those observed by Wang et al. and Jaramillo et al. in the hippocampus, but resulted in decreased excitatory synaptic strength, reduced mEPSC frequency, and reduced mEPSC amplitude in MSNs of the dorsolateral striatum (Peça et al., 2011). On the other hand, deletion of exon 21 results in decreased LTP, an increased AMPA/NMDA current ratio, decreased mEPSC frequency, and reduced excitatory synaptic strength in the CA1 region of the hippocampus (Kouser et al., 2013) as well as an increased AMPA/NMDA current ratio in layer 5 prefrontal cortex pyramidal neurons (Duffney et al., 2015). The insertion mutation in exon 21 is similar to deletion of exon 21 in terms of hippocampal electrophysiology, but one difference is that LTD, and not LTP, is impaired (Speed et al., 2015).
