Fig. 6. Aged SynII^–/– but not SynI^–/–, mice display increased astrogliosis in the CA1 region of the hippocampus. (A) Immunostaining with anti-GFAP antibodies of 10-µm cryostat sections of the CA1 hippocampal field of aged WT, SynI^–/– and SynII^–/– brains (9-12 mice per group). Scale bar: 50 µm. (B) Schematic drawing of a coronal section of mouse brain at bregma level –1.55 mm (modifed from the Allen Reference Atlas, http://www.brain-map.org/welcome.do), showing the sampled region of the hippocampal field CA1 (boxed area). (C) The GFAP immunopositive field area was measured and is expressed as a percentage of the total sampled area. The data, plotted as means ± s.e.m., showed a selective increase in the GFAP-immunoreactive area (+24.5±5%) in SynII^–/– mice with respect to age-matched WT or SynI^–/– mice. Statistical analysis was performed by means of one-way ANOVA [F(2,31) = 9.65, P<0.001] followed by Bonferroni's multiple comparison test (^***P<0.001 SynII^–/– vs WT mice; °P<0.05 SynII^–/– vs SynI^–/– mice).