Table 2. RA concentrations in whole brain and brain loci.

Quantification was carried out with brains from 12-month-old female C57BL/6 mice fed with a stock diet. Values are the means±S.E.M. (the number of mice assayed is given in parentheses) expressed in pmol/g of tissue.

Sample	atRA	13-cis-RA
Brain (whole)	5.4±0.4 (4)*	1.5±0.4 (5)
Cerebellum	10.7±0.3 (4)*	3.0±0.8 (4)
Cortex	2.6±0.4 (8)*	1.8±0.3 (8)
Hippocampus	8.4±1.2 (8)	7.8±0.8 (8)
Striatum	15.3±4.7 (5)	8.0±2.2 (5)

* Statistically different from each other (P<0.001).