Regional changes in the expression of neurotrophic factors and their receptors following acute traumatic brain injury in the adult rat brain

We have analyzed the effect of severe traumatic brain injury (TBI) on the l evels of mRNA expression of neurotrophic factors (NTFs): brain-derived neur otrophic factor (BDNF), nerve growth factor (NGF), ciliary neurotrophic fac tor (CNTF) and their respective receptors: trkB, trkA and CNTFR alpha. The expression was examined in the region of the lesion as well as a region rem ote from the lesion at 12, 24, and 36 h following the injury. Our data sugg est that after the brain injury, the expression of NGF and BDNF mRNAs were early, transiently and significantly upregulated while that of CNTF was a s low and less amplified response in both areas of the brain. We also found t hat trkA mRNA expression was only upregulated significantly in the remote a rea; trkB mRNA showed no significant change in either area except an upregu lation at 12 h in the remote area. CNTFR alpha was downregulated significan tly by 24-36 h in the lesion area and by 24 h in the remote area. These cha nges suggest that TBI regulates the expression of NTFs and their receptors. These alterations in expression may be involved in modulating the neuronal response after brain injury. (C) 1999 Elsevier Science B.V. All rights res erved.