Abraham Preetha Anna, Xing Guoqiang, Zhang Lei, Yu Eric Z, Post Robert, Gamble Eleanore H, Li He
Center for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814, USA.
Brain Res. 2008 May 13;1209:65-73. doi: 10.1016/j.brainres.2008.02.082. Epub 2008 Mar 8.
The expression and characteristics of beta-adrenoceptor subtypes (beta1 and beta2) and their agonist actions on synaptic transmission in the basolateral amygdala (BLA) of the rat were examined using in situ hybridization, quantitative real-time PCR, Western blot analysis and field potential recording. In situ hybridization data revealed an intense distribution of beta1-and beta2-adrenoceptor mRNA in the BLA. Real-time PCR analysis of rat amygdala revealed significant transcriptional expression levels of both beta-adrenoceptors, with beta2-adrenoceptors outnumbering beta1-adrenoceptors in a ratio of 2.9 to 1. Bath application of the selective beta1-adrenoceptor agonist xamoterol hemifumarate (10 microM) facilitated the excitatory field synaptic potential evoked in the BLA by stimulation of the external capsule by 186.5+/-10.7% of control amplitude. In the presence of the selective beta1-adrenoceptor antagonist betaxolol hydrochloride (30 microM), the facilitating effects of field excitatory synaptic potential induced by the agonist were reduced to 126.1+/-2.3 % of control amplitude in the BLA. Bath application of the selective beta2-adrenoceptor agonist salmeterol (15 microM) facilitated the excitatory field synaptic potential evoked in the BLA by stimulation of the external capsule by 167.3+/-9.7 % of control amplitude. In the presence of the selective beta2-adrenoceptor antagonist ICI 118,551 HCl (30 microM), the facilitating effects of field excitatory synaptic potential induced by the agonist were reduced to 121.1+/-4.1 % of control amplitude in the BLA. These data suggest that beta-adrenoceptor mediated synaptic facilitation in the amygdala is mediated by both beta1 and beta2-adrenoceptor activation.
利用原位杂交、定量实时聚合酶链反应、蛋白质免疫印迹分析和场电位记录，研究了大鼠基底外侧杏仁核（BLA）中β-肾上腺素能受体亚型（β1和β2）的表达、特征及其对突触传递的激动作用。原位杂交数据显示，β1和β2肾上腺素能受体mRNA在BLA中分布密集。对大鼠杏仁核的实时聚合酶链反应分析显示，两种β-肾上腺素能受体均有显著的转录表达水平，β2肾上腺素能受体与β1肾上腺素能受体的数量比为2.9比1。浴槽给药选择性β1肾上腺素能受体激动剂半富马酸醋丁洛尔（10微摩尔），可使刺激外囊诱发的BLA兴奋性场突触电位增强至对照幅度的186.5±10.7%。在存在选择性β1肾上腺素能受体拮抗剂盐酸倍他洛尔（30微摩尔）的情况下，激动剂诱导的场兴奋性突触电位的促进作用在BLA中降至对照幅度的126.1±2.3%。浴槽给药选择性β2肾上腺素能受体激动剂沙美特罗（15微摩尔），可使刺激外囊诱发的BLA兴奋性场突触电位增强至对照幅度的167.3±9.7%。在存在选择性β2肾上腺素能受体拮抗剂盐酸ICI 118,551（30微摩尔）的情况下，激动剂诱导的场兴奋性突触电位的促进作用在BLA中降至对照幅度的121.1±4.1%。这些数据表明，杏仁核中β-肾上腺素能受体介导的突触易化作用是由β1和β2肾上腺素能受体激活共同介导的。
