Nevertheless, insulin promotes synaptic plasticity by increasing synaptic markers (synapsin 1, synaptophysin, and PSD95) in the olfactory bulb And prefrontal cortex from 3xTg-AD mice [249], and enhances insulin responsiveness and LTD in hippocampal slices from Tau22 transgenic mice [250]. The gene discussed is SYN1; the disease is Alzheimer disease.