Delayed onset of striatal projection neuron hyperexcitability in Fmr1−/y mice

These findings reveal that DMS SPN hyperexcitability in <i>Fmr1-/y</i> mice emerges after early postnatal development, pointing to a progressive trajectory of striatal abnormalities. In addition, these results underscore the importance of developmental timing in FXS pathophysiology and emphasize the need for targeted interventions to address SPN dysfunction.