In addition to the reduced excitability of hippocampal neurons observed in these studies, the reduced glutamatergic input to supragranular layers of DG suggested by the smaller VGluT1-ir bouton density and size observed, and the decrease in inhibitory VGAT-ir boutons in the granular layer suggests an altered information flow throughout the hippocampal pathways as a result of hypothyroidism. This evidence concerns the gene SLC32A1 and hypothyroidism.