scholarly journals Modelling thalamocortical circuitry shows visually induced LTP changes laminar connectivity in human visual cortex

2020 ◽  
Author(s):  
Rachael L. Sumner ◽  
Meg J. Spriggs ◽  
Alexander D. Shaw
Keyword(s):  
Visual Cortex ◽  
Computational Model ◽  
Evoked Potential ◽  
Long Term Potentiation ◽  
The State ◽  
Clinical Neuroscience ◽  
Non Invasive ◽  
Term Potentiation ◽  
The Brain

AbstractNeuroplasticity is essential to learning and memory in the brain; it has therefore also been implicated in numerous neurological and psychiatric disorders, making measuring the state of neuroplasticity of foremost importance to clinical neuroscience. Long-term potentiation (LTP) is a key mechanism of neuroplasticity and has been studied extensively, and invasively in non-human animals. Translation to human application largely relies on the validation of non-invasive measures of LTP. The current study provides validation for the use of a thalamocortical computational model of visual cortex for investigating and replicating interlaminar connectivity changes using non-invasive EEG recording of humans, and a commonly used visual sensory LTP paradigm. The model demonstrated remarkable accuracy recapitulating post-tetanus changes including increased excitatory connectivity from thalamus to layer IV and from layer IV to II/III. The findings also further validate visual sensory induced LTP and evoked potential modulation for measuring of the state of LTP in cortex.

scholarly journals Modelling thalamocortical circuitry shows that visually induced LTP changes laminar connectivity in human visual cortex

2021 ◽  
Vol 17 (1) ◽  
pp. e1008414
Author(s):  
Rachael L. Sumner ◽  
Meg J. Spriggs ◽  
Alexander D. Shaw
Keyword(s):  
Visual Cortex ◽  
Long Term Potentiation ◽  
Psychiatric Disease ◽  
Clinical Neuroscience ◽  
Non Invasive ◽  
Causal Modelling ◽  
Term Potentiation ◽  
Eeg Data ◽  
The Brain

Neuroplasticity is essential to learning and memory in the brain; it has therefore also been implicated in numerous neurological and psychiatric disorders, making measuring the state of neuroplasticity of foremost importance to clinical neuroscience. Long-term potentiation (LTP) is a key mechanism of neuroplasticity and has been studied extensively, and invasively in non-human animals. Translation to human application largely relies on the validation of non-invasive measures of LTP. The current study presents a generative thalamocortical computational model of visual cortex for investigating and replicating interlaminar connectivity changes using non-invasive EEG recording of humans. The model is combined with a commonly used visual sensory LTP paradigm and fit to the empirical EEG data using dynamic causal modelling. The thalamocortical model demonstrated remarkable accuracy recapitulating post-tetanus changes seen in invasive research, including increased excitatory connectivity from thalamus to layer IV and from layer IV to II/III, established major sites of LTP in visual cortex. These findings provide justification for the implementation of the presented thalamocortical model for ERP research, including to provide increased detail on the nature of changes that underlie LTP induced in visual cortex. Future applications include translating rodent findings to non-invasive research in humans concerning deficits to LTP that may underlie neurological and psychiatric disease.

Enhancement of neuroplasticity by cortical stimulation

2020 ◽  
pp. 199-220
Author(s):  
Orlando B.C. Swayne ◽  
John C. Rothwell
Keyword(s):  
Clinical Trials ◽  
Neurological Disease ◽  
Magnetic Stimulation ◽  
Long Term Potentiation ◽  
Response To Therapy ◽  
Non Invasive ◽  
Term Potentiation ◽  
The Face ◽  
The Brain

Non-invasive brain stimulation methods such as transcranial magnetic stimulation and transcranial direct current stimulation allow us to interact directly with activity in neural circuits in the brain. Work has shown that these methods can also lead to changes in the effectiveness of synaptic connections, probably through mechanisms related to long-term potentiation/depression as described in animal preparations. Similar processes of synaptic plasticity are involved in many neurological rehabilitation techniques involve learning how to optimize performance in the face of neurological disease or injury. Thus combining non-invasive stimulation with rehabilitation may therefore be able to enhance plasticity and speed the response to therapy. We describe the techniques involved and summarize some of the recent clinical trials that have been conducted using this approach.

Neurotrophins and Proneurotrophins: Focus on Synaptic Activity and Plasticity in the Brain

2017 ◽  
Vol 23 (6) ◽  
pp. 587-604 ◽  
Author(s):  
Julien Gibon ◽  
Philip A. Barker
Keyword(s):  
Long Term Potentiation ◽  
Synaptic Activity ◽  
Cellular Processes ◽  
Term Potentiation ◽  
Neurotrophin 3 ◽  
New Findings ◽  
The Central Nervous System ◽  
The Brain

Neurotrophins have been intensively studied and have multiple roles in the brain. Neurotrophins are first synthetized as proneurotrophins and then cleaved intracellularly and extracellularly. Increasing evidences demonstrate that proneurotrophins and mature neurotrophins exerts opposing role in the central nervous system. In the present review, we explore the role of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT3), and neurotrophin 4 (NT4) and their respective proform in cellular processes related to learning and memory. We focused on their roles in synaptic activity and plasticity in the brain with an emphasis on long-term potentiation, long-term depression, and basal synaptic transmission in the hippocampus and the temporal lobe area. We also discuss new findings on the role of the Val66Met polymorphism on the BDNF propeptide on synaptic activity.

T161. Long-Term Potentiation-Like Visual Evoked Potential Plasticity in a Large Sample of Healthy Volunteers: Effect Sizes and Response Rates

2018 ◽  
Vol 83 (9) ◽  
pp. S190-S191
Author(s):  
Mathias Valstad ◽  
Torgeir Moberget ◽  
Lars T. Westlye ◽  
Daniël T.H. Roelfs ◽  
Knut Skaug ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Response Rates ◽  
Long Term Potentiation ◽  
Effect Sizes ◽  
Large Sample ◽  
Term Potentiation ◽  
Visual Evoked

Priming-Induced Shift in Synaptic Plasticity in the Rat Hippocampus

1999 ◽  
Vol 82 (4) ◽  
pp. 2024-2028 ◽  
Author(s):  
Hongyan Wang ◽  
John J. Wagner
Keyword(s):  
Synaptic Plasticity ◽  
Hippocampal Slices ◽  
Long Term Potentiation ◽  
Crossover Point ◽  
Term Potentiation ◽  
Before And After ◽  
History Of ◽  
The Brain ◽  
Dependent Mechanism

The activity history of a given neuron has been suggested to influence its future responses to synaptic input in one prominent model of experience-dependent synaptic plasticity proposed by Bienenstock, Cooper, and Munro (BCM theory). Because plasticity of synaptic plasticity (i.e., metaplasticity) is similar in concept to aspects of the BCM proposal, we have tested the possibility that a form of metaplasticity induced by a priming stimulation protocol might exhibit BCM-like characteristics. CA1 field excitatory postsynaptic potentials (EPSPs) obtained from rat hippocampal slices were used to monitor synaptic responses before and after conditioning stimuli (3–100 Hz) of the Schaffer collateral inputs. A substantial rightward shift (>5-fold) in the frequency threshold between long-term depression (LTD) and long-term potentiation (LTP) was observed <1 h after priming. This change in the LTD/P crossover point occurred at both primed and unprimed synaptic pathways. These results provide new support for the existence of a rapid, heterosynaptic, experience-dependent mechanism that is capable of modifying the synaptic plasticity phenomena that are commonly proposed to be important for developmental and learning/memory processes in the brain.

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