1st Conference of Polish-German Cooperation Program in Neuroscience ordered by the Federal Ministry of Education and Research and the Polish Ministry of Education and Science April 21-22, 2006 in Warsaw, Poland

[A1] Long-term locomotor exercise regulates differentially neuronal plasticity-related BDNF and TrkB and NCAM/PSA-NCAM molecules in the lumbar spinal cord in the intact and spinalized rat: implications for spinal cord repair

Czarkowska-Bauch J¹, Macias M¹, Dwornik A¹, Ziemlinska E¹, Nowicka D¹, Skangiel-Kramska J¹, Skup M¹, Fehr S², Schachner M^2
1Department of Neurophysiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland; ²Zentrum für Molekulare Neurobiologie, Universitat Hamburg, Hamburg, Germany
Our research project focuses on a better understanding of the mechanisms underlying the recovery processes following injuries to the spinal cord. An involvement of proteins crucial for the recovery processes, i.e., neurotrophins, their receptors and cell adhesion molecules, which may cause synaptic remodelling of the spinal neuronal network, is our main target. Our preliminary data suggested that the synthesis of both groups of proteins is enhanced in the spinal cord due to physical exercise (Skup, 2002; Macias, 2002). Since locomotor exercise improves stepping ability in animals after spinal cord transection, this prompted us to formulate the hypothesis that an up-regulation of endogenous pools of BDNF and NT-4, their TrkB^FL receptor as well as cell adhesion molecules N-CAM and L1 due to exercise may underlie this effect. A beneficial effect of locomotor training in animals after complete spinal cord transection has often been attributed to the modulation of neurotransmission. Clear links of BDNF and neurotransmitter release prompted us to address also the problem how locomotor exercise influences the segmental distribution of neurotransmitter pools in the spinal cord. Based on these presumptions, we divided our study into two parts: (1) firstly, we aimed to characterize in detail the impact of moderate, long-term locomotor exercise (28 days) on various populations of neurons and non-neuronal cells in the intact lumbar spinal cord of the rat by evaluating gene and protein expression of these molecules. (2) secondly, we characterized the impact of complete spinal cord transection on these molecules and the effect of training on them. Immunohistochemical (IR) as well as in situ hybridisation techniques were employed, supported by the Image ProPlus Analysis...


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