Neurotensin type 2 receptor is involved in fear memory in mice

J Neurochem. 2007 Sep;102(5):1669-1676. doi: 10.1111/j.1471-4159.2007.04805.x.


Neurotensin receptor subtype 2 (Ntsr2) is a levocabastine-sensitive neurotensin receptor expressed diffusely throughout the mouse brain. Previously, we found that Ntsr2-deficient mice have an abnormality in the processing of thermal nociception. In this study, to examine the involvement of Ntsr2 in mouse behavior, we performed a fear-conditioning test in Ntsr2-deficient mice. In the contextual fear-conditioning test, the freezing response was significantly reduced in Ntsr2-deficient mice compared with that of wild-type mice. This reduction was observed from 1 h to 3 weeks after conditioning, and neither shock sensitivity nor locomotor activity was altered in Ntsr2-deficient mice. In addition, we found that Ntsr2 mRNA was predominantly expressed in cultured astrocytes and weakly expressed in cultured neurons derived from mouse brain. The combination of in situ hybridization and immunohistochemistry showed that Ntsr2 mRNA was dominantly expressed in glial fibrillary acidic protein positive cells in many brain regions including the hypothalamus, while Ntsr2 gene was co-expressed with neuron-specific microtubule associated protein-2 in limited numbers of cells. These results suggest that Ntsr2 in astrocytes and neurons may have unique function like a modulation of fear memory in the mouse brain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation / adverse effects
  • Animals
  • Behavior, Animal / physiology
  • Cells, Cultured
  • Conditioning, Classical / physiology
  • Embryo, Mammalian
  • Fear*
  • Freezing Reaction, Cataleptic / physiology
  • Glial Fibrillary Acidic Protein / metabolism
  • In Situ Hybridization / methods
  • Male
  • Memory / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microtubule-Associated Proteins / metabolism
  • Motor Activity / genetics
  • Neuroglia / metabolism
  • Neurons / metabolism
  • Receptors, Neurotensin / deficiency
  • Receptors, Neurotensin / physiology*
  • Time Factors


  • Glial Fibrillary Acidic Protein
  • Microtubule-Associated Proteins
  • Mtap2 protein, mouse
  • Ntsr2 protein, mouse
  • Receptors, Neurotensin