Fig. 4.

dl-Threo-β-benzyloxyaspartate (TBOA) and gabazine (Gbz)/strychnine (Stry) increase wave frequency as detected by FLII⁸¹E-1μ and two-photon Ca²⁺ imaging of neurons in the INL and GCL. A: representative traces of glutamate transients for control (top), Gbz and Stry (middle) and TBOA (bottom). B: raster plots of neuronal Ca²⁺ transients detected by two-photon Ca²⁺ imaging as in Fig. 2C. C: cumulative distributions of interwave intervals for control (black), TBOA (gray), and Gbz/Str (blue) for FRET imaging in the IPL and Ca²⁺ imaging in the INL and GCL. Binning = 10 s. FRET glutamate transients: control, 47 wave intervals, 8 retinas; Gbz/Stry, 135 intervals, 5 retinas; and TBOA, 42 intervals, 5 retinas; Ca²⁺ INL: control, 84 intervals, 16 retinas; Gbz/Stry, 116 intervals, 8 retinas; and TBOA, 127 intervals, 8 retinas; and Ca²⁺ GCL: control, 156 intervals, 15 retinas; Gbz/Stry, 122 waves, 9 retinas; and TBOA, 42 intervals, 6 retinas. D: each image represents the spatial extent and duration of one glutamate transient in control (left), Gbz/Stry (middle left), and TBOA (middle right and right). Gray values correspond to the time during which that region of the retina was active, as in Fig. 1B. Red arrows indicate the propagation direction.