Deprenyl increases survival of rat foetal nigral neurones in culture.

To study the potential of L-deprenyl to rescue dopaminergic neurones from natural death in primary cultures, foetal nigral neurones were prepared from the ventral midbrain of 16 day old rat embryos. L-deprenyl, at final concentrations of 0.1, 1 and 10 microM, or vehicle solution was added to the culture medium. The cells were allowed to survive for 1, 5 and 10 days. They were then fixed and stained for tyrosine hydroxylase (TH) immunohistochemistry, with or without histological staining. After 5 and 10 days, deprenyl at 0.1 microM increases the number of TH-positive profiles in treated cultures when compared with controls but the effect was more evident at 1 and 10 microM. This can be interpreted as increased survival of catecholaminergic neurones. We cannot however rule out the possibility that deprenyl stimulates the expression of TH by other neurones.