scholarly journals Presynaptic CB1 Receptors Regulate Synaptic Plasticity at Cerebellar Parallel Fiber Synapses

2011 ◽  
Vol 105 (2) ◽  
pp. 958-963 ◽  
Author(s):  
Megan R. Carey ◽  
Michael H. Myoga ◽  
Kimberly R. McDaniels ◽  
Giovanni Marsicano ◽  
Beat Lutz ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Purkinje Cells ◽  
Cannabinoid Receptors ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Inhibitory Interneuron ◽  
Parallel Fiber ◽  
Short Term ◽  
Short Term Plasticity

Endocannabinoids are potent regulators of synaptic strength. They are generally thought to modify neurotransmitter release through retrograde activation of presynaptic type 1 cannabinoid receptors (CB1Rs). In the cerebellar cortex, CB1Rs regulate several forms of synaptic plasticity at synapses onto Purkinje cells, including presynaptically expressed short-term plasticity and, somewhat paradoxically, a postsynaptic form of long-term depression (LTD). Here we have generated mice in which CB1Rs were selectively eliminated from cerebellar granule cells, whose axons form parallel fibers. We find that in these mice, endocannabinoid-dependent short-term plasticity is eliminated at parallel fiber, but not inhibitory interneuron, synapses onto Purkinje cells. Further, parallel fiber LTD is not observed in these mice, indicating that presynaptic CB1Rs regulate long-term plasticity at this synapse.

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

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.

Synaptic Dynamics on Different Time Scales in a Parallel Fiber Feedback Pathway of the Weakly Electric Fish

2004 ◽  
Vol 91 (2) ◽  
pp. 1064-1070 ◽  
Author(s):  
John E. Lewis ◽  
Leonard Maler
Keyword(s):  
Time Scales ◽  
Electric Fish ◽  
Parallel Fiber ◽  
Weakly Electric Fish ◽  
Short Term ◽  
Parallel Fibers ◽  
Short Term Plasticity ◽  
Synaptic Dynamics ◽  
Weakly Electric

Synaptic dynamics comprise a variety of interacting processes acting on a wide range of time scales. This enables a synapse to perform a large array of computations, from temporal and spatial filtering to associative learning. In this study, we describe how changing synaptic gain via long-term plasticity can act to shape the temporal filtering of a synapse through modulation of short-term plasticity. In the weakly electric fish, parallel fibers from cerebellar granule cells provide massive feedback inputs to the pyramidal neurons of the electrosensory lateral line lobe. We demonstrate a long-term synaptic enhancement (LTE) of these synapses that is biochemically similar to the presynaptic long-term potentiation expressed by parallel fibers in the mammalian cerebellum. Using a novel stimulation protocol and a simple modeling paradigm, we then quantify the changes in short-term plasticity during the induction of LTE and show that these changes can be explained by gradual changes in only one model parameter, that which is associated with the baseline probability of transmitter release. These changes lead to a shift in the spike frequency preference of the synapse, suggesting that long-term plasticity is not only involved in controlling the gain of the parallel fiber synapse, but also provides a means of controlling synaptic filtering over multiple time scales.

scholarly journals Enhancing Short-Term Plasticity by Inserting a Thin TiO2 Layer in WOx-Based Resistive Switching Memory

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 908 ◽  
Author(s):  
Hyojong Cho ◽  
Sungjun Kim
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Short Term Memory ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
X Ray ◽  
Short Term Plasticity ◽  
Good Retention

