Biphasic synaptic Ca influx arising from compartmentalized electrical signals in dendritic spines.

ABSTRACT: Excitatory synapses on mammalian principal neurons are typically formed onto dendritic spines, which consist of a bulbous head separated from the parent dendrite by a thin neck. Although activation of voltage-gated channels in the spine and stimulus-evoked constriction of the spine neck can influence synaptic signals, the contribution of electrical filtering by the spine neck to basal synaptic transmission is largely unknown. Here we use spine and dendrite calcium (Ca) imaging combined with 2-photon laser photolysis of caged glutamate to assess the impact of electrical filtering imposed by the spine morphology on synaptic Ca transients. We find that in apical spines of CA1 hippocampal neurons, the spine neck creates a barrier to the propagation of current, which causes a voltage drop and r

SUBMITTER: Bloodgood BL 

PROVIDER: S-EPMC2734993 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature