The effect of 5 and 10 s laser illumination on normalized prepulse ICa (A), holding current (B), l-Glu (100 μm)-induced prepulse ICa inhibition (C) and facilitation ratio (D), in the absence (open bars) or presence (filled bars) of FL–BTX labelling in BBS–mGluR8a-expressing neurons. The grey bar indicates the presence of the singlet oxygen quencher NaN3 (10 mm) in the extracellular and intracellular solutions. The measurement of the holding current, the prepulse ICa, normalized agonist-induced inhibition and facilitation ratio were as described in Fig. 3. *P < 0.05, **P < 0.01, ***P < 0.001 compared with the control groups.