Gene expression profiles of normal and activity-silenced mitral cells at P3 and P6

Mitral cells in the mouse olfactory bulb are known to remodel their primary dendrites and form lateral dendrites during postnatal development. These processes are suppressed when neuronal activity is silenced by overexpression of Kir2.1 in mitral cells, indicating that neuronal activity in mitral cells is required. However, it is unclear what changes in gene expression lead to the remodeling of mitral cell dendrites in an activity-dependent manner. To address this, we performed a microarray-based analysis of gene expression in mitral cells during normal development and under the activity-silenced condition. We analyzed four groups: EYFP+ mitral cells at P3, EYFP+ mitral cells at P6, Kir2.1-expressing EYFP+ mitral cells at P3, and Kir2.1-expressing EYFP+ mitral cells at P6. We used 40 mitral cells for each group. After cDNA synthesis from single cells, the 40 cDNA samples were divided into 4 biological replicates, each of which contains cDNA from 10 mitral cells.