Using immunocytochemical assays and patch-clamp and calcium-imaging recordings, we demonstrate that L-type and N-type calcium channels have distinct patterns of expression and distribution and play different functional roles during hippocampal neuron differentiation. L-type channels, which support the depolarization-induced calcium influx in neurons from the very early developmental stages, are functionally restricted to the somatodendritic compartment throughout neuronal development and play a crucial role in supporting neurite outgrowth at early developmental stages. N-type channels, which start contributing at later neuronal differentiation stages (3-4 DIV), are also functionally expressed in the axons of immature neurons. At this developmental stage preceding synaptogenesis, N-type (but not L-type) channels are involved in controlling synaptic vesicle recycling. It is only at later developmental stages (10-12 DIV), when the neurons have established a clear axodendritic polarity and form synaptic contacts, that N-type channels are progressively excluded from the axon. Electrophysiological recordings of single neurons growing in microislands revealed that synaptic maturation coincides with a progressive increase in N-type channels in the somatodendritic region and a progressive decrease in the N-type channels supporting glutamate release from the presynaptic terminal. These results indicate that L-type and N-type calcium channels undergo dynamic, developmentally regulated rearrangements in regional distribution and function and also suggest that different mechanisms may be involved in the sorting and/or stabilization of these two types of channels in different plasma membrane domains during neuronal differentiation. Copyright 2000 Academic Press.
Titolo: | Different localizations and functions of L-type and N-type calcium channels during development of hippocampal neurons |
Autori: | PRAVETTONI, ELENA (Primo) BACCI, ALBERTO LUIGI (Secondo) MATTEOLI, MICHELA (Penultimo) |
Parole Chiave: | ω-conotoxin-GVIA; Calcium channels; Hippocampal neurons; Neuronal polarity; Nifedipine; Synaptogenesis |
Data di pubblicazione: | 15-nov-2000 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | 10.1006/dbio.2000.9872 |
Appare nelle tipologie: | 01 - Articolo su periodico |