Developmental regulation of T-, N- and L-type calcium currents in mouse embryonic sensory neurones

Eur J Neurosci. 1998 Feb;10(2):545-52. doi: 10.1046/j.1460-9568.1998.00055.x.


We investigated the development of a low (T-type) and two high voltage-activated (N- and L-type) calcium channel currents in large diameter dorsal root ganglion neurones acutely isolated from embryonic mice using the whole-cell patch-clamp technique. The low and high voltage-activated barium currents (LVA and HVA) were identified by their distinct threshold of activation and their sensitivity to pharmacological agents, dihydropyridines and omega-conotoxin-GVIA, at embryonic day 13 (E13), E15 and E17-18, respectively, before, during and after synaptogenesis. The amplitude and density of LVA currents, measured during a -40 mV pulse from a holding potential of -100 mV, increased significantly between E13 and E15, and remained constant between E15 and E17-18. The density of global HVA current, elicited by 0 mV pulse, increased between E13 and E15/E17-18. The density of the N-type current studied by the application of omega-conotoxin-GVIA (1 microM) increased significantly between E13 and E15/E17-18. The use of the dihydropyridine nitrendipine (1 microM) revealed that the density of L-type current remained constant at each stage of development. Nevertheless, application of dihydropyridine Bay K 8644 (3 microM) demonstrated a significant slowing of the deactivation tail current between embryonic days 13 and 15, which may reflect a qualitative maturation of this class of calcium channel current. The temporal relationship between the changes in calcium channel pattern and the period of target innervation suggests possible roles of T-, N- and L-type currents during developmental key events such as natural neurone death and onset of synapse formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium Channel Agonists / pharmacology
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / drug effects
  • Calcium Channels / metabolism*
  • Electric Stimulation
  • Electrophysiology
  • Ganglia, Spinal / cytology
  • Ganglia, Spinal / drug effects
  • Ganglia, Spinal / embryology
  • Ion Channel Gating / drug effects
  • Ion Channel Gating / physiology
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Mice
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / metabolism*
  • Patch-Clamp Techniques
  • Spinal Cord / cytology
  • Spinal Cord / embryology*
  • Spinal Cord / metabolism


  • Calcium Channel Agonists
  • Calcium Channel Blockers
  • Calcium Channels