In this work, we emulate biological synaptic properties such as long-term plasticity (LTP) and short-term plasticity (STP) in an artificial synaptic device with a TiN/TiO2/WOx/Pt structure. The graded WOx layer with oxygen vacancies is confirmed via X-ray photoelectron spectroscopy (XPS) analysis. The control TiN/WOx/Pt device shows filamentary switching with abrupt set and gradual reset processes in DC sweep mode. The TiN/WOx/Pt device is vulnerable to set stuck because of negative set behavior, as verified by both DC sweep and pulse modes. The TiN/WOx/Pt device has good retention and can mimic long-term memory (LTM), including potentiation and depression, given repeated pulses. On the other hand, TiN/TiO2/WOx/Pt devices show non-filamentary type switching that is suitable for fine conductance modulation. Potentiation and depression are demonstrated in the TiN/TiO2 (2 nm)/WOx/Pt device with moderate conductance decay by application of identical repeated pulses. Short-term memory (STM) is demonstrated by varying the interval time of pulse inputs for the TiN/TiO2 (6 nm)/WOx/Pt device with a quick decay in conductance.

Long-term depression of Aplysia sensorimotor synapses in cell culture: inductive role of a rise in postsynaptic calcium

1996 ◽  
Vol 76 (3) ◽  
pp. 2111-2114 ◽  
Author(s):  
X. Y. Lin ◽  
D. L. Glanzman
Keyword(s):  
Cell Culture ◽  
Synaptic Plasticity ◽  
Sensory Neurons ◽  
Tetraacetic Acid ◽  
Short Term ◽  
Long Term Depression ◽  
Central Synapses ◽  
Postsynaptic Calcium

1. Activation of sensory neurons at 2 Hz for 15 min induces long-term depression (LTD) of isolated Aplysia sensorimotor synapses in cell culture. 2. Prior infusion of the Ca2+ chelator 1,2-bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA) into the postsynaptic motor neuron blocks the induction of LTD, but not short-term synaptic depression. 3. Invertebrate central synapses possess the capacity for LTD. This form of long-term synaptic plasticity may play an important role in learning in Aplysia.

scholarly journals Asymmetries in long-term and short-term plasticity at thalamic and cortical inputs to the amygdalain vivo

2010 ◽  
Vol 31 (2) ◽  
pp. 250-262 ◽  
Author(s):  
Torfi Sigurðsson ◽  
Christopher K. Cain ◽  
Valérie Doyère ◽  
Joseph E. LeDoux
Keyword(s):  
Short Term ◽  
Short Term Plasticity ◽  
Cortical Inputs

scholarly journals A model of order-selectivity based on dynamic changes in the balance of excitation and inhibition produced by short-term synaptic plasticity

2015 ◽  
Vol 113 (2) ◽  
pp. 509-523 ◽  
Author(s):  
Vishwa Goudar ◽  
Dean V. Buonomano
Keyword(s):  
Synaptic Plasticity ◽  
Computational Models ◽  
Experimental Studies ◽  
Inhibitory Synapses ◽  
Speech Discrimination ◽  
Short Term ◽  
Dynamic Changes ◽  
Short Term Plasticity ◽  
Underlying Mechanisms ◽  
Parametric Analyses

Determining the order of sensory events separated by a few hundred milliseconds is critical to many forms of sensory processing, including vocalization and speech discrimination. Although many experimental studies have recorded from auditory order-sensitive and order-selective neurons, the underlying mechanisms are poorly understood. Here we demonstrate that universal properties of cortical synapses—short-term synaptic plasticity of excitatory and inhibitory synapses—are well suited for the generation of order-selective neural responses. Using computational models of canonical disynaptic circuits, we show that the dynamic changes in the balance of excitation and inhibition imposed by short-term plasticity lead to the generation of order-selective responses. Parametric analyses predict that among the forms of short-term plasticity expressed at excitatory-to-excitatory, excitatory-to-inhibitory, and inhibitory-to-excitatory synapses, the single most important contributor to order-selectivity is the paired-pulse depression of inhibitory postsynaptic potentials (IPSPs). A topographic model of the auditory cortex that incorporates short-term plasticity accounts for both context-dependent suppression and enhancement in response to paired tones. Together these results provide a framework to account for an important computational problem based on ubiquitous synaptic properties that did not yet have a clearly established computational function. Additionally, these studies suggest that disynaptic circuits represent a fundamental computational unit that is capable of processing both spatial and temporal information.

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