Fig. 2.

Reduced basal interaction of mGlu5 with the long isoform of Homer due to loss of GluD1. (A) GluD1 KO does not exhibit a detectable change in mGlu5 expression in total protein fraction from the CA1 region (N = 5). (B) Degree of interaction between mGlu5 and Homer was assessed in wild-type (WT) and GluD1 KO under basal conditions and in response to DHPG. Horizontal hippocampal sections were either sham treated with aCSF or treated with DHPG (100 µM, 5 minutes) followed by collection of total protein after 60 minutes. Immunoprecipitation was performed for Homer (long isoform) followed by immunoblotting for mGlu5 and Homer. Under basal conditions, the ratio of mGlu5/Homer was lower in GluD1 KO (*P < 0.05, unpaired t test). Treatment with DHPG reduced the interaction between mGlu5 and Homer in wild-type CA1 (#P < 0.05) but produced an increase in interaction in GluD1 KO ($$P < 0.01). Amount of mGlu5 and Homer in the total lysate used for immunoprecipitation was unaltered between wild-type and GluD1 KO or by treatment. N = 3 mice/genotype. The optical density was normalized to control value for individual experiments. Additionally, the individual control values were normalized to average of control. IB, immunoblot.