GDNF and glioblastoma: In addition, antidepressant exposure increased GDNF release in a rat C6 glioblastoma cell line (Hisaoka et al. 2001), whereas lithium treatment in rats resulted in increased GDNF concentrations in the PFC and occipital cortex but a decrease in the hippocampus (Angelucci et al. 2003b).