LOXL null mice demonstrate selective dentate structural changes but maintain dentate granule cell and CA1 pyramidal cell potentiation in the hippocampus

Neurosci Lett. 2005 Dec 23;390(2):118-22. doi: 10.1016/j.neulet.2005.08.021.


Lysyl oxidase-like protein (LOXL), part of the lysyl oxidase copper-dependent amine oxidase family, is expressed in the extracellular matrix and in the nucleus. It likely plays a role in cross-linking collagen and elastin, possibly modulating cellular functions. Immunohistochemical studies show the presence of LOXL in the pyramidal cell layer of the hippocampus; and in this study, we report that cells in the granule cell layer have significantly smaller somas in LOXL -/- compared to LOXL +/+ mice. In addition we tested the hypothesis that these structural alterations in the dentate granule layer were associated with synaptic efficacy and thus muted long-term potentiation in mice lacking the protein. Electrical recordings were obtained in 300-mum hippocampal slices in dentate and CA1 pyramidal cell layers in age-matched wild type and LOXL null mice. Potentiation in the CA1 cell layer of 10 LOXL -/- and 8 LOXL +/+ mice was 191.0+/-9.3% and 181.6+/-9.1%, respectively (mean+/-S.E.M.). Dentate potentiation was 120.8+/-7.0% and 121.0+/-3.4% in 11 LOXL -/- and 11 LOXL +/+ mice, respectively. No phenotypic difference in potentiation of population spike amplitude (or in EPSP slope) in either layer was observed. Thus, contrary to expectation, structural changes in the hippocampus of LOXL -/- mice did not affect synaptic remodeling in a manner that impaired the establishment of LTP.

Publication types

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

MeSH terms

  • Amino Acid Oxidoreductases / genetics
  • Amino Acid Oxidoreductases / metabolism*
  • Animals
  • Cell Shape
  • Dentate Gyrus / cytology*
  • Electrophysiology
  • Female
  • Hippocampus / cytology*
  • Hippocampus / metabolism
  • Long-Term Potentiation / physiology*
  • Male
  • Mice
  • Mice, Knockout
  • Neurons / cytology*
  • Neurons / physiology*
  • Pyramidal Cells / physiology*
  • Synaptic Transmission / physiology


  • Amino Acid Oxidoreductases
  • Loxl1 protein, mouse