Activation of kinetically distinct synaptic conductances on inhibitory interneurons by electrotonically overlapping afferents

Neuron. 2002 Jul 3;35(1):161-71. doi: 10.1016/s0896-6273(02)00734-1.

Abstract

Mossy fiber (MF) and CA3 collateral (CL) axons activate common interneurons via synapses comprised of different AMPA receptors to provide feedforward and feedback inhibitory control of the CA3 hippocampal network. Because synapses potentially occur over variable electrotonic distances that distort somatically recorded synaptic currents, it is not known whether the underlying afferent-specific synaptic conductances are associated with different time courses. Using a somatic voltage jump technique to alter the driving force at the site of the synapse, we demonstrate that MF and CL synapses overlap in electrotonic location yet differ in conductance time course. Thus, afferent-specific conductance time courses allow single interneurons to differentially integrate feedforward and feedback information without the need to segregate distinct AMPA receptor subunits to different electrotonic domains.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Afferent Pathways / cytology
  • Afferent Pathways / metabolism
  • Animals
  • Dendrites / metabolism
  • Dendrites / ultrastructure
  • Electric Stimulation
  • Excitatory Postsynaptic Potentials / physiology*
  • Feedback / physiology
  • Interneurons / cytology
  • Interneurons / metabolism*
  • Kinetics
  • Mossy Fibers, Hippocampal / metabolism*
  • Mossy Fibers, Hippocampal / ultrastructure
  • Nerve Net / metabolism
  • Nerve Net / ultrastructure
  • Neural Conduction / physiology
  • Neural Inhibition / physiology*
  • Organ Culture Techniques
  • Rats
  • Reaction Time / physiology
  • Receptors, AMPA / metabolism*
  • Synapses / metabolism*
  • Synapses / ultrastructure
  • Synaptic Transmission / physiology*
  • Time Factors

Substances

  • Receptors, AMPA