Homeostatic plasticity in the visual thalamus by monocular deprivation.

Monocular deprivation (MD) is a classic paradigm for experience-dependent cortical plasticity. One form is known as homeostatic plasticity, in which neurons innervated by the deprived eye show a remarkable capacity to compensate for degraded visual signals in an attempt to stabilize network activity. Although the evidence supporting homeostatic plasticity in visual cortex is extensive, it remains unclear whether neurons in subcortical visual structures respond to MD in a similar manner. Here we examined whether cells in the dorsal lateral geniculate nucleus (dLGN), the thalamic relay between the retina and visual cortex, show similar forms of experience-dependent homeostatic plasticity following MD. Two-week-old mice were monocularly deprived for a period of 5-7 d and miniature EPSCs (mEPSCs) were obtained from cells located in dLGN regions receiving input from the deprived or nondeprived eye. We found that MD promotes increases in the frequency and amplitude of mEPSCs and were restricted to the monocular segment contralateral to the deprived eye. These changes were accompanied by an increase in the probability of glutamate release at corticothalamic terminals that arise from the deprived visual cortex. Our findings indicate that homeostatic synaptic regulation from MD extends beyond cortical circuitry and shed light on how the brain modulates and integrates activity in the face of altered sensory experience.