In our preliminary investigations, Golgi staining and immunohistochemical analyses revealed that diabetes significantly reduced dendritic spine density in hippocampal neurons (Fig. S2A), accompanied by aberrant increases in GABAergic neurotransmission and decreased expression of the excitatory neuronal marker c-Fos (Fig. S2B-C)(Schell et al. 2012; Srivastava et al. 2020). The gene discussed is FOS; the disease is diabetes mellitus.