Table 3.

Summary of mRNA expression levels of genes encoding subunits of the mitochondrial complexes and energy metabolism‐related enzymes in the frontal cortex in MA, iPD, PD and PDD. Up‐regulated gene expression occurs in PD 5–6 when compared with MA and PD 3–4. However, important decay in gene expression is observed in PDD when compared with PD. Student's T‐test *P < 0.05, **P < 0.01, ***P < 0.001. ^†No Gaussian distribution (Mann–Whitney test *P < 0.05, **P < 0.01, ***P < 0.001.

		Frontal cortex
		MA vs. PD 3–4	MA vs. PD 5–6	PD 3–4 vs. PD 5–6	MA vs. PDD	PD 3–4 vs. PDD	PD 5–6 vs. PDD
Mitochondrial elements
Complex I	NDUFA2	–	–	↑*	–	–	–
	NDUFA7	–	↑**	↑**	–	–	↓**
	NDUFA10	–	↑**	↑*	–	–	↓*
	NDUFB3	↓*	–	↑**	–	–	–
	NDUFB7	–	↑*	–	–	–	↓*
	NDUFB10	–	↑*	–	–	–	↓*
	NDUFS8	–	↑*	–	–	–	↓*
Complex II	SDHB	–	↑*	–	↓*	–	↓*
Complex III	UQCRB	–	–	–	–	–	↓*
	UQCR11	–	↑*	–	–	–	–
Complex IV	COX7A2L	–	↑*	–	–	–	↓**
	COX7C	–	–	–	↓*	–	↓*
Complex V	ATP5G2	–	↑*	↑*	↓*	–	↓**
	ATP5H	↓**	–	↑**	–	–	–
	ATP5L	–	–	↑*	–	–	↓**
	ATP5O	–	–	–	–	–	↓*
Energy metabolism‐related molecules
	ATP2B4	↓*	–	↑**	↓*	–	↓*
	ATP4A	↑*	–	↑**	–	–	–
	ATP6V0A1	–	–	↑**	–	–	↓*
	ATP6V0B	↓**	–	↑**	↓**	–	↓*
	ATP6V1H	–	–	–	–	–	↓**
	FAM82A2	–	–	–	↓*	–	–
	LHPP	–	–	–	↓*	–	–
	TOMM40	↓*	–	↑*	–	–	–
	ZNF642	–	↑**	↑***	–	–	↓**