Afferent innervation influences HVA Ca2+ current expression in cultured neocortical neurones.
Voltage-activated Ca2+ channels represent a major pathway of Ca2+ entry into neurones. The regulation of the expression of functional Ca2+ channels thus plays a central role in neuronal differentiation. To study the influence of afferent innervation on Ca2+ current expression, we compared HVA Ca2+ currents in two categories of cultured neocortical neurones that showed pronounced differences in synaptic innervation density. Neurones strongly innervated by a presynaptic explant had a two-fold greater HVA Ca2+ current density than neurones not innervated by explant fibres. Chronic blockade of synaptic activity did not affect HVA Ca2+ current density in innervated neurones. Our results thus suggest an activity-independent regulation of HVA Ca2+ current expression by afferent innervation.
Werner
M
M
Lehrstuhl für Zellphysiologie, Ruhr-Universität Bochum, Germany.
Hatt
H
H
Gottmann
K
K
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D002478:Cells, Cultured; D019706:Excitatory Postsynaptic Potentials; D019579:Neocortex / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats
D015220:Calcium Channels