A mouse model of Tuberous Sclerosis Tsc2+/– exhibits reduced mGluR-LTD (LTD) in the hippocampus and altered levels of mGluR signaling Arc (activity-regulated cytoskeleton-associated) protein, which is crucial for AMPAR internalization in cerebellar LTD (Auerbach et al., 2011). The gene discussed is TSC2; the disease is tuberous sclerosis.