Gene expression analysis of mouse brain.

Inbred mouse strains differ in their innate anxiety levels. We used RNA-sequencing to identify gene expression differences in hippocampus and frontal cortex of six mouse strains. Mice were singly housed for one week before dissections and killed by cervical dislocation between 8 a.m. and 11 a.m. Dissections were performed on a Petri dish filled with ice. FCx included 2 mm of the anterior part of the cortex. The Hpc was dissected whole. Samples were directly frozen in liquid nitrogen and stored in -80°C. We extracted total RNA with TriReagent according to the manufacturer's instructions and verified its quality by the Agilent Bioanalyzer Small RNA Analysis and RNA 6000 Nano Kits. Ribo-depleted RNA was sequenced with Illumina High-Seq 2000.