Although astrocytes are now known to be critical in synaptic glutamate reuptake, microglia and oligodendrocytes also function in glutamatergic homeostasis [see recent reviews by Wong et al. (2011) and Bakiri et al. (2009) on microglia and oligodendrocytes, respectively]. Microglial upregulation of the NMDA receptor complex has been observed in MDD but not BD (Steiner et al. 2011). Nevertheless, additional research is critically needed on non-astrocyte-based amino acid neurotransmitter dysfunction in both SUDs and depression to better comprehend convergent pathways and offer novel treatment approaches.
