(1–3)IGF-1 reverses deficits in LTP and basal synaptic properties in Shank3 -deficient mice. Wild-type (WT) and heterozygous (Het) mice were treated with saline or (1–3)IGF-1 for 2 weeks before testing (injections began at postnatal day (PND) 13 to 15 and animals were analyzed immediately after the last injection). Methods for all experiments were as described previously , with 3 to 4 mice per group, and 1 to 2 slices per animal. (a) Hippocampal LTP was induced with high-frequency stimulation. Inset: Representative excitatory postsynaptic potential traces at 90 min after LTP induction from saline-injected (1) and (1–3)IGF-1-injected (2) heterozygous mice (scale bar: 0.5 mV, 10 ms). (b) Input–output curves comparing field excitatory postsynaptic potential (EPSP) slopes (mV/ms) as a function of stimulation intensity (mA). EPSP: excitatory postsynaptic potential; Het: heterozygous; LTP: long-term potentiation; PND: postnatal day; WT: wild-type.