Effects of Fluoxetine and Visual Experience on Glutamatergic and GABAergic Synaptic Proteins in Adult Rat Visual Cortex

Presynaptic vesicle cycling and transporter proteins. In contralateral V1, synapsin (A) was not affected by experimental condition. For synaptophysin (B) fluoxetine alone had no effect, MD alone caused a loss of expression, but combining fluoxetine with MD prevented the MD-induced loss. For VGLUT1 (C) fluoxetine alone or with MD caused a loss of expression, but MD alone increased expression. VGAT (D) was not affected by experimental condition. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.

Postsynaptic receptor scaffolding proteins and subunits. In contralateral V1, PSD-95 (A) and gephyrin (B) had a similar pattern of changes: fluoxetine alone had no effect, MD alone caused a loss of expression, but combining fluoxetine with MD prevented the MD-induced loss and caused super-compensation above normal levels. GluN1 (C) was reduced by fluoxetine regardless of visual experience, whereas MD alone caused an increase. GluA2 (D) was unaffected by fluoxetine alone, MD caused an increase, but combing fluoxetine with MD caused a decrease. GluN2B (E) was reduced by fluoxetine regardless of visual experience, whereas MD had no effect. GluN2A (F) expression of each experimental group was not different from normal animals, but the MDed group had higher expression than either fluoxetine alone or fluoxetine combined with MD. GABAAα3 (G) was unaffected by fluoxetine alone, MD caused an increase, but combing fluoxetine with MD prevented the MD-induced increase. GABAAα1 (H) was increased by fluoxetine regardless of visual experience, while MD alone had no effect. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.

Postsynaptic receptor subunit balances. Neither fluoxetine, MD, nor fluoxetine combined with MD affected the relative abundance of GluN1-containing NMDARs and GluA2-containing AMPARs in contralateral V1 (A). Fluoxetine shifted the relative abundance of NMDAR subunits in favor of the more mature GluN2A subunit, regardless of visual experience. MD caused a shift in favor of the more immature GluN2B (B). Fluoxetine shifted the relative abundance of GABAAR subunits in favor of the more mature α1 subunit, regardless of visual experience. MD caused a shift in favor of the more α3 subunit (C). *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.