KA‐bridged transplantation of mesencephalic tissue and olfactory ensheathing cells in a Parkinsonian rat model

The pathology of Parkinson's disease (PD) results mainly from nigrostriatal pathway damage. Unfortunately, commonly used PD therapies do not repair the disconnected circuitry. It has been reported that using kainic acid (KA, an excitatory amino acid) in bridging transplantation may be useful to generate an artificial tract and reconstruct the nigrostriatal pathway in 6‐hydroxydopamine (6‐OHDA) lesioned rats. In this study, we used KA bridging and a co‐graft of rat olfactory ensheathing cells (OECs) and rat E14 embryonic ventral mesencephalic (VM) tissue to restore the nigrostriatal pathway of the PD model rats. The methamphetamine‐induced rotational behaviour, 4‐[18F]–ADAM (a selectively serotonin transporter radioligand)/micro‐PET imaging, and immunohistochemistry were used to assess the effects of the transplantation. At 9 weeks post‐grafting in PD model rats, the results showed that the PD rats undergoing VM tissue and OECs co‐grafts (VM–OECs) exhibited better motor recovery compared to the rats receiving VM tissue transplantation only. The striatal uptake of 4‐[18F]–ADAM and tyrosine hydroxylase immunoreactivity (TH‐ir) of the grafted area in the VM–OECs group were also more improved than those of the VM alone group. These results suggested that OECs may enhance the survival of the grafted VM tissue and facilitate the recovery of motor function after VM transplantation. Moreover, OECs possibly promote the elongation of dopaminergic and serotonergic axon in the bridging graft. Copyright © 2015 John Wiley & Sons, Ltd.