Intermediate-term memory (ITM) is a stage of memory distinct from sensory memory, working memory/short-term memory, and long-term memory. 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. 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. However, the boundaries between these forms of memory are not clear-cut, and they can vary depending on the task. Intermediate-term memory is thought to be supported by the parahippocampal cortex.
In 1993, Rosenzweig and colleagues demonstrated that, in rats conditioned with an aversive stimulus, percent avoidance of the stimulus (and, by implication, memory of the aversive nature of the stimulus) reached relative minima at one minute, fifteen minutes, and sixty minutes. These dips were theorized to correspond to the time points in which the rats 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, Sutton et al. introduced a novel theory for the neural correlates underlying intermediate-term memory in Aplysia in 2001, where they described it as the primary behavioral manifestation of intermediate-term facilitation.
In 2001, Sutton and colleagues proposed that intermediate-term memory possesses the following three characteristics:
- Its induction requires translation, but not transcription
- Its expression requires the persistent activation of protein kinase A and protein kinase C
- It declines completely before the onset of long-term memory
Comparison with short-term/working memory
Unlike short-term memory and working memory, intermediate-term memory requires changes in translation to occur in order to function.
Comparison with long-term memory
While ITM requires only changes in translation, induction of long-term memory requires changes in transcription as well. The change from short-term memory to long-term memory is thought to dependent on CREB, which regulates transcription, but because ITM does not involve a change in transcription, it is thought to be independent of CREB activity. According to the definition of ITM proposed by Sutton et al. in 2001, it disappears completely before long-term memory is induced.
- 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. PMID 21296674.
- Sutton MA, Carew TJ (August 2002). "Behavioral, cellular, and molecular analysis of memory in aplysia I: intermediate-term memory". Integrative and Comparative Biology. 42 (4): 725–35. doi:10.1093/icb/42.4.725. PMID 21708769.
- Lukowiak K, Adatia N, Krygier D, Syed N (2000). "Operant conditioning in Lymnaea: evidence for intermediate- and long-term memory". Learning & Memory. 7 (3): 140–50. doi:10.1101/lm.7.3.140. PMC 311329. PMID 10837503.
- Mauelshagen J, Sherff CM, Carew TJ (1998). "Differential induction of long-term synaptic facilitation by spaced and massed applications of serotonin at sensory neuron synapses of Aplysia californica". Learning & Memory. 5 (3): 246–56. doi:10.1101/lm.5.3.246 (inactive 2019-02-22). PMC 313806. PMID 10454368.
- Raymond P. Kesner and Joe L. Martinez, Jr. (eds) (2007). Neurobiology of Learning and Memory, 2nd edition. Nikki Levy, Academic Press. p. 284. ISBN 978-0-12-372540-0.CS1 maint: Extra text: authors list (link)
- Eichenbaum, H.; Otto, T.; Cohen, N. J. (2010). "Two functional components of the hippocampal memory system". Behavioral and Brain Sciences. 17 (3): 449–472. doi:10.1017/S0140525X00035391.
- 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. PMID 8117424.
- Sutton MA, Masters SE, Bagnall MW, Carew TJ (July 2001). "Molecular mechanisms underlying a unique intermediate phase of memory in aplysia". Neuron. 31 (1): 143–54. doi:10.1016/S0896-6273(01)00342-7. PMID 11498057.
- Parvez K, Stewart O, Sangha S, Lukowiak K (April 2005). "Boosting intermediate-term into long-term memory". The Journal of Experimental Biology. 208 (Pt 8): 1525–36. doi:10.1242/jeb.01545. PMID 15802676.
- Sutton MA, Bagnall MW, Sharma SK, Shobe J, Carew TJ (April 2004). "Intermediate-term memory for site-specific sensitization in aplysia is maintained by persistent activation of protein kinase C". The Journal of Neuroscience. 24 (14): 3600–9. doi:10.1523/JNEUROSCI.1134-03.2004. PMID 15071108.
- Stough S, Shobe JL, Carew TJ (December 2006). "Intermediate-term processes in memory formation". Current Opinion in Neurobiology. 16 (6): 672–8. doi:10.1016/j.conb.2006.10.009. PMID 17097872.
- Sutton MA, Ide J, Masters SE, Carew TJ (2002). "Interaction between amount and pattern of training in the induction of intermediate- and long-term memory for sensitization in aplysia". Learning & Memory. 9 (1): 29–40. doi:10.1101/lm.44802. PMC 155928. PMID 11917004.
- Sharma, S. K.; Bagnall, M. W.; Sutton, M. A.; Carew, T. J. (2003). "Inhibition of calcineurin facilitates the induction of memory for sensitization in Aplysia: Requirement of mitogen-activated protein kinase". Proceedings of the National Academy of Sciences. 100 (8): 4861–4866. doi:10.1073/pnas.0830994100. PMC 153646. PMID 12672952.
- Sutton MA, Schuman EM (October 2006). "Dendritic protein synthesis, synaptic plasticity, and memory". Cell. 127 (1): 49–58. doi:10.1016/j.cell.2006.09.014. PMID 17018276.
- Zhao Y, Leal K, Abi-Farah C, Martin KC, Sossin WS, Klein M (August 2006). "Isoform specificity of PKC translocation in living Aplysia sensory neurons and a role for Ca2+-dependent PKC APL I in the induction of intermediate-term facilitation". The Journal of Neuroscience. 26 (34): 8847–56. doi:10.1523/JNEUROSCI.1919-06.2006. PMID 16928874.
- Michel M, Green CL, Gardner JS, Organ CL, Lyons LC (March 2012). "Massed training-induced intermediate-term operant memory in aplysia requires protein synthesis and multiple persistent kinase cascades". The Journal of Neuroscience. 32 (13): 4581–91. doi:10.1523/JNEUROSCI.6264-11.2012. PMC 3329157. PMID 22457504.
- Antonov I, Kandel ER, Hawkins RD (April 2010). "Presynaptic and postsynaptic mechanisms of synaptic plasticity and metaplasticity during intermediate-term memory formation in Aplysia". The Journal of Neuroscience. 30 (16): 5781–91. doi:10.1523/JNEUROSCI.4947-09.2010. PMID 20410130.
- Michel M, Gardner JS, Green CL, Organ CL, Lyons LC (March 2013). "Protein phosphatase-dependent circadian regulation of intermediate-term associative memory". The Journal of Neuroscience. 33 (10): 4605–13. doi:10.1523/JNEUROSCI.4534-12.2013. PMC 3723391. PMID 23467376.
- Sutton MA, Carew TJ (April 2000). "Parallel molecular pathways mediate expression of distinct forms of intermediate-term facilitation at tail sensory-motor synapses in Aplysia". Neuron. 26 (1): 219–31. doi:10.1016/S0896-6273(00)81152-6. PMID 10798406.
- 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. PMID 16903862.
- Zhang L, Ouyang M, Ganellin CR, Thomas SA (March 2013). "The slow afterhyperpolarization: a target of β1-adrenergic signaling in hippocampus-dependent memory retrieval". The Journal of Neuroscience. 33 (11): 5006–16. doi:10.1523/JNEUROSCI.3834-12.2013. PMC 3632069. PMID 23486971.
- 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. PMID 21757019.