The fact that ERK activation was also observed after LTP stimulation in hippocampal slices from adult rats with hypothyroidism induced in the pre- and postnatal periods, as well as in the hippocampus of newborn rat pups born to hypothyroid dams, suggests that disturbances in synaptic plasticity associated with a deficiency of thyroid hormones result from changes in ERK signaling [11,32]. The gene discussed is MAPK1; the disease is hypothyroidism.