Differential Expression of Intrinsic Membrane Currents in Defined Cell Types of the Anterolateral Bed Nucleus of the Stria Terminalis

J Neurophysiol. 2007 Aug;98(2):638-56. doi: 10.1152/jn.00382.2007. Epub 2007 May 30.

Abstract

The anterolateral group of the bed nucleus of the stria terminalis (BNST(ALG)) plays a critical role in a diverse array of behaviors, although little is known of the physiological properties of neurons in this region. Using whole cell patch-clamp recordings from rat BNST(ALG) slices in vitro, we describe three distinct physiological cell types. Type I neurons were characterized by the presence of a depolarizing sag in response to hyperpolarizing current injection that resembled activation of the hyperpolarization-activated cation current I(h) and a regular firing pattern in response to depolarizing current injection. Type II neurons exhibited the same depolarizing sag in response to hyperpolarizing current injection, but burst-fired in response to depolarizing current injection, which was indicative of the activation of the low-threshold calcium current I(T). Type III neurons did not exhibit a depolarizing sag in response to hyperpolarizing current injection, but instead exhibited a fast time-independent rectification that became more pronounced with increased amplitude of hyperpolarizing current injection, and was indicative of activation of the inwardly rectifying potassium current I(K(IR)). Type III neurons also exhibited a regular firing pattern in response to depolarizing current. Using voltage-clamp analysis we further characterized the primary active currents that shaped the physiological properties of these distinct cell types, including I(h), I(T), I(K(IR)), the voltage-dependent potassium current I(A), and the persistent sodium current I(NaP). The functional relevance of each cell type is discussed in relation to prior anatomical studies, as well as how these currents may interact to modulate neuronal activity within the BNST(ALG).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 4-Aminopyridine / pharmacology
  • Aging / physiology
  • Animals
  • Benzylamines / pharmacology
  • Dose-Response Relationship, Radiation
  • Electric Stimulation / methods
  • Excitatory Amino Acid Antagonists / pharmacology
  • GABA Agents / pharmacology
  • In Vitro Techniques
  • Male
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology*
  • Membrane Potentials / radiation effects
  • Neurons / classification*
  • Neurons / drug effects
  • Neurons / physiology*
  • Neurons / radiation effects
  • Patch-Clamp Techniques / methods
  • Phosphinic Acids / pharmacology
  • Potassium Channel Blockers / pharmacology
  • Quinoxalines / pharmacology
  • Rats
  • Septal Nuclei / cytology*
  • Sodium Channel Blockers / pharmacology
  • Tetraethylammonium / pharmacology
  • Tetrodotoxin / pharmacology

Substances

  • Benzylamines
  • Excitatory Amino Acid Antagonists
  • GABA Agents
  • Phosphinic Acids
  • Potassium Channel Blockers
  • Quinoxalines
  • Sodium Channel Blockers
  • CGP 52432
  • Tetrodotoxin
  • FG 9041
  • Tetraethylammonium
  • 4-Aminopyridine