Does the cerebral cortex exacerbate dopaminergic cell death in the substantia nigra of 6OHDA-lesioned rats?

We have explored the survival of dopaminergic cells of the substantia nigra pars compacta (SNc) in 6 hydroxydopamine (6OHDA)-lesioned rats with prior cortical removal. There were approximately 35% more dopaminergic cells in the ventral sector of SNc (vSNc) of 6OHDA-lesioned rats that had prior cortical removal compared to those that did not. By contrast, there were no differences in dopaminergic cell number between these experimental groups in the ventral tegmental area (VTA) and the dorsal sector of SNc (dSNc). Hence, prior cortical removal in 6OHDA-lesioned rats neuroprotected vSNc--but not VTA or dSNc--dopaminergic cells from death.