Center for Learning and Memory, University of Texas at Austin, 1 University Station, Austin, Texas 78712, USA.
J Neurophysiol. 2009 Oct;102(4):2288-302. doi: 10.1152/jn.00082.2009. Epub 2009 Aug 12.
The study of learning and memory at the single-neuron level has relied on the use of many animal models, most notably rodents. Although many physiological and anatomical studies have been carried out in rats, the advent of genetically engineered mice has necessitated the comparison of new results in mice to established results from rats. Here we compare fundamental physiological and morphological properties and create three-dimensional compartmental models of identified hippocampal CA1 pyramidal neurons of one strain of rat, Sprague-Dawley, and two strains of mice, C57BL/6 and 129/SvEv. We report several differences in neuronal physiology and anatomy among the three animal groups, the most notable being that neurons of the 129/SvEv mice, but not the C57BL/6 mice, have higher input resistance, lower dendritic surface area, and smaller spines than those of rats. A surprising species-specific difference in membrane resonance indicates that both mouse strains have lower levels of the hyperpolarization-activated nonspecific cation current I(h). Simulations suggest that differences in I(h) kinetics rather than maximal conductance account for the lower resonance. Our findings indicate that comparisons of data obtained across strains or species will need to account for these and potentially other physiological and anatomical differences.
在单细胞水平上研究学习和记忆一直依赖于许多动物模型的使用，其中最著名的是啮齿动物。尽管在大鼠中进行了许多生理学和解剖学研究，但基因工程小鼠的出现使得有必要将新的研究结果与大鼠的已有结果进行比较。在这里，我们比较了一种大鼠（Sprague-Dawley）和两种小鼠（C57BL/6 和 129/SvEv）的海马 CA1 锥体神经元的基本生理和形态特性，并建立了它们的三维室模型。我们报告了这三个动物群体之间的几个神经元生理学和解剖学差异，最显著的是 129/SvEv 小鼠的神经元比大鼠的具有更高的输入电阻、更小的树突表面积和更小的棘突，但 C57BL/6 小鼠的神经元则没有。膜共振的一个惊人的种特异性差异表明，两种小鼠品系的超极化激活非特异性阳离子电流 I(h)水平都较低。模拟表明，较低的共振是由 I(h)动力学的差异而不是最大电导的差异引起的。我们的研究结果表明，对不同品系或物种之间获得的数据进行比较时，将需要考虑到这些以及可能存在的其他生理和解剖学差异。
