Carlton Susan M, Hargett Gregory L
Department of Anatomy and Neurosciences, Marine Biomedical Institute, University of Texas Medical Branch, Galveston, Texas 77555-1069, USA.
J Comp Neurol. 2002 Jun 17;448(1):102-10. doi: 10.1002/cne.10250.
The enzyme Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is widely distributed in the nervous system. A previous report describes immunostaining for CaMKII alpha in dorsal root ganglion (DRG) neurons. In this study, CaMKII alpha is colocalized in the rat with three putative markers of nociceptive DRG neurons, isolectin Griffonia simplicifolia (I-B4), identifying small-diameter, "peptide-poor" neurons; calcitonin gene-related peptide (CGRP), identifying " peptide-rich" neurons; or the vanilloid receptor 1 (VR1), identifying neurons activated by heat, acid, and capsaicin. Lumbar 4 and 5 DRG sections were labeled using immunofluorescence or lectin binding histochemistry, and percentages of single and double-labeled CaMKIIalpha neurons were determined. Stereological estimates of total neuron number in the L4 DRG were 13,815 +/- 2,798 and in the L5 DRG were 14,111 +/- 4,043. Percentages of single-labeled L4 DRG neurons were 41% +/- 2% CaMKII alpha, 38% +/- 3% I-B4, 44% +/- 3% CGRP, and 32% +/- 6% VR1. Percentages of single-labeled L5 DRG neurons were 44% +/- 5% CaMKII alpha, 48% +/- 2% I-B4, 41% +/- 7% CGRP, and 39% +/- 14% VR1. For L4 and L5, respectively, estimates of double-labeled CaMKII alpha neurons showed 34% +/- 2% and 38% +/- 17% labeled for I-B4, 25% +/- 14% and 19% +/- 10% labeled for CGRP, and 37% +/- 7% and 38% +/- 5% labeled for VR1. Conversely, for L4 and L5, respectively, 39% +/- 14% and 38% +/- 7% I-B4 binding neurons, 24% +/- 12% and 23% +/- 10% CGRP neurons, and 42% +/- 7% and 35% +/- 7% VR1 neurons labeled for CaMKIIalpha. The mean diameter of CaMKII alpha - labeled neurons was approximately 27 microm, confirming that this enzyme was preferentially localized in small DRG neurons. The results indicate that subpopulations of DRG neurons containing CaMKII alpha are likely to be involved in the processing of nociceptive information. Thus, this enzyme may play a critical role in the modulation of nociceptor activity and plasticity of primary sensory neurons.
钙/钙调蛋白依赖性蛋白激酶II（CaMKII）广泛分布于神经系统。先前的一份报告描述了背根神经节（DRG）神经元中CaMKIIα的免疫染色情况。在本研究中，CaMKIIα在大鼠体内与伤害性DRG神经元的三种假定标志物共定位，即红豆蔻凝集素（I-B4），可识别小直径、“肽含量低”的神经元；降钙素基因相关肽（CGRP），可识别“肽含量高”的神经元；或香草酸受体1（VR1），可识别被热、酸和辣椒素激活的神经元。使用免疫荧光或凝集素结合组织化学对腰4和腰5 DRG切片进行标记，并确定单标记和双标记CaMKIIα神经元的百分比。L4 DRG中神经元总数的体视学估计为13,815±2,798，L5 DRG中为14,111±4,043。L4 DRG单标记神经元的百分比分别为41%±2% CaMKIIα、38%±3% I-B4、44%±3% CGRP和32%±6% VR1。L5 DRG单标记神经元的百分比分别为44%±5% CaMKIIα、48%±2% I-B4、41%±7% CGRP和39%±14% VR1。对于L4和L5，双标记CaMKIIα神经元的估计显示，分别有34%±2%和38%±17%被I-B4标记，25%±14%和19%±10%被CGRP标记，37%±7%和38%±5%被VR1标记。相反，对于L4和L5，分别有39%±14%和38%±7%的I-B4结合神经元、24%±12%和23%±10%的CGRP神经元以及42%±7%和35%±7%的VR1神经元被CaMKIIα标记。CaMKIIα标记神经元的平均直径约为27微米，证实该酶优先定位于小DRG神经元中。结果表明，含有CaMKIIα的DRG神经元亚群可能参与伤害性信息的处理。因此，这种酶可能在伤害感受器活性的调节和初级感觉神经元的可塑性中起关键作用。
