Acute stress and chronic stress change brain-derived neurotrophic factor (BDNF) and tyrosine kinase-coupled receptor (TrkB) expression in both young and aged rat hippocampus.
OBJECTIVE
The purpose of this study is to explore the dynamic change of brainderived neurotrophic factor (BDNF) mRNA, protein, and tyrosine kinase-coupled receptor (TrkB) mRNA of the rat hippocampus under different stress conditions and to explore the influence of senescence on the productions expression.


METHODS
By using forced-swimming in 4 degrees C cold ice water and 25 degrees C warm water, young and aged male rats were randomly divided into acute stress (AS) and chronic mild repeated stress (CMRS) subgroups, respectively. BDNF productions and TrkB mRNA in the hippocampus were detected by using Western-blotting and reverse transcription-polymerase chain reaction (RT-PCR), separately, at 15, 30, 60, 180, and 720 min after the last stress session.


RESULTS
The short AS induced a significant increase in BDNF mRNA and protein in both age groups, but the changes in the young group were substantially greater than those of the aged group (p < 0.005). The CMRS resulted in a decrease in BDNF mRNA and protein, but a significant increase in TrkB mRNA in both young and age groups. The expression of BDNF mRNA and protein in the AS groups were higher than in the CMRS groups at 15, 30, and 60 min after stress.


CONCLUSIONS
The results indicated that the up/down-regulation of BDNF and TrkB were affected by aging and the stimulus paradigm, which might reflect important mechanisms by which the hippocampus copes with stressful stimuli.
Shi
Shou-Sen
SS
Department of Medical Psychology, Institute of Biochemistry and Molecular Biology, Binzhou Medical University, Yantai, Shandong, China.
Shao
Shu-Hong
SH
Yuan
Bang-Ping
BP
Pan
Fang
F
Li
Zun-Ling
ZL
D000818:Animals; D015153:Blotting, Western; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D003345:Corticosterone / Q000097:blood; D005786:Gene Expression Regulation; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D011863:Radioimmunoassay; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D020813:Receptor, trkB / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013312:Stress, Physiological / Q000235:genetics / Q000502:physiology*
D019208:Brain-Derived Neurotrophic Factor; D020813:Receptor, trkB; D003345:Corticosterone