title: Transient expansion of synaptically connected dendritic spines upon induction of hippocampal long-term potentiation.
abstract: Dendritic spines are small protrusions from dendritic shafts that contain the postsynaptic sites of glutamatergic synapses in the brain. Spines undergo dramatic activity-dependent structural changes that are particularly prominent during neuronal development. Although changes in spine shape or number have been proposed to contribute to forms of synaptic plasticity that underlie learning and memory, the extent to which spines remain plastic in the adult brain is unclear. We find that induction of long-term potentiation (LTP) of synaptic transmission in acute hippocampal slices of adult mice evokes a reliable, transient expansion in spines that are synaptically activated, as determined with calcium imaging. Similar to LTP, transient spine expansion requires N-methyl-D-aspartate (NMDA) receptor-mediated Ca2+ influx and actin polymerization. Moreover, like the early phase of LTP induced by the stimulation protocol, spine expansion does not require Ca2+ influx through L-type voltage-gated Ca2+ channels nor does it require protein synthesis. Thus, transient spine expansion is a characteristic feature of the initial phases of plasticity at mature synapses and so may contribute to synapse remodeling important for LTP.
authors.affiliation: Center for Neurobiology and Behavior, Department of Pharmacology, Columbia University, 1051 Riverside Drive, New York, NY 10032, USA.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Lang
authors.forename: Angel
authors.initials: A
authors.lastname: Barco
authors.forename: Leonard
authors.initials: L
authors.lastname: Zablow
authors.forename: Eric R
authors.initials: ER
authors.lastname: Kandel
authors.forename: Steven A
authors.initials: SA
authors.lastname: Siegelbaum
authors.forename: Stanislav S
authors.initials: SS
authors.lastname: Zakharenko
mesh_terms: D000818:Animals; D020746:Calcium Channels, L-Type / Q000502:physiology; D020013:Calcium Signaling; D003712:Dendrites / Q000502:physiology*; D004558:Electric Stimulation; D049452:Green Fluorescent Proteins / Q000235:genetics; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D017966:Pyramidal Cells / Q000502:physiology; D011994:Recombinant Proteins / Q000235:genetics; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission
chemical_list: D020746:Calcium Channels, L-Type; D011994:Recombinant Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins