Cellular and molecular bases of memory: synaptic and neuronal plasticity.
Discoveries made during the past decade have greatly improved our understanding of how the nervous system functions. This review article examines the relation between memory and the cellular mechanisms of neuronal and synaptic plasticity in the central nervous system. Evidence indicating that activity-dependent short- and long-term changes in strength of synaptic transmission are important for memory processes is examined. Focus is placed on one model of synaptic plasticity called long-term potentiation, and its similarities with memory processes are illustrated. Recent studies show that the regulation of synaptic strength is bidirectional (e.g., synaptic potentiation or depression). Mechanisms involving intracellular signaling pathways that regulate synaptic strength are described, and the specific roles of calcium, protein kinases, protein phosphatases, and retrograde messengers are emphasized. Evidence suggests that changes in synaptic ultrastructure, dendritic ultrastructure, and neuronal gene expression may also contribute to mechanisms of synaptic plasticity. Also discussed are recent findings about postsynaptic mechanisms that regulate short-term synaptic facilitation and neuronal burst-pattern activity, as well as evidence about the subcellular location (presynaptic or postsynaptic) of mechanisms involved in long-term synaptic plasticity.
Wang
J H
JH
Department of Neurobiology and Anatomy, University of Texas Medical School-Houston, 77225, U.S.A.
Ko
G Y
GY
Kelly
P T
PT
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002118:Calcium / Q000502:physiology; D015220:Calcium Channels / Q000737:chemistry / Q000502:physiology; D006624:Hippocampus / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology; D017774:Long-Term Potentiation / Q000502:physiology; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D008954:Models, Biological; D009473:Neuronal Plasticity / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology; D019580:Perforant Pathway / Q000033:anatomy & histology / Q000502:physiology; D010749:Phosphoprotein Phosphatases / Q000502:physiology; D011494:Protein Kinases / Q000502:physiology; D013569:Synapses / Q000737:chemistry / Q000502:physiology*; D009435:Synaptic Transmission
D015220:Calcium Channels; D009569:Nitric Oxide; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases; D002118:Calcium