Disparate effects of BPS treatment were also observed in the averaged mitochondrial mass, i.e., the volume of mitochondria per cell. Contrarily to the IC, the PD+/LRRK2+ neurons significantly increased their mitochondrial mass (Figure ), suggesting that the PD cells accumulate mitochondria due to an impaired mitochondrial clearance mechanism, as previously reported for PD+/LRRK2+ murine models . Alternatively, the cells may intensify mitochondrial biogenesis to compensate for the BPS-induced insult. Furthermore, BPS negatively impacted (reduced) the organellar size in the PD+/LRRK2+ neurons (Figure ), a response commonly seen upon mitochondrial stress, and which is necessary for efficient clearance via mitophagy to occur. Interestingly, BPS had the opposite effect in the IC line at 100 µM, with an increased mitochondrial size detected. Finally, the proposed alterations in mitophagy were supported by the assessment of the normalized colocalization of mitochondria and lysosomes, which suggests that IC neurons more efficiently initiate this clearance process ( Figure ), and are therefore able to maintain higher mitochondrial fitness. Further experiments, beyond the scope of this current effort, are ongoing to better understand the impact of BPS exposure on neurons.