Relationship between Circadian Clock Genes and the Neurotrophic Factor Genes in Rat Hippocampus
Ratchadaporn Pramong PhD*, Piyarat Govitrapong PhD**,***, Pansiri Phansuwan-Pujito PhD*
Affiliation : * Department of Anatomy, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand ** Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Nakornpathom, Thailand *** Chulabhorn Royal Academy, Chulabhorn Graduate Institute, Bangkok, Thailand
Background : The hippocampus, a key brain area for learning and memory, can express clock genes with circadian fashion.
The neurotrophic factors are important for cognitive function in the hippocampus. The expression of circadian clock gene and
neurotrophic factor in the hippocampus would be necessary to achieve and optimize daily memory performance.
Objective : It is of interest to examine the daily expression patterns of neurotrophic factor genes and the link between these
genes and clock genes in rat hippocampus.
Material and Method: Daily expression profiles of four clock genes (Per1, Cry1, Bmal1, and Rev-erb alpha) and four
neurotrophic factor genes (BDNF, NGF, NT-3, and VEGF) were analyzed in the rat hippocampus at 6 hours apart by real-time
PCR.
Results : The mRNAs of BDNF, NGF, and VEGF, but not NT-3 in hippocampus were expressed in circadian manner as well as
those of clock genes. Correlation analysis revealed strong relationships between the expression of VEGF and Per1, VEGF
and Rev-erb alpha, BDNF and Bmal1, and BDNF and Cry1.
Conclusion : The present study suggests that VEGF and BDNF are clock-controlled genes relating to specific clock genes.
Therefore, further investigation on the molecular mechanisms linking cognitive processes and circadian clock in hippocampus
could be necessary to clarify their functions.
Keywords : Hippocampus, Clock genes, Neurotrophic factors, BDNF, NGF, NT-3, VEGF, Circadian
