scholarly journals Patterned expression of Pannexin 1 channels in the adult cerebellar Purkinje cells

2018 ◽  
Author(s):  
Visou Ady ◽  
David Dubayle ◽  
Pascale Le Blanc ◽  
Valery Shestopalov ◽  
Claude Meunier ◽  
...  
Keyword(s):  
Cell Death ◽  
Purkinje Cells ◽  
Cell Communication ◽  
Cerebellar Nuclei ◽  
Modular Architecture ◽  
Pannexin 1 ◽  
Zebrin Ii ◽  
Dependent Cell ◽  
Cerebellar Purkinje Cells ◽  
Ensemble Activity

AbstractPannexin1 (PanX1) are recently discovered proteins that can form large pore channels at the cell surface. They have been implicated in ATP-dependent cell-to-cell communication and in several pathophysiological processes such as inflammation, cell death and epilepsy. Using immunohistochemistry in the adult mouse, we describe the presence of PanX1 in the deep cerebellar nuclei, in large cells of the granular layer, presumably Golgi interneurones, in some Bergmann glia radial processes as well as in the soma and dendrites of Purkinje cells. In the latter, PanX1, like many other proteins, distribute heterogeneously. Only Zebrin II-positive Purkinje cells express PanX1, in accordance with the so-called “zebra-striped” modular architecture of the cerebellum. This distribution in zebra-stripes suggest that PanX1 may contribute to the control of ensemble activity within cerebellar microdomains or to the response of Purkinje cell to excitotoxicity and cell-death messages.

Zebrin II Expression in the Cerebellum of a Paleognathous Bird, the Chilean Tinamou (Nothoprocta perdicaria)

2015 ◽  
Vol 85 (2) ◽  
pp. 94-106 ◽  
Author(s):  
Jeremy R. Corfield ◽  
Jeffery Kolominsky ◽  
Gonzalo J. Marin ◽  
Iulia Craciun ◽  
Bridget E. Mulvany-Robbins ◽  
...  
Keyword(s):  
Purkinje Cells ◽  
Expression Patterns ◽  
Bird Species ◽  
Glycolytic Enzyme ◽  
Anterior Region ◽  
Zebrin Ii ◽  
Expression Studies ◽  
General Similarity ◽  
Cerebellar Purkinje Cells ◽  
Nothoprocta Perdicaria

Zebrin II (ZII) is a glycolytic enzyme expressed in cerebellar Purkinje cells. In both mammals and birds, ZII is expressed heterogeneously, such that there are sagittal stripes of Purkinje cells with a high ZII expression (ZII+) alternating with stripes of Purkinje cells with little or no expression (ZII-). To date, ZII expression studies are limited to neognathous birds: pigeons (Columbiformes), chickens (Galliformes), and hummingbirds (Trochilidae). These previous studies divided the avian cerebellum into 5 transverse regions based on the pattern of ZII expression. In the lingular region (lobule I) all Purkinje cells are ZII+. In the anterior region (lobules II-V) there are 4 pairs of ZII+/- stripes. In the central region (lobules VI-VIII) all Purkinje cells are ZII+. In the posterior region (lobules VIII-IX) there are 5-7 pairs of ZII+/- stripes. Finally, in the nodular region (lobule X) all Purkinje cells are ZII+. As the pattern of ZII stripes is quite similar in these disparate species, it appears that it is highly conserved. However, it has yet to be studied in paleognathous birds, which split from the neognaths over 100 million years ago. To better understand the evolution of cerebellar compartmentation in birds, we examined ZII immunoreactivity in a paleognath, the Chilean tinamou (Nothoprocta perdicaria). In the tinamou, Purkinje cells expressed ZII heterogeneously such that there were sagittal ZII+ and ZII- stripes of Purkinje cells, and this pattern of expression was largely similar to that observed in neognathous birds. For example, all Purkinje cells in the lingular (lobule I) and nodular (lobule X) regions were ZII+, and there were 4 pairs of ZII+/- stripes in the anterior region (lobules II-V). In contrast to neognaths, however, ZII was expressed in lobules VI-VII as a series of sagittal stripes in the tinamou. Also unlike in neognaths, stripes were absent in lobule IXab, and all Purkinje cells expressed ZII in the tinamou. The differences in ZII expression between the tinamou and neognaths could reflect behavior, but the general similarity of the expression patterns across all bird species suggests that ZII stripes evolved early in the avian phylogenetic tree.

scholarly journals Disrupted Calcium Signaling in Animal Models of Human Spinocerebellar Ataxia (SCA)

