Fig. 5.

Electron micrographs showing developing PF→PC synapses in the GluRδ2 mutant (A, C) and wild-type (B, D) mice. A, B, P7. Note small synaptic contacts (arrowheads), which are not fully surrounded by astroglial investments in both mice. C,D, P14. PF→PC synapses (arrowheads) develop normal structure in both mice. However, profiles of unattached PC spines (asterisks) are more obvious in the mutant mouse. Note that unattached spines often possess a small PSD-like condensation in the mutant mouse but not in the wild-type mouse. Scale bar, 0.5 μm.