Department of Pharmacology, University of Wisconsin, School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA.
Neuroscience. 2010 May 5;167(2):247-55. doi: 10.1016/j.neuroscience.2010.02.022. Epub 2010 Feb 16.
The sigma-1 receptor regulates various ion channel activity and possesses protein chaperone function. Using an antibody against the full sequence of the sigma-1 receptor we detected immunostaining in wild type but not in knockout mice. The receptor was found primarily in motoneurons localized to the brainstem and spinal cord. At the subcellular level the receptor is restricted to large cholinergic postsynaptic densities on the soma of motoneurons and is colocalized with the Kv2.1 potassium channel and the muscarinic type 2 cholinergic receptor. Ultrastructural analysis of the neurons indicates that the immunostained receptor is located close but separate from the plasma membrane, possibly in subsurface cisternae formed from the endoplasmic reticulum (ER), which are a prominent feature of cholinergic postsynaptic densities. Behavioral testing on a rotorod revealed that Sigma-1 receptor knockout mice remained on the rotorod for significantly less time (a shorter latency period) compared to the wild type mice. Together these data indicate that the sigma-1 receptor may play a role in the regulation of motor behavior.
sigma-1 受体调节各种离子通道活性，并具有蛋白质伴侣功能。使用针对 sigma-1 受体全长序列的抗体，我们在野生型小鼠中检测到免疫染色，但在敲除型小鼠中未检测到。该受体主要存在于位于脑干和脊髓的运动神经元中。在亚细胞水平上，受体局限于运动神经元体上的大胆碱能突触后密度，并与 Kv2.1 钾通道和毒蕈碱型 2 胆碱能受体共定位。神经元的超微结构分析表明，免疫染色的受体位于靠近但与质膜分离的位置，可能位于内质网（ER）形成的胞质小凹中，这是胆碱能突触后密度的一个显著特征。在转棒上的行为测试表明，与野生型小鼠相比，Sigma-1 受体敲除型小鼠在转棒上的停留时间明显缩短（潜伏期更短）。这些数据表明，sigma-1 受体可能在运动行为的调节中发挥作用。
