Table 3.

Studies examining alterations in the expression levels of neurotransmission-related genes.

Citation	Sample	Methods	Gene	Main findings	Tissue
Kunii et al. 201571	176 schizophrenic patients 61 BPD patients 138 MDD patients 326 healthy controls	RT-qPCR	CHRFAM7A, CHRNA7	Increased expression levels of CHRNA7 mRNA in MDD patients compared with all other groups. Expression of CHRFAM7A was significantly elevated in all diagnostic groups compared with the control group.	Postmortem brain tissues
Gray et al. 201580	53 MMD patients: 26 males and 27 females 34 MDD suicide and 19 MDD non-suicide 32 healthy controls: 19 males and 13 females	RT-qPCR	GluR genes	The majority of the 21 GluR genes that were tested showed higher levels of expression in the MDD subjects relative to controls. The greatest effects were detected in the female groups.	Postmortem brain tissues
Chandley et al. 201386	19 MDD patients 20 healthy control	RT-qPCR immunostaining	SLC1A3, SLC1A2, GLUL, GFAP	Astrocytes, but not oligodendrocytes, demonstrated robust reductions in the expression of SLC1A3 and SLC1A2, whereas GLUL expression was unchanged in MDD patients when compared with controls. GFAP expression was lower in astrocytes, and we confirmed reduced GFAP protein in the LC using immunostaining methods.	Postmortem brain tissues
Chandley et al. 201481	18 MDD patients 18 healthy controls	RT-qPCR	GRIN1, GRIN2A, GRIN2B, GRIN2C, GRIN2D, GRIN3A, GRIN3B, GRIA1, GRIA2, GRIA4, GRIK1, GRIK3, GRIK5, GRM4, GRM5, GRM8	MDD subjects exhibited significantly higher expression levels of the NMDA receptor subunit genes, GRIN2B and GRIN2C and the metabotropic receptor genes, GRM4 and GRM5, in LC neurons.	Postmortem brain tissues
Oh et al. 201488	15 MDD patients: 7 with suicide, 8 without suicide 15 healthy controls	Reanalysis of existing postmortem data, found in the Stanley neuropathology consortium integrative database, a web-based tool that integrates datasets from the same postmortem brain samples.	GAD1, SLC1A1, SLC1A2, SLC1A3	The mean GAD1 mRNA was almost all slightly lower in the subjects with MDD as compared with the control group. While SLC1A1-3 mRNA expression was generally lower in the subjects with MDD as compared to the controls in each sub-region, it was only in the white matter (BA46) that SLC1A2 mRNA was significantly lower in the subjects with MDD as compared to the normal control group.	Postmortem brain tissues

MDD major depressive disorder, PCR polymerase chain reaction, RT-qPCR reverse transcription (RT) quantitative PCR, BPD bipolar disorder.