A Cerebellar Computational Mechanism for Delay Conditioning at Precise Time Intervals

The cerebellum is known to have an important role in sensing and execution of precise time intervals, but the mechanism by which arbitrary time intervals can be recognized and replicated with high precision is unknown. We propose a computational model in which precise time intervals can be identified from the pattern of individual spike activity in a population of parallel fibers in the cerebellar cortex. The model depends on the presence of repeatable sequences of spikes in response to conditioned stimulus input. We emulate granule cells using a population of Izhikevich neuron approximations driven by random but repeatable mossy fiber input. We emulate long-term depression (LTD) and long-term potentiation (LTP) synaptic plasticity at the parallel fiber to Purkinje cell synapse. We simulate a delay conditioning paradigm with a conditioned stimulus (CS) presented to the mossy fibers and an unconditioned stimulus (US) some time later issued to the Purkinje cells as a teaching signal. We show that Purkinje cells rapidly adapt to decrease firing probability following onset of the CS only at the interval for which the US had occurred. We suggest that detection of replicable spike patterns provides an accurate and easily learned timing structure that could be an important mechanism for behaviors that require identification and production of precise time intervals.

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Effect of tolbutamide on tetraethylammonium-induced postsynaptic zinc signals at hippocampal mossy fiber-CA3 synapses

Canadian Journal of Physiology and Pharmacology ◽

10.1139/cjpp-2016-0379 ◽

2017 ◽

Vol 95 (9) ◽

pp. 1058-1063 ◽

Cited By ~ 1

Author(s):

Fatima C. Bastos ◽

Vanessa N. Corceiro ◽

Sandra A. Lopes ◽

José G. de Almeida ◽

Carlos M. Matias ◽

...

Keyword(s):

Mossy Fiber ◽

Mossy Fibers ◽

Pyramidal Cells ◽

Long Term Potentiation ◽

Chemical Stimulation ◽

Term Potentiation ◽

Voltage Dependent ◽

Zinc Release ◽

Ca3 Pyramidal Cells

The application of tetraethylammonium (TEA), a blocker of voltage-dependent potassium channels, can induce long-term potentiation (LTP) in the synaptic systems CA3–CA1 and mossy fiber-CA3 pyramidal cells of the hippocampus. In the mossy fibers, the depolarization evoked by extracellular TEA induces a large amount of glutamate and also of zinc release. It is considered that zinc has a neuromodulatory role at the mossy fiber synapses, which can, at least in part, be due to the activation of presynaptic ATP-dependent potassium (KATP) channels. The aim of this work was to study properties of TEA-induced zinc signals, detected at the mossy fiber region, using the permeant form of the zinc indicator Newport Green. The application of TEA caused a depression of those signals that was partially blocked by the KATP channel inhibitor tolbutamide. After the removal of TEA, the signals usually increased to a level above baseline. These results are in agreement with the idea that intense zinc release during strong synaptic events triggers a negative feedback action. The zinc depression, caused by the LTP-evoking chemical stimulation, turns into potentiation after TEA washout, suggesting the existence of a correspondence between the observed zinc potentiation and TEA-evoked mossy fiber LTP.

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Effect of Conditioned Stimulus Parameters on Timing of Conditioned Purkinje Cell Responses

Journal of Neurophysiology ◽

10.1152/jn.00524.2009 ◽

2010 ◽

Vol 103 (3) ◽

pp. 1329-1336 ◽

Cited By ~ 20

Author(s):

Pär Svensson ◽

Dan-Anders Jirenhed ◽

Fredrik Bengtsson ◽

Germund Hesslow

Keyword(s):

Conditioned Stimulus ◽

Purkinje Cell ◽

Purkinje Cells ◽

Mossy Fiber ◽

Eyeblink Conditioning ◽

Mossy Fibers ◽

Inhibitory Response ◽

Cell Responses ◽

Cerebellar Purkinje Cells ◽

Adaptive Timing

Pavlovian eyeblink conditioning is a useful experimental model for studying adaptive timing, an important aspect of skilled movements. The conditioned response (CR) is precisely timed to occur just before the onset of the expected unconditioned stimulus (US). The timing can be changed immediately, however, by varying parameters of the conditioned stimulus (CS). It has previously been shown that increasing the intensity of a peripheral CS or the frequency of a CS consisting of a train of stimuli to the mossy fibers shortens the latency of the CR. The adaptive timing of behavioral CRs probably reflects the timing of an underlying learned inhibitory response in cerebellar Purkinje cells. It is not known how the latency of this Purkinje cell CR is controlled. We have recorded form Purkinje cells in conditioned decerebrate ferrets while increasing the intensity of a peripheral CS or the frequency of a mossy fiber CS. We observe changes in the timing of the Purkinje cell CR that match the behavioral effects. The results are consistent with the effect of CS parameters on behavioral CR latency being caused by corresponding changes in Purkinje cell CRs. They suggest that synaptic temporal summation may be one of several mechanisms underlying adaptive timing of movements.

