Membrane Properties and Synaptic Connectivity of Fast-Spiking Interneurons in Rat Ventral Striatum

Brain Res. 2007 Jun 4;1152:49-56. doi: 10.1016/j.brainres.2007.03.053. Epub 2007 Mar 24.

Abstract

In vitro patch-clamp recordings were made to study the membrane properties and synaptic connectivity of fast-spiking interneurons in rat ventral striatum. Using a whole-cell configuration in acutely prepared slices, fast-spiking interneurons were recognized based on their firing properties and their morphological phenotype was confirmed by immunocytochemistry. Membrane properties of fast-spiking interneurons were distinguished from those of medium-sized spiny neurons by their more depolarized resting membrane potential, lower action potential amplitude and shorter half-width, short spike repolarization time and deep spike afterhyperpolarization. Firing patterns of interneurons could be subdivided in a bursting and non-bursting mode. Simultaneous dual whole-cell recordings revealed a high degree of connectivity of fast-spiking interneurons to medium-sized spiny neurons via unidirectional synapses. Burst firing in fast-spiking interneurons that were presynaptic to medium-sized spiny neurons resulted in barrages of postsynaptic potentials showing an initial amplitude increment, rapidly followed by a decrement. In conclusion, ventral striatal fast-spiking interneurons can be clearly distinguished from medium-sized spiny neurons by their membrane properties and their firing patterns can be subdivided in bursting and non-bursting modes. Their synaptic connectivity to medium-sized spiny neurons is unidirectional and characterized by frequency-dependent, dynamic changes in postsynaptic amplitude.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials*
  • Animals
  • Basal Ganglia / physiology*
  • Cell Membrane / physiology
  • Interneurons / physiology*
  • Patch-Clamp Techniques
  • Rats
  • Rats, Wistar
  • Synaptic Transmission*