Figure 4. Higher probability of neuronal firing during Up states in Fmr1–/– mice.
(a) Sample traces during Up/Down states from in vivo whole cell recordings of L2/3 neurons in unanesthetized WT (top) and Fmr1–/– mice (bottom). The highlighted segments are expanded in panel b.
(b) Expanded traces of Up & Down segments in WT (top) and Fmr1–/– mice (bottom).
(c, d) Mean duration (c) and frequency (d) of Up states in WT and Fmr1–/– mice. Note that not all recordings (or neurons) showed segments that were classified as Up/Down states (n = 5 and 6 recording segments with Up/Down states in WT and Fmr1–/– mice, respectively). There were no significant differences between genotypes.
(e) Mean Up-Down voltage step (in mV) in WT and Fmr1–/– mice. The trend toward higher step in mutant mice was not significant (p = 0.21, t-test).
(f) Mean number of action potentials per active Up state (i.e., Up states with 1 or more spikes) in WT and Fmr1–/– mice. p = 0.07, t-test.
(g) Mean firing probability during any given Up state (active or silent) in WT and Fmr1–/– mice. **p < 0.01, t-test.
