Postsynaptic signaling networks: cellular cogwheels underlying long-term plasticity.
Learning depends on positive or negative changes in synaptic transmission that are synapse-specific and sustained. Synaptic signals can be directly measured and respond to certain kinds of stimulation by becoming persistently enhanced (long-term potentiation, LTP) or decreased (long-term depression, LTD). Studying LTP and LTD opens a window on to the molecular mechanisms of memory. Although changes in both pre- and postsynaptic strength have been implicated in LTP and LTD, most attention has been focused on changes in postsynaptic glutamate receptor density. This is controlled by intracellular Ca(2+) ions via a network of signaling molecules. Changes in postsynaptic Ca(2+) concentration depend on the coincidence of appropriate synaptic signals, as is found in learning situations. The long-term persistence of LTP and LTD requires gene transcription and translation. It is posited that local translation at the synapse, in a self-sustaining manner, mediates the persistence of long-term changes despite constant turnover of the synaptic components.
Blitzer
Robert D
RD
Department of Psychiatry, Mount Sinai School of Medicine, New York, New York 10029, USA.
Iyengar
Ravi
R
Landau
Emmanuel M
EM
D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D003712:Dendrites / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D006801:Humans; D007858:Learning / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D014176:Protein Biosynthesis / Q000502:physiology; D017470:Receptors, Glutamate / Q000378:metabolism; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology
D017470:Receptors, Glutamate; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases