GRIA4 and glioma: Time-course imaging of individual puncta demonstrated that BDNF exposure elicits an increase in the postsynaptic levels of GluA2 on the glioma cells (Fig. 3k–m), on a time-scale consistent with the increased GluA3 and GluA4 trafficking (Fig. 3b–e) and the change in glutamate-evoked currents (Fig. 2).