scholarly journals Synchronous spiking of cerebellar Purkinje cells during control of movements

2021 ◽  
Author(s):  
Ehsan Sedaghat-Nejad ◽  
Jay S. Pi ◽  
Paul Hage ◽  
Mohammad Amin Fakharian ◽  
Reza Shadmehr
Keyword(s):  
Purkinje Cells ◽  
Cerebellar Cortex ◽  
Saccadic Eye Movements ◽  
Spike Response ◽  
Spike Synchrony ◽  
Firing Rates ◽  
Output Neurons ◽  
Cerebellar Purkinje Cells ◽  
P Cells ◽  
Spike Firing

AbstractThe information that the brain transmits from one region to another is often viewed through the lens of firing rates. However, if the output neurons could vary the timing of their spikes with respect to each other, then through synchronization they could highlight information that may be critical for control of behavior. In the cerebellum, the computations that are performed by the cerebellar cortex are conveyed to the nuclei via inhibition. Yet, synchronous activity entrains nucleus neurons, making them fire. Does the cerebellar cortex rely on spike synchrony within populations of Purkinje cells (P-cells) to convey information to the nucleus? We recorded from multiple P-cells while marmosets performed saccadic eye movements and organized them into populations that shared a complex spike response to error. Before movement onset, P-cells transmitted information via a rate code: the simple spike firing rates predicted the direction and velocity of the impending saccade. However, during the saccade, the spikes became temporally aligned within the population, signaling when to stop the movement. Thus, the cerebellar cortex relies on spike synchronization within a population of P-cells, not individual firing rates, to convey to the nucleus when to stop a movement.

scholarly journals mGlu1 receptor mediates homeostatic control of intrinsic excitability through Ih in cerebellar Purkinje cells

2016 ◽  
Vol 115 (5) ◽  
pp. 2446-2455 ◽  
Author(s):  
Hyun Geun Shim ◽  
Sung-Soo Jang ◽  
Dong Cheol Jang ◽  
Yunju Jin ◽  
Wonseok Chang ◽  
...  
Keyword(s):  
Purkinje Cells ◽  
Neuronal Activity ◽  
Metabotropic Glutamate Receptor ◽  
Activity Level ◽  
Network Activity ◽  
Firing Rates ◽  
Metabotropic Glutamate ◽  
Gated Channel ◽  
Intrinsic Plasticity ◽  
Cerebellar Purkinje Cells

Homeostatic intrinsic plasticity is a cellular mechanism for maintaining a stable neuronal activity level in response to developmental or activity-dependent changes. Type 1 metabotropic glutamate receptor (mGlu1 receptor) has been widely known to monitor neuronal activity, which plays a role as a modulator of intrinsic and synaptic plasticity of neurons. Whether mGlu1 receptor contributes to the compensatory adjustment of Purkinje cells (PCs), the sole output of the cerebellar cortex, in response to chronic changes in excitability remains unclear. Here, we demonstrate that the mGlu1 receptor is involved in homeostatic intrinsic plasticity through the upregulation of the hyperpolarization-activated current ( Ih) in cerebellar PCs. This plasticity was prevented by inhibiting the mGlu1 receptor with Bay 36–7620, an mGlu1 receptor inverse agonist, but not with CPCCOEt, a neutral antagonist. Chronic inactivation with tetrodotoxin (TTX) increased the components of Ih in the PCs, and ZD 7288, a hyperpolarization-activated cyclic nucleotide-gated channel selective inhibitor, fully restored reduction of firing rates in the deprived neurons. The homeostatic elevation of Ih was also prevented by BAY 36–7620, but not CPCCOEt. Furthermore, KT 5720, a blocker of protein kinase A (PKA), prevented the effect of TTX reducing the evoked firing rates, indicating the reduction in excitability of PCs due to PKA activation. Our study shows that both the mGlu1 receptor and the PKA pathway are involved in the homeostatic intrinsic plasticity of PCs after chronic blockade of the network activity, which provides a novel understanding on how cerebellar PCs can preserve the homeostatic state under activity-deprived conditions.

Stochastic description of complex and simple spike firing in cerebellar Purkinje cells

2007 ◽  
Vol 25 (3) ◽  
pp. 785-794 ◽  
Author(s):  
Soon-Lim Shin ◽  
Stefan Rotter ◽  
Ad Aertsen ◽  
Erik De Schutter
Keyword(s):  
Purkinje Cells ◽  
Stochastic Description ◽  
Simple Spike ◽  
Cerebellar Purkinje Cells ◽  
Spike Firing

scholarly journals Apoptosis and Necrosis Occur in Separate Neuronal Populations in Hippocampus and Cerebellum after Ischemia and Are Associated with Differential Alterations in Metabotropic Glutamate Receptor Signaling Pathways

2000 ◽  
Vol 20 (1) ◽  
pp. 153-167 ◽  
Author(s):  
Lee J. Martin ◽  
Frederick E. Sieber ◽  
Richard J. Traystman
Keyword(s):  
Signaling Pathways ◽  
Purkinje Cells ◽  
Cerebellar Cortex ◽  
Metabotropic Glutamate Receptors ◽  
Pyramidal Neurons ◽  
Metabotropic Glutamate Receptor ◽  
Pyramidal Cells ◽  
Granule Neurons ◽  
Metabotropic Glutamate ◽  
Cerebellar Purkinje Cells

