2001, Number 2
Salud Mental 2001; 24 (2)
Leff P, Romo-Parra H, Medécigo M, Gutiérrez R, Anton B
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ABSTRACTPlasticity of the nervous system has been related to learning and memory processing as early as the beginning of the century; although, remotely, brain plasticity in relation to behavior has been connoted over the past two centuries. However, four decades ago, several vidences have shown that experience and training induce neural changes, showing that major neuroanatomical, neurochemical as well as molecular changes are required for the establishment of a long-term memory process. Early experimental procedures showed that differential experience, training and/or informal experience could produce altered quantified changes in the brain of mammals. Moreover, neuropsychologists have emphasized that different memories could be localized in separate cortical areas of the brain, but updated evidences assert that memory systems are specifically distributed in exclusive neural networks in the cortex. For instance, the same cortical systems that lead us to perceive and move in our environment, are used as neural subs trates for memory retrieval. Such memories are the result of the repeated activity of millions of neurons assembled into distinct neural networks, where plastic changes in synaptic function leads to the strengthening of the same synaptic connections with the result of reconstructed permanent traces that lead to remembrance (Hebb Postulate). Elementary forms of learning and memory have been studied in simple neural systems of invertebrates, and as such have led the way for understanding much of the electrophysiological and neurochemical events occurring during LTP. Long-term potentiation (LTP) is the result of the increase in the strength of synaptic transmission, lasting as long as can be measured from hours to days. LTP has been detected in several areas of the brain, particularly, in the hippocampus, amygdala, and cortex, including several related limbic structures in the mammalian brain. LTP represents up to date the best model available for understanding the cellular basis of learning and memory in the central nervous system of mammals including humans.