RT Journal Article SR Electronic T1 Degeneration of the Amygdala/Piriform Cortex and Enhanced Fear/Anxiety Behaviors in Sodium Pump α2 Subunit (Atp1a2)-Deficient Mice JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 4667 OP 4676 DO 10.1523/JNEUROSCI.23-11-04667.2003 VO 23 IS 11 A1 Keiko Ikeda A1 Tatsushi Onaka A1 Makoto Yamakado A1 Junichi Nakai A1 Tomo-o Ishikawa A1 Makoto M. Taketo A1 Kiyoshi Kawakami YR 2003 UL http://www.jneurosci.org/content/23/11/4667.abstract AB The sodium pump is the enzyme responsible for the maintenance of Na+ and K+ gradients across the cell membrane. Four isoforms of the catalyticα subunit have been identified, but their individual roles remain essentially unknown. To investigate the necessary functions of the α2 subunit in vivo, we generated and analyzed mice defective in the α2 subunit gene. Mice homozygous for the α2 mutation died just after birth and displayed selective neuronal apoptosis in the amygdala and piriform cortex. In these regions, high expression of c-Fos before apoptosis indicated neural hyperactivity, and re-uptake of glutamic acid and GABA into P2 fraction containing crude synaptosome was impaired. These results indicate that the α2 subunit plays a critical role regulating neural activity in the developing amygdala and piriform cortex. Further supporting a role of theα2 subunit in the function of the amygdala, heterozygous adult mice showed augmented fear/anxiety behaviors and enhanced neuronal activity in the amygdala and piriform cortex after conditioned fear stimuli.