A gene-cell construct based on rat olfactory mucosa ensheathing cells transduced with an adenoviral vector encoding a mature form of brain neurotrophic factor (mBDNF) was transplanted into post-traumatic cysts of rat spinal cord. Transplantation of the gene-cell construct improved motor activity of the hind limbs and reduced the size of cysts in some animals. However, comparison of the effects of transduced and non-transduced ensheathing cells revealed no significant differences. In parallel in vitro experiments, a decrease in the proliferation of transduced cells compared to non-transduced cells was observed. It is likely that mBDNF reduces proliferation of transduced cells, which can affect their efficiency. The therapeutic efficacy of the new gene-cell construct is most likely provided by the cellular component.