Fig. 4. Adult male mice early postnatally lacking FGFR driven by GFAP- CreER^T2 (induced with neonatal tamoxifen injections P1-7) show reduced astrocyte processes in neuropil by electron microscopy.

A–D Less glial coverage of perikaryal membrane (black lines) and more synapse number on the same membrane (asterisks) in FGFR2 nKO compared to control littermate mice in the hippocampus CA3 region (30 cells per genotype). N = 3,3. These mice also show increased density of pre-synaptic proteins assessed by immunofluorescence. E–H Greater number of puncta of vGLUT1 and vGAT per field of analysis in lateral cortex. I, J Greater number of vGAT puncta in cortical layers I-III when evaluated separately from cortical layers IV-VI. N = 4,4; *p < 0.05, **p < 0.01 two-tailed Student’s t-tests or ANOVA. Means and SEM shown.