Figure 3. AAV-CREB results in higher CREB mRNA levels in CA1, and reduces AHP in infected aged animals.

CREB mRNA levels relative to young GFP group in a) CA1, (b) DG, and c) CA3. In both young and aged animals, AAV-CREB injected animals had more CREB mRNA in CA1 (n = 7, 7, 17, 15). This viral difference was not observed in DG (n = 4, 6, 4, 6) or CA3 (n = 4, 6, 4, 6). (d) Peak postburst AHP is significantly reduced in CA1 pyramidal neurons (n = 7) from aged AAV-CREB animals as compared to control cells (n = 23) from aged animals. No significant differences were observed in peak postburst AHP between CA1 neurons from young adult (n = 39) and aged AAV-CREB animals. (e) Similarly, the slow postburst AHP from CA1 neurons of young adult and aged AAV-CREB animals were significantly reduced as compared to control cells from aged animals. (f) Example postburst AHP traces from aged CREB+ (green) and aged control (black) CA1 pyramidal neurons. Arrow indicates 1 s time point where slow postburst AHP was measured. Results in a, b, c represent mean ± SEM.

DOI: http://dx.doi.org/10.7554/eLife.19358.005

Figure 3—figure supplement 1. Aged unimpaired and impaired animals had the same amount of CREB mRNA.

Upon separating the aged GFP group into AU and AI, CREB mRNA levels were not different between AU and AI animals. Horizontal bars represent mean.

DOI: http://dx.doi.org/10.7554/eLife.19358.006

Figure 3—figure supplement 2. CREB protein levels are positively correlated with probe trial performance in aged GFP animals.

Levels of CREB protein in CA1 of aged GFP animals are correlated with % time spent in target quadrant on a probe trial run 1 hr after the last training session. Aged rats with more basal levels of CREB protein performed better on the probe trial.

DOI: http://dx.doi.org/10.7554/eLife.19358.007

Figure 3—figure supplement 3. Viral infection state had no effect on postburst AHP size in young CA1 pyramidal neurons, but did affect aged neurons.

(a) Peak and b) slow AHP were measured in AAV-CREB infected cells (CREB+), AAV-CREB uninfected cells (CREB−), and cells from AAV-GFP injected young animals (n = 9, 17, 13). For both measurements, no differences were observed between the three groups. (c) Peak and d) slow AHP were measured in AAV-CREB infected cells (CREB+), AAV-CREB uninfected cells (CREB-), and cells from AAV-GFP injected aged animals (n = 7, 9, 14). For both measurements, while CREB+ cells had significantly smaller amplitudes when comparing to both CREB- and GFP cells, the CREB- and GFP cells were not different from each other. Horizontal bars represent mean.

DOI: http://dx.doi.org/10.7554/eLife.19358.008