Figure 4.

Reproducible glutamate responses are inhibited by glutamate antagonists. (a, c + e) Representative Ca²⁺ imaging traces of neuronal responses to repeated glutamate applications in the absence or presence of antagonists or TTX (purple trace: individual neuronal responses; red trace: average response). NFU = Normalised fluorescent unit. (b) Repeated applications of glutamate (3 μM) revealed a small but significant reduction in neuronal response during the third glutamate application. (d) The neuronal response to glutamate (3 μM) application was reversibly inhibited in the presence of glutamatergic antagonists (NBQX 20 μM, DL-AP5 100 μM & (R,S)-MCPG 500 μM). (f) The neuronal response to glutamate (3 μM) application was not significantly affected in the presence of TTX (1 μM). Data are presented as mean ± S.E.M. with one-way ANOVA with post-hoc Tukey’s test performed; n ≥ 189 neurons per application, from ≥3 devices from ≥3 separate cultures; ^*denotes P < 0.05 and ^***denotes P < 0.001.