RT Journal Article SR Electronic T1 Acid-Sensing Ion Channel 1 Is Localized in Brain Regions with High Synaptic Density and Contributes to Fear Conditioning JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 5496 OP 5502 DO 10.1523/JNEUROSCI.23-13-05496.2003 VO 23 IS 13 A1 Wemmie, John A. A1 Askwith, Candice C. A1 Lamani, Ejvis A1 Cassell, Martin D. A1 Freeman, John H. A1 Welsh, Michael J. YR 2003 UL http://www.jneurosci.org/content/23/13/5496.abstract AB The acid-sensing ion channel, ASIC1, contributes to synaptic plasticity in the hippocampus and to hippocampus-dependent spatial memory. To explore the role of ASIC1 in brain, we examined the distribution of ASIC1 protein. Surprisingly, although ASIC1 was present in the hippocampal circuit, it was much more abundant in several areas outside the hippocampus. ASIC1 was enriched in areas with strong excitatory synaptic input such as the glomerulus of the olfactory bulb, whisker barrel cortex, cingulate cortex, striatum, nucleus accumbens, amygdala, and cerebellar cortex. Because ASIC1 levels were particularly high in the amygdala, we focused further on this area. We found that extracellular acidosis elicited a greater current density in amygdala neurons than hippocampal neurons and that disrupting the ASIC1 gene eliminated H+-evoked currents in the amygdala. We also tested the effect of ASIC1 on amygdala-dependent behavior; ASIC1-null mice displayed deficits in cue and context fear conditioning, yet baseline fear on the elevated plus maze was intact. These studies suggest that ASIC1 is distributed to regions supporting high levels of synaptic plasticity and contributes to the neural mechanisms of fear conditioning.