Tang Tianyu, Xiao Jianqiang, Suh Colleen Y, Burroughs Amelia, Cerminara Nadia L, Jia Linjia, Marshall Sarah P, Wise Andrew K, Apps Richard, Sugihara Izumi, Lang Eric J
Department of Neuroscience and Physiology, New York University School of Medicine, New York, USA.
School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
J Physiol. 2017 Aug 1;595(15):5341-5357. doi: 10.1113/JP274252. Epub 2017 Jun 26.
Cerebellar Purkinje cells (PCs) generate two types of action potentials, simple and complex spikes. Although they are generated by distinct mechanisms, interactions between the two spike types exist. Zebrin staining produces alternating positive and negative stripes of PCs across most of the cerebellar cortex. Thus, here we compared simple spike-complex spike interactions both within and across zebrin populations. Simple spike activity undergoes a complex modulation preceding and following a complex spike. The amplitudes of the pre- and post-complex spike modulation phases were correlated across PCs. On average, the modulation was larger for PCs in zebrin positive regions. Correlations between aspects of the complex spike waveform and simple spike activity were found, some of which varied between zebrin positive and negative PCs. The implications of the results are discussed with regard to hypotheses that complex spikes are triggered by rises in simple spike activity for either motor learning or homeostatic functions.
Purkinje cells (PCs) generate two types of action potentials, called simple and complex spikes (SSs and CSs). We first investigated the CS-associated modulation of SS activity and its relationship to the zebrin status of the PC. The modulation pattern consisted of a pre-CS rise in SS activity, and then, following the CS, a pause, a rebound, and finally a late inhibition of SS activity for both zebrin positive (Z+) and negative (Z-) cells, though the amplitudes of the phases were larger in Z+ cells. Moreover, the amplitudes of the pre-CS rise with the late inhibitory phase of the modulation were correlated across PCs. In contrast, correlations between modulation phases across CSs of individual PCs were generally weak. Next, the relationship between CS spikelets and SS activity was investigated. The number of spikelets/CS correlated with the average SS firing rate only for Z+ cells. In contrast, correlations across CSs between spikelet numbers and the amplitudes of the SS modulation phases were generally weak. Division of spikelets into likely axonally propagated and non-propagated groups (based on their interspikelet interval) showed that the correlation of spikelet number with SS firing rate primarily reflected a relationship with non-propagated spikelets. In sum, the results show both zebrin-related and non-zebrin-related physiological heterogeneity in SS-CS interactions among PCs, which suggests that the cerebellar cortex is more functionally diverse than is assumed by standard theories of cerebellar function.
小脑浦肯野细胞（PCs）产生两种类型的动作电位，即简单峰电位和复合峰电位。尽管它们由不同的机制产生，但两种峰电位类型之间存在相互作用。斑马蛋白染色在大部分小脑皮质中产生PCs的正负交替条纹。因此，在这里我们比较了斑马蛋白群体内部和之间的简单峰电位 - 复合峰电位相互作用。简单峰电位活动在复合峰电位之前和之后经历复杂的调制。复合峰电位前后调制阶段的幅度在不同的PCs之间具有相关性。平均而言，斑马蛋白阳性区域的PCs的调制更大。发现复合峰电位波形的各个方面与简单峰电位活动之间存在相关性，其中一些在斑马蛋白阳性和阴性PCs之间有所不同。关于复合峰电位由简单峰电位活动升高触发以实现运动学习或稳态功能的假设，讨论了结果的意义。
浦肯野细胞（PCs）产生两种类型的动作电位，称为简单峰电位和复合峰电位（SSs和CSs）。我们首先研究了与复合峰电位相关的简单峰电位活动调制及其与PCs的斑马蛋白状态的关系。调制模式包括复合峰电位之前简单峰电位活动的升高，然后，在复合峰电位之后，对于斑马蛋白阳性（Z +）和阴性（Z -）细胞，简单峰电位活动出现暂停、反弹，最后是晚期抑制，尽管在Z +细胞中各阶段的幅度更大。此外，复合峰电位之前升高的幅度与调制的晚期抑制阶段在不同的PCs之间具有相关性。相比之下，单个PCs的复合峰电位之间调制阶段的相关性通常较弱。接下来，研究了复合峰电位小尖峰与简单峰电位活动之间的关系。仅对于Z +细胞，小尖峰/复合峰电位的数量与平均简单峰电位发放率相关。相比之下，小尖峰数量与简单峰电位调制阶段幅度之间在复合峰电位之间的相关性通常较弱。将小尖峰分为可能轴突传播和非传播组（基于它们的小尖峰间隔）表明，小尖峰数量与简单峰电位发放率的相关性主要反映了与非传播小尖峰的关系。总之，结果表明在PCs之间的简单峰电位 - 复合峰电位相互作用中存在与斑马蛋白相关和与斑马蛋白无关的生理异质性，这表明小脑皮质在功能上比小脑功能的标准理论所假设的更加多样化。
