Figure 3.

Matching of neurotransmitters and receptors at NMJs in vivo. Whole-cell recordings from muscle cells of the axial musculature of 3 day (stage 40) (a) control, (b) Ca²⁺ spike-suppressed and (c) Ca²⁺ spike-enhanced larvae were performed in the presence of 2 mM Ca²⁺, Mg²⁺-free saline and 3 μM TTX; V_h=−80 mV. Examples illustrate the pharmacological blockade of the miniature postsynaptic currents (mpscs) from two muscle cells in each group of embryos. Single mpscs are shown on an expanded time base to illustrate their kinetics. (d) Incidence of cholinergic, glutamatergic, GABAergic and glycinergic NMJs. Bars represent the percentage of each class of NMJ in each group based on blockade by different receptor antagonists (blue, nAChR; red, AMPAR; light orange, NMDAR; yellow, NMDAR+nAChR; lavender, GABA_AR+nAChR; light turquoise, GlyR+nAChR). Values are from 6 control, 12 spike-suppressed and 13 spike-enhanced NMJs. CNQX, 6-cyano-7-nitroquinoxaline-2,3-dione. Reproduced with permission from Borodinsky & Spitzer (2007).