Figure 2

Developmental change in glutamatergic response at the proximal site. (A) Schematic diagram of experimental procedures. Three domains of dendritic regions of axonless GCs are divided (distal dendrite = red, proximal dendrites = pink, basal dendrites = blue). Whole-cell recordings (gray, Rec) were performed from soma of GFP-positive GCs (green) and the stimulating electrode (gray, Stim) activated centrifugal fibers (black). (B) Typical plot of response amplitude by minimal stimulation. Membrane potential is shown below and drug application above the plot. (C) Representative average traces. 3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated excitatory postsynaptic currents (EPSCs) (blue) were recorded at the holding potential of -70 mV in the presence of 10 μmol/l SR-95531 (gabazine). N-methyl D-aspartate (NMDAR)-mediated EPSCs (red) were recorded at +40 mV in the presence of a combination of 10 μmol/l SR-95531 and 10 μmol/l 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide (NBQX). Scale bar = 50 ms and 2.5 pA. (D) NMDAR-mediated EPSCs gradually increased during maturation (class 3 versus class 5; *P < 0.05) (class 3: six slices, six mice; class 4: nine slices, eight mice; class 5: four slices, four mice). (E) The amplitude of AMPAR-mediated EPSCs was much higher in class 5 than in class 4 cells (class 3 versus class 4, class 3 versus class 5; *P < 0.05) (class 3: twelve slices, eleven mice; class 4: sixteen slices, fourteen mice; class 5: eleven slices, eight mice).