BDNF and trkB mRNAs oscillate in rat brain during the light-dark cycle

Brain Res Mol Brain Res. 1998 Jun 15;57(2):321-4. doi: 10.1016/s0169-328x(98)00092-8.


In this study, we investigated whether in basal conditions the different functional states occurring during a 24-h cycle are reflected by the expression of brain-derived neurotrophic factor (BDNF) and its receptor, trkB, in rat cerebral cortex and hippocampus. Using semiquantitative RT-PCR assay, the levels of both BDNF and trkB mRNAs were found to undergo significant variation in a 24-h period. The strongest variation was detected in the hippocampus, where the ratio between maximum and minimum levels was about 3.5 and 17.5 for BDNF and trkB, respectively. These findings provide the first evidence that, in the absence of any experimental manipulation, the expression of a neurotrophin and its receptor undergoes diurnal oscillation, possibly related to the physiological variations of the activity level.

MeSH terms

  • Animals
  • Brain-Derived Neurotrophic Factor / genetics*
  • Circadian Rhythm / physiology*
  • Darkness
  • Frontal Lobe / metabolism*
  • Hippocampus / metabolism*
  • Light
  • Male
  • Oscillometry
  • Rats
  • Rats, Wistar
  • Receptor Protein-Tyrosine Kinases / genetics*
  • Receptor, Ciliary Neurotrophic Factor
  • Receptors, Nerve Growth Factor / genetics*


  • Brain-Derived Neurotrophic Factor
  • Receptor, Ciliary Neurotrophic Factor
  • Receptors, Nerve Growth Factor
  • Receptor Protein-Tyrosine Kinases