intermediate-term memory persists for about two to three hours.[4] This overlap in the durations of these memory processes indicates that they occur simultaneously, rather than sequentially. Indeed, intermediate-term facilitation can be produced in the absence of long-term facilitation.[5] However, the boundaries between these forms of memory are not clear-cut, and they can vary depending on the task.[6] Intermediate-term memory is thought to be supported by theparahippocampal cortex.[7]
In 1993, Rosenzweig and colleagues demonstrated that, in chicksconditioned with an aversive stimulus, percent avoidance of the stimulus (and, by implication, memory of the aversive nature of the stimulus) reachedrelative minima at one minute, fifteen minutes, and sixty minutes.[8] These dips were theorized to correspond to the time points in which the chicks switched from working memory to intermediate-term memory, from intermediate-term memory to the early phase of long-term memory, and from the early phase of long-term memory to the late phase of long-term memory, respectively—thus demonstrating the presence of a form of memory that exists between working memory and long-term memory, which they referred to as "intermediate-term memory".
Though the idea of intermediate-term memory has existed since the 1990s, Suttonet al. introduced a novel theory for the neural correlates underlying intermediate-term memory inAplysia in 2001, where they described it as the primary behavioral manifestation of intermediate-termfacilitation.[9]
Because intermediate-term memory does not involve transcription, it likely involves the translation of mRNA transcripts already present in neurons.[4][12][13][14][15][16][17][18][19][20][21][22]
While ITM requires only changes in translation, induction of long-term memory requires changes in transcription as well.[23] The change from short-term memory to long-term memory is thought to dependent onCREB, which regulates transcription, but because ITM does not involve a change in transcription, it is thought to be independent of CREB activity.[4] According to the definition of ITM proposed by Suttonet al. in 2001, it disappears completely before long-term memory is induced.[9]
^Grimes MT, Smith M, Li X, Darby-King A, Harley CW, McLean JH (March 2011). "Mammalian intermediate-term memory: new findings in neonate rat".Neurobiology of Learning and Memory.95 (3):385–91.doi:10.1016/j.nlm.2011.01.012.PMID21296674.S2CID29925493.
^Eichenbaum H, Otto T, Cohen NJ (2010). "Two functional components of the hippocampal memory system".Behavioral and Brain Sciences.17 (3):449–472.doi:10.1017/S0140525X00035391.S2CID144756396.
^Rosenzweig MR, Bennett EL, Colombo PJ, Lee DW, Serrano PA (November 1993). "Short-term, intermediate-term, and long-term memories".Behavioural Brain Research.57 (2):193–8.doi:10.1016/0166-4328(93)90135-D.PMID8117424.S2CID4016577.
^Parvez K, Moisseev V, Lukowiak K (July 2006). "A context-specific single contingent-reinforcing stimulus boosts intermediate-term memory into long-term memory".The European Journal of Neuroscience.24 (2):606–16.doi:10.1111/j.1460-9568.2006.04952.x.PMID16903862.S2CID21113626.
^Braun MH, Lukowiak K (September 2011). "Intermediate and long-term memory are different at the neuronal level in Lymnaea stagnalis (L.)".Neurobiology of Learning and Memory.96 (2):403–16.doi:10.1016/j.nlm.2011.06.016.PMID21757019.S2CID20487786.
