When normal binocular visual experience is disrupted during postnatal
development, it affects the maturation of cortical circuits and often
results in the development of poor visual acuity known as amblyopia.
Two main factors contribute to the development of amblyopia: visual
deprivation and reduced binocular competition. We investigated the
affect of these two amblyogenic factors on the expression of the NMDAR1
subunit in the visual cortex because activation of the NMDA receptor is
a key mechanism of developmental neural plasticity. We found that
disruption of binocular correlations by monocular deprivation promoted
a topographic loss of NMDAR1 expression within the cortical
representations of the central visual field and the vertical and
horizontal meridians. In contrast, binocular deprivation, which
primarily affects visual deprivation, promoted an increase in NMDAR1
expression throughout the visual cortex. These different changes in
NMDAR1 expression can be described as topographic and homeostatic
plasticity of NMDA expression, respectively. In addition, the changes
in NMDA expression in the visual cortex provide a greater understanding
of the neural mechanisms that underlie the development of amblyopia and
the potential for visual recovery.