Expression of Brain-Derived Neurotrophic Factor and its mRNA in Catecholaminergic Neurons of the Rat Lower Brainstem after Colohicine Treatment or Hemorrhage / 대한해부학회지

ABSTRACT

Widespread brain-derived neurotrophic factor (BDNF) mRNA expression has been detected in the region of catecholamine groups of the rat lower brainstem, while few BDNF-immunoreactive cells were found in this area. In the present study, a double-color immunofluorescence (IF) technique for BDNF and tyrosine hydroxylase (TH) after colchicine treatment was employed to evaluate the possible presence of BDNF immunoreactivity in the catecholamin-ergic cells of rat lower brainstem. Additionally, a double-color IF technique for BNDF and TH and in situ hybridiza-tion for BDNF mRNA were performed to see effects of hemorrhage on the expression of BDNF and its mRNA. We detected many new BDNF-immunoreactive cells in the A1, A2, A4, A6-A10 and C1-C3 cell groups and in the other lower brainstem nuclei where, without colchicine treatment, BDNF mRNA was expressed, but not BDNF immunoreactivity. In addition, the catecholaminergic neurons were found to express BDNF immunoreactivity with the co-existence being greatest, in percentage terms, in medullary catecholaminergic cell groups. Hypotensive hemorrhage, which activates medullary catecholaminergic neurons, induced the expression of BDNF immunoreactivity in catecholaminergic neurons (A1/C1 and C2) and increased the number of BDNF mRNA-containing neurons in the area. These results demonstrate that BDNF is regulated by activity in medullary catecholaminergic cell groups involved in central cardiovascular regulation.