Table 1.

Fgf2 −/− mutant mice show a significant decrease in the pyramidal neurons of the cortex, whereas the interneurons are unchanged

	Cell number (millions ± SEM)
	Glutamate	GABA	Calbindin	Parvalbumin
Wild-type	6.478  ± 0.624	2.473  ± 0.755	1.69  ± 0.306	1.035  ± 0.108
Fgf2−/−	4.017  ± 0.399	2.533  ± 0.251	1.765  ± 0.165	0.995  ± 0.044
% Wild type	62%	102%	104%	96%

Fgf2 null mutant mice (Fgf2 −/−) show a significant decrease in number of glutamate-positive pyramidal neurons in the cerebral cortex, whereas the number of GABA-, calbindin-, and parvalbumin-containing interneurons remain unchanged. Cell numbers in the neocortex were estimated by stereologial analysis using the optical dissector method. No statistically significant differences in cortical volume were observed between genotypes. ANOVA showed that the decrease in glutamate-containing cells was statistically significant (genotype main effect, F = 9.95; p < 0.001).n = 6 mice per genotype: three on C57BL/6 and three on 129Sv:black Swiss background. The glutamate/GABA ratio is approximately 3:1 in wild-type mice and 2:1 in Fgf2 knock-outs.