|MadSci Network: Neuroscience|
The capacity of the nervous system to undergo change continues throughout life. This capacity is referred to as neural plasticity. It is thought that learning (i.e. the process by which the nervous system acquires new information) is mediated by carefully regulated changes in the strength of existing synapses. Changes in the strength of synaptic transmission between connected neurons are widely believed to underlie changes in perceptual and behavioral function experienced during development and learning. Long-term potentiation (LTP) of synaptic strength, seen widely in the central nervous system, is the dominant experimental model for use-dependent synaptic learning. The most well-studied synaptic pathway exhibiting LTP is in the hippocampal area CA1. This pathway has been implicated in the storage of declarative perceptual memories( memories that are available to the conscious mind as opposed to procedural memory which are not available to the conscious mind such as the ability to ride a bicycle) in humans and spatial learning in rodents. The most extensively studied form of LTP requires the activation of postsynaptic N-methyl-D-aspartate (NMDA) type glutamate receptors. The influx of Ca2+ ions through NMDA receptors triggers a partly understood cascade of enzyme activity which results in a long-term strengthening of the synapse. The above is a partial explanation of how we can take information and store it, in essence how we learn, at the molecular level. Namely a stimulus leads to firing of neurons and release of neurotransmitter which can bind to the NMDA-receptor and lead to Ca2+ influx and setting of a cascade that leads to LTP. How we retrieve the information later on is much more of a mystery at this point. References Neuroscience 1997 Edited by Purves et al. Published by Sinauer associates inc. Sunderland, MA.
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