Developmental regulation of action potential-induced Ca2+ entry in neocortical neurons.
Intracellular calcium plays a critical role in the regulation of membrane excitability, synaptic integration and synaptic plasticity. Using whole-cell recording and calcium imaging, we investigated intracellular calcium dynamics in apical dendrites of layer V pyramidal cells in the immature rat neocortex. Dendritic calcium increases induced by action potentials were only small on postnatal days 4-6 (P4-6), then underwent a gradual enhancement during the second post-natal week and were 2- to 3-fold larger on P16-18 than on P4-6. At P15-18 there were no significant differences in the calcium increases among the three subclasses of layer V pyramidal neurons: adapting regular spiking (RS), non-adapting RS and intrinsically bursting (IB) neurons. Developmental regulation of dendritic calcium dynamics may be crucial for functional maturation of the neocortex.
Isomura
Y
Y
Department of Integrative Brain Science, Graduate School of Medicine, Kyoto University, Japan.
Hashimoto
K
K
Yamamoto
K
K
Kato
N
N
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism; D005456:Fluorescent Dyes; D016257:Fura-2; D019579:Neocortex / Q000166:cytology* / Q000254:growth & development*; D018408:Patch-Clamp Techniques; D010507:Periodicity; D017966:Pyramidal Cells / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar
D005456:Fluorescent Dyes; D002118:Calcium; D016257:Fura-2