Figure 3. PPC stimulation in aged mice restores exploration and learning.
a. Chrmine, the red-shifted excitatory opsin, was virally expressed and fiber optic cannulas were implanted in PPC bilaterally. The brain slice on the left demonstrates a successful expression of Chrmine in PPC.
b. In optogenetic sessions (first 16 training sessions), on randomly selected trials (~23%), LED light was turned on during the inter-trial interval.
c. The degree of perseverance, exploitation, and exploration in G1, G4, and G4-opto groups. G1 and G4 are the same as in Figures 1 and 2. G4-opto matches G4 in age, but PPC was stimulated. Dots: individual mice.
d. The comparison of exploit and exploration across the trial subgroups in G4: all trials from the control group, all trials from the optogenetic group, LED-off trials from the optogenetic groups, and LED-on trials from the optogenetic group.
e. The learning curves. Mean ± S.E.
f. The fraction of learned mice within 30 training days.
g. The learning rate.