The Impact of Parallel Fiber Background Activity on the Cable Properties of Cerebellar Purkinje Cells

1999 ◽  
Keyword(s):  
Purkinje Cells ◽  
Background Activity ◽  
Parallel Fiber ◽  
Cable Properties ◽  
Cerebellar Purkinje Cells ◽  
The Impact

Postsynaptic Current Mediated by Metabotropic Glutamate Receptors in Cerebellar Purkinje Cells

1998 ◽  
Vol 80 (2) ◽  
pp. 520-528 ◽  
Author(s):  
Filippo Tempia ◽  
Maria Concetta Miniaci ◽  
Davide Anchisi ◽  
Piergiorgio Strata
Keyword(s):  
Glutamate Receptors ◽  
Purkinje Cells ◽  
Metabotropic Glutamate Receptors ◽  
Parallel Fiber ◽  
High Concentration ◽  
Metabotropic Glutamate ◽  
Group I ◽  
Cerebellar Purkinje Cells ◽  
Mglur Antagonist ◽  
Fiber Stimulation

Tempia, Filippo, Maria Concetta Miniaci, Davide Anchisi, and Piergiorgio Strata. Postsynaptic current mediated by metabotropic glutamate receptors in cerebellar Purkinje cells. J. Neurophysiol. 80: 520–528, 1998. In rat cerebellar slices, repetitive parallel fiber stimulation evokes an inward, postsynaptic current in Purkinje cells with a fast component mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors and a slower component mediated by metabotropic glutamate receptors (mGluR). The mGluR-mediated excitatory postsynaptic current (mGluR-EPSC) is evoked selectively by parallel fiber stimulation; climbing fiber stimulation is ineffective. The mGluR-EPSC is elicited most effectively with increasing frequencies of parallel fiber stimulation, from a threshold of 10 Hz to a maximum response at ∼100 Hz. The amplitude of the mGluR-EPSC is a linear function of the number of stimulus pulses without any apparent saturation, even with >10 pulses. Thus mGluRs at the parallel fiber-Purkinje cell synapse can function as linear detectors of the number of spikes in a burst of activity in parallel fibers. The mGluR-EPSC is present from postnatal day 15 and persists into adulthood. It is inhibited by the generic mGluR antagonist (RS)-a-methyl-4-carboxyphenylglycine and by the group I mGluR antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid at a concentration selective for mGluR1. Although the intracellular transduction pathway involves a G protein, the putative mediators of mGluR1 (phospholipase C and protein kinase C) are not directly involved, indicating that the mGluR-EPSC studied here is mediated by a different and still unidentified second-messenger pathway. Heparin, a nonselective antagonist of inositol-trisphosphate (IP3) receptors, has no significant effect on the mGluR-EPSC, suggesting that also IP3 might be not required for the response. Buffering intracellular Ca2+ with a high concentration of bis-( o-aminophenoxy)- N,N,N′,N′-tetraacetic acid partially inhibits the mGluR-EPSC, indicating that Ca2+ is not directly responsible for the response but that resting Ca2+ levels exert a tonic potentiating effect on the mGluR-EPSC.

scholarly journals Cerebellar Purkinje cell activity modulates aggressive behavior

2020 ◽  
Author(s):  
Skyler L. Jackman ◽  
Christopher H. Chen ◽  
Heather L. Offermann ◽  
Iain R. Drew ◽  
Bailey M. Harrison ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Aggressive Behavior ◽  
Purkinje Cells ◽  
Motor Function ◽  
Cell Activity ◽  
Cerebellar Vermis ◽  
Cognitive Behaviors ◽  
Affective Behaviors ◽  
Cerebellar Purkinje Cells ◽  
The Impact

AbstractAlthough the cerebellum is traditionally associated with balance and motor function, it also plays wider roles in affective and cognitive behaviors. Evidence suggests that the cerebellar vermis may regulate aggressive behavior, though the cerebellar circuits and patterns of activity that influence aggression remain unclear. We used optogenetic methods to bidirectionally modulate the activity of spatially-delineated cerebellar Purkinje cells to evaluate the impact on aggression in mice. Increasing Purkinje cell activity in the vermis significantly reduced the frequency of attacks in a resident-intruder assay. Reduced aggression was not a consequence of impaired motor function, because optogenetic stimulation did not alter motor performance. In complementary experiments, optogenetic inhibition of Purkinje cells in the vermis increased the frequency of attacks. These results establish Purkinje cell activity in the cerebellar vermis regulates aggression, and further support the importance of the cerebellum in driving affective behaviors that could contribute to neurological disorders.

The Impact of Parallel Fiber Background Activity on the Cable Properties of Cerebellar Purkinje Cells

1992 ◽  
Vol 4 (4) ◽  
pp. 518-533 ◽  
Author(s):  
Moshe Rapp ◽  
Yosef Yarom ◽  
Idan Segev
Keyword(s):  
Background Activity ◽  
Large Population ◽  
Dendritic Tree ◽  
Reversal Potential ◽  
Membrane Conductance ◽  
Firing Frequency ◽  
Synaptic Activity ◽  
Synaptic Inputs ◽  
Cable Properties ◽  
The Impact

Neurons in the mammalian CNS receive 104-105 synaptic inputs onto their dendritic tree. Each of these inputs may fire spontaneously at a rate of a few spikes per second. Consequently, the cell is bombarded by several hundred synapses in each and every millisecond. An extreme example is the cerebellar Purkinje cell (PC) receiving approximately 100,000 excitatory synapses from the parallel fibers (p.f.s) onto dendritic spines covering the thin dendritic branchlets. What is the effect of the p.f.s activity on the integrative capabilities of the PC? This question is explored theoretically using analytical cable models as well as compartmental models of a morphologically and physiologically characterized PC from the guinea pig cerebellum. The input of individual p.f.s was modeled as a transient conductance change, peaking at 0.4 nS with a rise time of 0.3 msec and a reversal potential of +60 mV relative to rest. We found that already at a firing frequency of a few spikes per second the membrane conductance is several times larger than the membrane conductance in the absence of synaptic activity. As a result, the cable properties of the PC significantly change; the most sensitive parameters are the system time constant (τ0) and the steady-state attenuation factor from dendritic terminal to soma. The implication is that the cable properties of central neurons in freely behaving animals are different from those measured in slice preparation or in anesthetized animals, where most of the synaptic inputs are inactive. We conclude that, because of the large conductance increase produced by the background activity of the p.f.s, the activity of the PC will be altered from this background level either when the p.f.s change their firing frequency for a period of several tens of milliseconds or when a large population of the p.f.s fires during a narrow time window.

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