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Hebbian theory is a neuropsychological theory claiming that an increase in synaptic efficacy arises from a presynaptic cell's repeated and persistent stimulation of a postsynaptic cell. It is an attempt to explain synaptic plasticity , the adaptation of brain neurons during the learning process.
In 1973, M. M. Taylor [1] suggested that if synapses were strengthened for which a presynaptic spike occurred just before a postsynaptic spike more often than the reverse (Hebbian learning), while with the opposite timing or in the absence of a closely timed presynaptic spike, synapses were weakened (anti-Hebbian learning), the result would be an informationally efficient recoding of input ...
This second type of learning is a more rapid and insightful learning because the cell assemblies and phase sequences have already been created and now can be rearranged in any number of ways. [25] The Hebbian theory of learning implies that every experience a person encounters becomes set into the network of brain cells. Then, each time a ...
[1] Hence, it is the biological basis for learning and the formation of new memories. [ 1 ] [ 2 ] Activity-dependent plasticity is a form of neuroplasticity that arises from intrinsic or endogenous activity, as opposed to forms of neuroplasticity that arise from extrinsic or exogenous factors, such as electrical brain stimulation - or drug ...
Two molecular mechanisms for synaptic plasticity involve the NMDA and AMPA glutamate receptors. Opening of NMDA channels (which relates to the level of cellular depolarization) leads to a rise in post-synaptic Ca 2+ concentration and this has been linked to long-term potentiation, LTP (as well as to protein kinase activation); strong depolarization of the post-synaptic cell completely ...
Bienenstock–Cooper–Munro (BCM) theory, BCM synaptic modification, or the BCM rule, named after Elie Bienenstock, Leon Cooper, and Paul Munro, is a physical theory of learning in the visual cortex developed in 1981.
Homeostatic synaptic plasticity is a means of maintaining the synaptic basis for learning, respiration, and locomotion, in contrast to the Hebbian plasticity associated with learning and memory. [3] Although Hebbian forms of plasticity, such as long-term potentiation and long-term depression occur rapidly, homeostatic plasticity (which relies ...
Depressed subjects show evidence of impaired neuroplasticity (e.g. shortening and reduced complexity of dendritic trees) Anti-depressant medications may enhance neuroplasticity at both a molecular and dendritic level. The conclusion is that disrupted neuroplasticity is an underlying feature of depression, and is reversed by antidepressants. [138]