DLG4 and depressive symptom measurement: To test whether synapse loss occurs in the hippocampal CA1 region in reserpine-induced depression in a Parkinson’s disease mouse model, we measured the synaptic density of colocalized puncta of VGlut2 and PSD95 at excitatory synapses and colocalized puncta of VGAT and Gephyrin at inhibitory synapses (Fig. 6a, b).