2019 ◽  
Vol 21 (1) ◽  
pp. 216 ◽  
Author(s):  
Francesca Prestori ◽  
Francesco Moccia ◽  
Egidio D’Angelo
Keyword(s):  
Animal Models ◽  
Purkinje Cell ◽  
Calcium Signaling ◽  
Purkinje Cells ◽  
Motor Coordination ◽  
Cerebellar Atrophy ◽  
Cerebellar Nuclei ◽  
Spinocerebellar Ataxias ◽  
Cell Degeneration ◽  
Cerebellar Purkinje Cells

Spinocerebellar ataxias (SCAs) constitute a heterogeneous group of more than 40 autosomal-dominant genetic and neurodegenerative diseases characterized by loss of balance and motor coordination due to dysfunction of the cerebellum and its efferent connections. Despite a well-described clinical and pathological phenotype, the molecular and cellular events that underlie neurodegeneration are still poorly undaerstood. Emerging research suggests that mutations in SCA genes cause disruptions in multiple cellular pathways but the characteristic SCA pathogenesis does not begin until calcium signaling pathways are disrupted in cerebellar Purkinje cells. Ca2+ signaling in Purkinje cells is important for normal cellular function as these neurons express a variety of Ca2+ channels, Ca2+-dependent kinases and phosphatases, and Ca2+-binding proteins to tightly maintain Ca2+ homeostasis and regulate physiological Ca2+-dependent processes. Abnormal Ca2+ levels can activate toxic cascades leading to characteristic death of Purkinje cells, cerebellar atrophy, and ataxia that occur in many SCAs. The output of the cerebellar cortex is conveyed to the deep cerebellar nuclei (DCN) by Purkinje cells via inhibitory signals; thus, Purkinje cell dysfunction or degeneration would partially or completely impair the cerebellar output in SCAs. In the absence of the inhibitory signal emanating from Purkinje cells, DCN will become more excitable, thereby affecting the motor areas receiving DCN input and resulting in uncoordinated movements. An outstanding advantage in studying the pathogenesis of SCAs is represented by the availability of a large number of animal models which mimic the phenotype observed in humans. By mainly focusing on mouse models displaying mutations or deletions in genes which encode for Ca2+ signaling-related proteins, in this review we will discuss the several pathogenic mechanisms related to deranged Ca2+ homeostasis that leads to significant Purkinje cell degeneration and dysfunction.

scholarly journals Molecular Identity and Location Influence Purkinje Cell Vulnerability in Autosomal-Recessive Spastic Ataxia of Charlevoix-Saguenay Mice

2021 ◽  
Vol 15 ◽  
Author(s):  
Brenda Toscano Márquez ◽  
Anna A. Cook ◽  
Max Rice ◽  
Alexia Smileski ◽  
Kristen Vieira-Lomasney ◽  
...  
Keyword(s):  
Cell Death ◽  
Purkinje Cell ◽  
Purkinje Cells ◽  
Autosomal Recessive ◽  
Disease Onset ◽  
Cerebellar Nuclei ◽  
Spastic Ataxia ◽  
Molecular Identity ◽  
Purkinje Cell Death ◽  
Disease Stages

Patterned cell death is a common feature of many neurodegenerative diseases. In patients with autosomal-recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) and mouse models of ARSACS, it has been observed that Purkinje cells in anterior cerebellar vermis are vulnerable to degeneration while those in posterior vermis are resilient. Purkinje cells are known to express certain molecules in a highly stereotyped, patterned manner across the cerebellum. One patterned molecule is zebrin, which is expressed in distinctive stripes across the cerebellar cortex. The different zones delineated by the expression pattern of zebrin and other patterned molecules have been implicated in the patterning of Purkinje cell death, raising the question of whether they contribute to cell death in ARSACS. We found that zebrin patterning appears normal prior to disease onset in Sacs–/– mice, suggesting that zebrin-positive and -negative Purkinje cell zones develop normally. We next observed that zebrin-negative Purkinje cells in anterior lobule III were preferentially susceptible to cell death, while anterior zebrin-positive cells and posterior zebrin-negative and -positive cells remained resilient even at late disease stages. The patterning of Purkinje cell innervation to the target neurons in the cerebellar nuclei (CN) showed a similar pattern of loss: neurons in the anterior CN, where inputs are predominantly zebrin-negative, displayed a loss of Purkinje cell innervation. In contrast, neurons in the posterior CN, which is innervated by both zebrin-negative and -positive puncta, had normal innervation. These results suggest that the location and the molecular identity of Purkinje cells determine their susceptibility to cell death in ARSACS.

scholarly journals Climbing fiber synapses rapidly inhibit neighboring Purkinje cells via ephaptic coupling

