The amygdala is a chemosensor that detects carbon dioxide and acidosis to elicit fear behavior (Cell, 2009, 139:1012-1021)

報告日期: 2010/06/18
報告時間: 15:10/16:20
報告學生: 邱全秀
講評老師: 簡伯武
附件下載:

 

Active reading format

 

http://basicmed.med.ncku.edu.tw/admin/up_img/990618-1.pdf

The amygdala is a chemosensor that detects carbon dioxide and acidosis to elicit fear behavior

Cell (2009) 139:1210-1021.

 

Speaker: Chiuan-Shiou Chiou

Commentator: A-Min Huang, Ph. D.

Time: 2010/06/18 15:10

Place: Room 602

 

Abstract

The amygdala processes and directs inputs and outputs that is the key to both the innate and acquired fear behavior. The acid-sensing ion channel-1a (ASIC1a) is particularly abundant in the amygdala and acquired for normal responses in tests of both conditioned and unconditioned fear behavior. ASICs are activated in vitro when extracellular pH falls. In this study, the authors hypothesized that ASIC1a in the amygdala would be activated by carbon dioxide inhalation and/or reduced pH to elicit fear behavior. The results showed that inhaled CO2 reduced brain pH without affecting the ventilation and activated ASIC1a channel in the amygdala to enhance fear memory when coupled with footshocks but not to act as an unconditioned stimulus. Elevating brain pH interfered with the ability of ASIC1a to promote fear learning and reduced innate fear response. Restoring ASIC1a expression bilaterally in the amygdala of ASIC1a-/- mice rescued CO2-evoked freezing. They concluded the amygdala is a chemosensor that detects carbon dioxide and acidosis to elicit fear behavior.

 

Reference

1.    Matthew W. Coryell etc., Targeting ASIC1a reduces innate fear and alters neuronal activity in the fear circuit, Biol Psychiatry 2007;62:1140-1148.

2.    John A. Wemmie etc., Acid-sensing ion channel 1 is localized in brain regions with high synaptic density and contributes to fear conditioning, J Neurosci 2003;23:5496-5502.