Quantitative Golgi study of the rat cerebellar molecular layer interneurons using principal component analysis

Abstract

In this study, we applied for the first time a multivariate analysis to describe the anatomy of cerebellar molecular layer interneurons. Forty variables extending over a variety of morphological features (geometrical, topological, and metrical) were obtained from a three-dimensional reconstruction of 26 rat rapid Golgi-stained neurons. The subsequent principal component analysis showed that the first principal component was strongly correlated with variables related to the depth of each cell's soma in the molecular layer. The second principal component was strongly correlated with parameters describing axonal morphology. Finally, an analysis of the distribution of these anatomical features suggested that these cells cannot be classified into distinct groups but, instead, represent one continuously varying population. Thus, the classical division of molecular layer neurons into deep basket cells and superficial stellate cells is not supported by our analysis. These results have important implications for the development of the cerebellar cortex as well as for the expected patterns of Purkinje cell activity following activation of the granule cell layer.

Synapse-Level Determination of Action Potential Duration by K + Channel Clustering in Axons

“…In cell-attached patches from SC boutons, we recorded K + currents mediated by both K v 1 and K v 3 type channels. The same current complement has also been reported for the pinceau axon specializations of cerebellar basket cells (Southan and Robertson, 2000), a closely related interneuron type in the molecular layer (Sultan and Bower, 1998). Although currents mediated by both K v 1 and K v 3 channels contribute to AP repolarization in the boutons of some cell types (Hoppa et al, 2014; Ritzau-Jost et al, 2014), we found that the conductance carried by K v 3-mediated currents predominates when driven by an AP-like waveform from a physiological resting membrane potential likely explaining why AP repolarization is determined by this channel type rather than K v 1 (Rowan et al, 2014).…”

In Vivo Calcium Imaging of Circuit Activity in Cerebellar Cortex

“…Stellate cell dendrites extend for several hundred micrometers sagittally, perpendicular to PF orientation (Palay and Chan-Palay 1974; Sultan and Bower 1998). Consistent with this anatomy, many responding interneurons were found well outside the region of PF beam activation.…”

Quantitative morphological study of microglial cells in the ischemic rat brain using principal component analysis

“…This method was successfully used in research on neuron morphology (e.g. Yelnik et al, 1983;Harpering et al, 1985;Pearson et al, 1985;Sultan and Bower, 1998;Sultan et al, 2003). PCA has some advantage over cluster analysis and other multivariate methods, as for example discriminant analysis.…”