In our present study, we evidenced the opposite level of the parvalbumin, pre-synaptic protein MAP2, and postsynaptic excitatory protein PSD-95 expressions locally in the hippocampus, which could be the underlying mechanisms of distinct hippocampal prodromal sleep disorders in the PD cholinopathy vs. the hemiparkinsonism with PD cholinopathy. The gene discussed is PVALB; the disease is sleep disorder.