Nucleus reuniens thalami innervates gamma aminobutyric acid positive cells in hippocampal field CA1 of the rat

Neurosci Lett. 2000 Jan 14;278(3):145-8. doi: 10.1016/s0304-3940(99)00935-0.


The aim of the present study was to investigate whether the nucleus reuniens thalami (RE) innervates inhibitory cells in hippocampal field CA1. Therefore, we examined the RE-CA1 input at the ultrastructural level. RE axons were anterogradely labeled with biotin-conjugated dextran amine (BDA), in combination with pre-embedding gamma aminobutyric acid (GABA)-immunolabeling of neurons in CA1. We observed that part of the BDA-labeled axons formed asymmetrical (i.e. excitatory) synapses on GABA-positive dendrites. Based on these data, which are in line with our previously published electrophysiological observations (Dolleman-Van der Weel, M.J., Lopes da Silva, F.H. and Witter, M.P., Nucleus reuniens thalami modulates activity in hippocampal field CA1 through excitatory and inhibitory mechanisms. J. Neurosci., 17 (1997) 5640-5650), we propose that RE-CA1 input partially influences hippocampal transmission through activation of local inhibitory interneurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / physiology
  • Biotin / analogs & derivatives
  • Dendrites / metabolism
  • Dendrites / physiology
  • Dextrans
  • Female
  • Fluorescent Dyes
  • Hippocampus / cytology
  • Hippocampus / metabolism
  • Hippocampus / physiology*
  • Neural Inhibition / physiology
  • Neurons / physiology
  • Rats
  • Rats, Wistar
  • Synapses / physiology
  • Thalamic Nuclei / physiology*
  • gamma-Aminobutyric Acid / metabolism*


  • Dextrans
  • Fluorescent Dyes
  • biotinylated dextran amine
  • gamma-Aminobutyric Acid
  • Biotin