It was evaluated whether postischemic neurodegeneration is apoptosis and occurs with alterations in phosphoinositide-linked metabotropic glutamate receptors (mGluRs) and their associated signaling pathways. A dog model of transient global incomplete cerebral ischemia was used. The CA1 pyramidal cells and cerebellar Purkinje cells underwent progressive delayed degeneration. By in situ end-labeling of DNA, death of CA1 and Purkinje cells was greater at 7 days than 1 day after ischemia, whereas death of granule neurons in dentate gyrus and cerebellar cortex was greater at 1 than at 7 days. Ultrastructurally, degenerating CA1 pyramidal neurons and cerebellar Purkinje cells were necrotic; in contrast, degenerating granule neurons were apoptotic. In agarose gels of regional DNA extracts, random DNA fragmentation coexisted with internucleosomal fragmentation. By immunoblotting of regional homogenates, mGluR1α, mGluR5, phospholipase Cβ (PLCβ), and Gαq/11 protein levels in hippocampus at 1 and 7 days after ischemia were similar to control levels, but in cerebellar cortex, mGluR1α and mGluR5 were decreased but PLCβ was increased. By immunocytochemistry, mGluR and PLCβ immunoreactivity dissipated in CA1 and cerebellar Purkinje cell/ molecular layers, whereas immunoreactivities for these proteins were enhanced in granule neurons. It was concluded that neuronal death after global ischemia exists as two distinct, temporally overlapping forms in hippocampus and cerebellum: necrosis of pyramidal neurons and Purkinje cells and apoptosis of granule neurons. Neuronal necrosis is associated with a loss of phosphoinositide-linked mGluR transduction proteins, whereas neuronal apoptosis occurs with increased mGluR signaling.

scholarly journals Type-1 metabotropic glutamate receptor signaling in cerebellar Purkinje cells in health and disease

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 416 ◽  
Author(s):  
Masanobu Kano ◽  
Takaki Watanabe
Keyword(s):  
Purkinje Cells ◽  
Glutamate Receptor ◽  
Metabotropic Glutamate Receptor ◽  
Synaptic Response ◽  
Coordination Control ◽  
Metabotropic Glutamate ◽  
Health And Disease ◽  
Output Neurons ◽  
Cerebellar Purkinje Cells

The cerebellum is a brain structure involved in coordination, control, and learning of movements, as well as certain aspects of cognitive function. Purkinje cells are the sole output neurons from the cerebellar cortex and therefore play crucial roles in the overall function of the cerebellum. The type-1 metabotropic glutamate receptor (mGluR1) is a key “hub” molecule that is critically involved in the regulation of synaptic wiring, excitability, synaptic response, and synaptic plasticity of Purkinje cells. In this review, we aim to highlight how mGluR1 controls these events in Purkinje cells. We also describe emerging evidence that altered mGluR1 signaling in Purkinje cells underlies cerebellar dysfunctions in several clinically relevant mouse models of human ataxias.

scholarly journals Differential Purkinje cell simple spike activity and pausing behavior related to cerebellar modules

2015 ◽  
Vol 113 (7) ◽  
pp. 2524-2536 ◽  
Author(s):  
Haibo Zhou ◽  
Kai Voges ◽  
Zhanmin Lin ◽  
Chiheng Ju ◽  
Martijn Schonewille
Keyword(s):  
Purkinje Cell ◽  
Purkinje Cells ◽  
Cerebellar Cortex ◽  
Spike Activity ◽  
Vestibular Nuclei ◽  
Simple Spike ◽  
Transverse Zone ◽  
Cerebellar Modules ◽  
Lower Temperature ◽  
Cerebellar Purkinje Cells

The massive computational capacity of the cerebellar cortex is conveyed by Purkinje cells onto cerebellar and vestibular nuclei neurons through their GABAergic, inhibitory output. This implies that pauses in Purkinje cell simple spike activity are potentially instrumental in cerebellar information processing, but their occurrence and extent are still heavily debated. The cerebellar cortex, although often treated as such, is not homogeneous. Cerebellar modules with distinct anatomical connectivity and gene expression have been described, and Purkinje cells in these modules also differ in firing rate of simple and complex spikes. In this study we systematically correlate, in awake mice, the pausing in simple spike activity of Purkinje cells recorded throughout the entire cerebellum, with their location in terms of lobule, transverse zone, and zebrin-identified cerebellar module. A subset of Purkinje cells displayed long (>500-ms) pauses, but we found that their occurrence correlated with tissue damage and lower temperature. In contrast to long pauses, short pauses (<500 ms) and the shape of the interspike interval (ISI) distributions can differ between Purkinje cells of different lobules and cerebellar modules. In fact, the ISI distributions can differ both between and within populations of Purkinje cells with the same zebrin identity, and these differences are at least in part caused by differential synaptic inputs. Our results suggest that long pauses are rare but that there are differences related to shorter intersimple spike intervals between and within specific subsets of Purkinje cells, indicating a potential further segregation in the activity of cerebellar Purkinje cells.

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.

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