Figure 4

Increased mGluR5 cell surface expression does not alter InsP signaling in 12 month old APPswe/PS1ΔE9 mice . (A) Shown is a representative immunoblot showing increased cell surface expression, but not total cellular expression, of mGluR5 in brain lysates derived from 12 month wild-type (wt) versus APPswe/PS1ΔE9 (APPswe) mice. Loss of mGluR5 expression following mGluR5 knockout is also shown for both mouse lines. (B) Graph shows the quantification of the relative cell surface expression of mGluR5 in wt versus APPswe mice at 12 months of age. Data represents the mean ± SEM of four independent experiments. The * indicates statistically significant (P < 0.05) differences between in APPswe mice, as compared to wt mice (P < 0.05). Shown in (C) is mGluR1/5-stimulated InsP formation in response to either 5 μM or 50 μM DHPG for 15 min at 37°C in cortical prisms derived from either wt or APPswe mice, that either express mGluR5 (+/+) or do not express mGluR5 (-/-). The data represents the means ± SEM of four independent experiments, and is expressed as percentage of the maximum response to 50 μM DHPG-stimulated InsP formation in wild type slices. The * indicates statistically significant (P < 0.05) differences in InsP formation following treatment of tissue with either 5 or 50 μm DHPG concentrations between cortical prisms derived from wt and APPswe mice and cortical prisms derived from wt and APPswe/PS1ΔE9 mice that do not express mGluR5. ^# Indicates statistically significant (P < 0.05) differences in InsP formation following treatment of tissue with either 5 and 50 μm DHPG concentrations between cortical prisms derived from wt and APPswe that do not express mGluR5.