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Exploring the Social Link between Cerebral and Cerebellar Neural Ensembles through a Falsifiable Psychological Heuristics

International Journal of Social Science Studies ◽

10.11114/ijsss.v6i2.2934 ◽

2018 ◽

Vol 6 (2) ◽

pp. 69

Author(s):

Antonio Cassella

Keyword(s):

Purkinje Cells ◽

Quantum Coherence ◽

Granule Cells ◽

Cerebellar Granule Cells ◽

Long Term Potentiation ◽

Quantum Decoherence ◽

The Third ◽

Neural Ensembles ◽

The Social

This article wields the logos psychological heuristics in proposing that the universe, the social brain, and subatomic ensembles sustain the journey of the Mesoamerican demigod Quetzalcoatl. Within quantum coherence, the going “coatl-quetzal” marries in the hyperspace of our 5000 microcomplexes the legitimacy (probability = p = 1) of the autistic “coatl” (“serpent”), guarded by the 2 000 000 cortical columns in the cerebral cortex, with the illegitimacy (p = 0) of the schizophrenic “quetzal” (“bird”) lodged in the cerebellar cortex. Within quantum decoherence, the return of “quetzal-coatl” to the cerebral coatl in spacetime reflects our escape from madness with a new piece of knowledge. At the turn of the 20th century, the author found that autistics’ strength in Performance IQ agrees with the victory of repetitive legitimacy over unexpected illegitimacy in the first attention. He concluded that autistics’ weakness in verbal IQ agrees with a damaged qubit |1› and |0› (ket one and ket zero) in the going journey of Quetzalcoatl with the second attention. At the turn of the first decade of the 21st century, the author researched the reciprocal empowerment of the first and the second attention in the Third Attention. Here he emphasizes that in spontaneous laughing, the coherence of long-term potentiation in cerebellar granule cells, parallel fibers, and Purkinje cells is followed by the decoherence of long-term depression in the fewer Purkinje cells that carry Quetzalcoatl and the Third Attention into the deep nuclei of the cerebellum, and then into the spacetime of a refreshed first attention.

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Roles of Metabotropic and Ionotropic Glutamate Receptors in the Long-Term Potentiation of Hippocampal Mossy Fiber Synapses

Excitatory Amino Acids and Neuronal Plasticity - Advances in Experimental Medicine and Biology ◽

10.1007/978-1-4684-5769-8_42 ◽

1990 ◽

pp. 387-394 ◽

Cited By ~ 2

Author(s):

Hiroyuki Sugiyama ◽

Isao Ito ◽

Daisuke Okada

Keyword(s):

Glutamate Receptors ◽

Mossy Fiber ◽

Long Term Potentiation ◽

Ionotropic Glutamate Receptors ◽

Term Potentiation

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Efficient generation of reciprocal signals by inhibition

Journal of Neurophysiology ◽

10.1152/jn.00083.2012 ◽

2012 ◽

Vol 107 (9) ◽

pp. 2453-2462 ◽

Cited By ~ 11

Author(s):

Sung-min Park ◽

Esra Tara ◽

Kamran Khodakhah

Keyword(s):

Purkinje Cells ◽

Granule Cell ◽

Granule Cells ◽

Mossy Fiber ◽

Cell Activity ◽

Common Mechanism ◽

Input Output ◽

Firing Rates ◽

Neuronal Computation ◽

The Brain

Reciprocal activity between populations of neurons has been widely observed in the brain and is essential for neuronal computation. The different mechanisms by which reciprocal neuronal activity is generated remain to be established. A common motif in neuronal circuits is the presence of afferents that provide excitation to one set of principal neurons and, via interneurons, inhibition to a second set of principal neurons. This circuitry can be the substrate for generation of reciprocal signals. Here we demonstrate that this equivalent circuit in the cerebellar cortex enables the reciprocal firing rates of Purkinje cells to be efficiently generated from a common set of mossy fiber inputs. The activity of a mossy fiber is relayed to Purkinje cells positioned immediately above it by excitatory granule cells. The firing rates of these Purkinje cells increase as a linear function of mossy fiber, and thus granule cell, activity. In addition to exciting Purkinje cells positioned immediately above it, the activity of a mossy fiber is relayed to laterally positioned Purkinje cells by a disynaptic granule cell → molecular layer interneuron pathway. Here we show in acutely prepared cerebellar slices that the input-output relationship of these laterally positioned Purkinje cells is linear and reciprocal to the first set. A similar linear input-output relationship between decreases in Purkinje cell firing and strength of stimulation of laterally positioned granule cells was also observed in vivo. Use of interneurons to generate reciprocal firing rates may be a common mechanism by which the brain generates reciprocal signals.

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