Calcium channel gating and modulation by transmitters depend on cellular compartmentalization

Nat Neurosci. 2000 Jul;3(7):670-8. doi: 10.1038/76621.

Abstract

Voltage-gated Ca2+ channels participate in dendritic integration, yet functional properties of Ca2+ channels and mechanisms of their modulation by neurotransmitters in dendrites are unknown. Here we report how pharmacologically identified Ca2+ channels behave in different neural compartments. Whole-cell and cell-attached patch-clamp recordings were made on both cell bodies and electrically isolated dendrites of sympathetic neurons. We found not only that Ca2+ channel populations differentially contribute to somatic and dendritic currents but also that families of Ca2+ channels display gating properties and neurotransmitter modulation that depend on channel compartmentalization. By comparison with their somatic counterparts, dendritic N-type Ca2+ currents were hypersensitive to neurotransmitters and G proteins. Single-channel analysis showed that dendrites express a unique N-type channel that has enhanced interaction with Gbetagamma. Thus Ca2+ channels in dendrites seem to be specialized elements with unique regulatory mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium Channels, N-Type / physiology*
  • Cells, Cultured
  • Dendrites / physiology
  • GTP-Binding Proteins / physiology
  • Ion Channel Gating / physiology
  • Kinetics
  • Membrane Potentials
  • Neurites / physiology
  • Neurons / physiology*
  • Neurotransmitter Agents / physiology*
  • Patch-Clamp Techniques
  • Rats
  • Superior Cervical Ganglion / physiology

Substances

  • Calcium Channels, N-Type
  • Neurotransmitter Agents
  • GTP-Binding Proteins