Table 1.

Quantitation of CX3CL1 in brain and serum of healthy mice

Tissue/genotype	Cx3cr1+/+	Cx3cr1−/−	Fold change
Brain
Protein, pg*	1500 ± 800	48000 ± 300†	> 30
mRNA, fg	44 ± 10	43 ± 10	1
Blood, protein, pg*	780 ± 200	191000 ± 80000‡	> 300

Soluble CX3CL1 was measured by ELISA in brain aqueous homogenates (n = 4 mice per group) and serum (n = 9 mice per group).

^*Data represent the mean plus or minus standard deviation (SD) in pg/mg protein. Brain and circulating levels were significantly higher in Cx3cr1^−/− mice compared with wild-type mice.

^†P < .001,

^‡P = .003. CX3CL1 message was quantified by real time RT-PCR, showing no statistical significance in brain mRNA expression; n = 4 mice per group.