Fig. 4.
Altering CPEB expression interferes with tectal cell performance in the visual circuit. (A–C) Whole-cell recordings of visual responses over the complete 2.5 s of the off responses. Each column shows recordings from the same cell for each 10-dB increase in intensity. Twenty responses are superimposed in gray with the average response in black. (D–F) Spontaneous activity recorded during the dark-adaptation period. Gray areas are expanded in the insets. Bursting activity is only seen in control cells. (G) Quantification of average charge transferred (Q) over 500 ms following light off for each stimulus intensity. Compared to control neurons, delCPEB-expressing cells showed significantly lower Q for each intensity tested. CPEB cells were significantly different at the stronger relative intensities. n = 6–10 cells for each intensity for control, CPEB and delCPEB groups. (H and I) Quantification of spontaneous synaptic activity recorded in the absence of TTX. Distribution and means (inset) for the single event amplitudes (H) and inter-event intervals (IEI) (I) were significantly shifted toward smaller values for both delCPEB and CPEB-expressing neurons compared to control cells. n = 1,190 events and 10 neurons per cell group. *, P < 0.05. Values given in Tables S6 and S7.