2019 ◽  
Author(s):  
Kyung-Seok Han ◽  
Christopher H. Chen ◽  
Mehak M. Khan ◽  
Chong Guo ◽  
Wade G. Regehr
Keyword(s):  
Purkinje Cells ◽  
Inferior Olive ◽  
Cerebellar Nuclei ◽  
Extracellular Signals ◽  
Distance Dependence ◽  
Cerebellar Purkinje Cells ◽  
Motor Thalamus ◽  
Complex Spikes ◽  
Ephaptic Coupling

AbstractClimbing fibers (CFs) from the inferior olive (IO) provide strong excitatory inputs onto the dendrites of cerebellar Purkinje cells (PC), and trigger distinctive responses known as complex spikes (CSs). We find that in awake, behaving mice, a CS in one PC suppresses conventional simple spikes (SSs) in neighboring PCs for several milliseconds. This involves a novel form of ephaptic coupling, in which an excitatory synapse nonsynaptically inhibits neighboring cells by generating large negative extracellular signals near their dendrites. The distance dependence of CS-SS ephaptic signaling, combined with the known divergence of CF synapses made by IO neurons, allows a single IO neuron to influence the output of the cerebellum by synchronously suppressing the firing of potentially over one hundred PCs. Optogenetic studies in vivo and dynamic clamp studies in slice indicate that such brief PC suppression can effectively promote firing in neurons in the deep cerebellar nuclei and motor thalamus.

scholarly journals Calcium imaging reveals coordinated simple spike pauses in populations of Cerebellar Purkinje cells

2016 ◽  
Author(s):  
Jorge E. Ramirez ◽  
Brandon M. Stell
Keyword(s):  
Purkinje Cell ◽  
Purkinje Cells ◽  
Calcium Imaging ◽  
Spatial Organization ◽  
Cell Activity ◽  
Cerebellar Nuclei ◽  
Deep Cerebellar Nuclei ◽  
Firing Rates ◽  
Simple Spike ◽  
Cerebellar Purkinje Cells

The brain’s control of movement is thought to involve coordinated activity between cerebellar Purkinje cells. The results reported here demonstrate that somatic Ca2+ imaging is a faithful reporter of Na+-dependent “simple spike” pauses and enables us to optically record changes in firing rates in populations of Purkinje cells. This simultaneous calcium imaging of populations of Purkinje cells reveals a striking spatial organization of pauses in Purkinje cell activity between neighboring cells. The source of this organization is shown to be the presynaptic GABAergic network and blocking GABAARs abolishes the synchrony. These data suggest that presynaptic interneurons synchronize (in)activity between neighboring Purkinje cells and thereby maximize their effect on downstream targets in the deep cerebellar nuclei.

Zebrin Expression in the Cerebellum of Two Crocodilian Species

2020 ◽  
Vol 95 (1) ◽  
pp. 45-55
Author(s):  
Cristián  Gutiérrez-Ibáñez  ◽  
Max R. Dannish ◽  
Tobias Kohl ◽  
Lutz  Kettler ◽  
Catherine E. Carr ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Purkinje Cells ◽  
Glycolytic Enzyme ◽  
Alligator Mississippiensis ◽  
Aldolase C ◽  
Zebrin Ii ◽  
Close Phylogenetic Relationship ◽  
Afferent Inputs ◽  
Sagittal Zones ◽  
Cerebellar Purkinje Cells

While in birds and mammals the cerebellum is a highly convoluted structure that consists of numerous transverse lobules, in most amphibians and reptiles it consists of only a single unfolded sheet. Orthogonal to the lobules, the cerebellum is comprised of sagittal zones that are revealed in the pattern of afferent inputs, the projection patterns of Purkinje cells, and Purkinje cell response properties, among other features. The expression of several molecular markers, such as aldolase C, is also parasagittally organized. Aldolase C, also known as zebrin II (ZII), is a glycolytic enzyme expressed in the cerebellar Purkinje cells of the vertebrate cerebellum. In birds, mammals, and some lizards (Ctenophoresspp.), ZII is expressed in a heterogenous fashion of alternating sagittal bands of high (ZII+) and low (ZII–) expression Purkinje cells. In contrast, turtles and snakes express ZII homogenously (ZII+) in their cerebella, but the pattern in crocodilians is unknown. Here, we examined the expression of ZII in two crocodilian species (Crocodylus niloticus and Alligator mississippiensis) to help determine the evolutionary origin of striped ZII expression in vertebrates. We expected crocodilians to express ZII in a striped (ZII+/ZII–) manner because of their close phylogenetic relationship to birds and their larger and more folded cerebellum compared to that of snakes and turtles. Contrary to our prediction, all Purkinje cells in the crocodilian cerebellum had a generally homogenous expression of ZII (ZII+) rather than clear ZII+/– stripes. Our results suggest that either ZII stripes were lost in three groups (snakes, turtles, and crocodilians) or ZII stripes evolved independently three times (lizards, birds, and mammals).

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