The electrophysiological consequences of MeCP2 dysfunction have also been examined. Reduced long-term potentiation (LTP) and long-term depression (LTD) have been reported in hippocampal CA1 synapses in both Mecp2tm1.1Bird and Mecp2tm1.1Jae mice (Asaka et al., 2006), as well as Mecp2tm1Hzo mice (Moretti et al., 2006). Recordings from sensory and motor cortex from Mecp2tm1Hzo mice also revealed reduced LTP (Moretti et al., 2006). Whole-cell patch-clamp recordings from pyramidal neurons in brain slices of somatosensory cortex from Mecp2tm1.1Jae mice revealed reduced spontaneous activity due to a significant reduction in the amplitude of miniature excitatory postsynaptic currents (mEPSCs) and an insignificant increase in the amplitude of miniature inhibitory postsynaptic currents (mIPSCs; Dani et al., 2005). Similarly decreased frequency of mEPSCs and amplitude of evoked EPSCs have also been observed in cultured neurons from Mecp2tm1.1Bird mice and are associated with decreased numbers of glutamatergic synapses on individual neurons (Chao et al., 2007).
