Activity-dependent presynaptic facilitation: An associative mechanism inAplysia

1985 ◽  
Vol 5 (1-2) ◽  
pp. 123-145 ◽  
Author(s):  
Thomas W. Abrams
Keyword(s):  
Associative Mechanism ◽  
Activity Dependent ◽  
Presynaptic Facilitation

scholarly journals Activity-dependent enhancement of presynaptic facilitation provides a cellular mechanism for the temporal specificity of classical conditioning in Aplysia.

1994 ◽  
Vol 1 (4) ◽  
pp. 243-257
Author(s):  
G A Clark ◽  
R D Hawkins ◽  
E R Kandel
Keyword(s):  
Action Potential ◽  
Classical Conditioning ◽  
Sensory Neurons ◽  
Cell Activity ◽  
Critical Time ◽  
Ionic Currents ◽  
Temporal Specificity ◽  
The Us ◽  
Activity Dependent ◽  
Presynaptic Facilitation

A hallmark of many forms of classical conditioning is a precise temporal specificity: Learning is optimal when the conditioned stimulus (CS) slightly precedes the unconditioned stimulus (US), but the learning is degraded at longer or backward intervals, consistent with the notion that conditioning involves learning about predictive relationships in the environment. To further examine the cellular mechanisms contributing to the temporal specificity of classical conditioning of the siphon-withdrawal response in Aplysia, we paired action potential activity in siphon sensory neurons (the neural CS) with tail nerve shock (the US) at three critical time points. We found that CS-US pairings at short (0.5 sec) forward intervals produced greater synaptic facilitation at sensorimotor connections than did either 0.5-sec backward pairings or longer (5 sec) forward pairings, as reflected in a differential increase in both the amplitude and rate of rise of the synaptic potential. In the same preparations, forward pairings also differentially reduced the sensory neuron afterhyperpolarization relative to backward pairings, suggesting that changes in synaptic efficacy were accompanied by temporally specific changes in ionic currents in the sensory neurons. Additional experiments demonstrated that short forward pairings of sensory cell activity and restricted applications of the neuromodulatory transmitter serotonin (normally released by the US) differentially enhanced action potential broadening in siphon sensory neurons, relative to backward pairings. Taken together, these results suggest that temporally specific synaptic enhancement engages both spike-width-dependent and spike-width-independent facilitatory processes and that activity-dependent enhancement of presynaptic facilitation may contribute to both the CS-US sequence and proximity requirements of conditioning.

scholarly journals Activity-Dependent Presynaptic Facilitation and Hebbian LTP Are Both Required and Interact during Classical Conditioning in Aplysia

Neuron ◽  
2003 ◽  
Vol 37 (1) ◽  
pp. 135-147 ◽  
Author(s):  
Igor Antonov ◽  
Irina Antonova ◽  
Eric R. Kandel ◽  
Robert D. Hawkins
Keyword(s):  
Classical Conditioning ◽  
Activity Dependent ◽  
Presynaptic Facilitation

Malfunctional Reorganization in the Developing Limbo-Prefrontal System in Animals: Implications for Human Psychoses?

2001 ◽  
Vol 12 (1) ◽  
pp. 8-14
Author(s):  
Gertraud Teuchert-Noodt ◽  
Ralf R. Dawirs
Keyword(s):  
Prefrontal Cortex ◽  
Mental Disorders ◽  
Dentate Gyrus ◽  
Cognitive Functions ◽  
Experimental Approach ◽  
Regulatory Mechanisms ◽  
Hippocampal Dentate Gyrus ◽  
Non Invasive ◽  
Invasive Method ◽  
Activity Dependent

Abstract: Neuroplasticity research in connection with mental disorders has recently bridged the gap between basic neurobiology and applied neuropsychology. A non-invasive method in the gerbil (Meriones unguiculus) - the restricted versus enriched breading and the systemically applied single methamphetamine dose - offers an experimental approach to investigate psychoses. Acts of intervening affirm an activity dependent malfunctional reorganization in the prefrontal cortex and in the hippocampal dentate gyrus and reveal the dopamine position as being critical for the disruption of interactions between the areas concerned. From the extent of plasticity effects the probability and risk of psycho-cognitive development may be derived. Advance may be expected from insights into regulatory mechanisms of neurogenesis in the hippocampal dentate gyrus which is obviously to meet the necessary requirements to promote psycho-cognitive functions/malfunctions via the limbo-prefrontal circuit.

Compartment-resolved imaging of activity dependent dynamics of cortical blood volume and oximetry

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S681-S681 ◽  
Author(s):  
Amiram Grinvald ◽  
Rina Hildesheim ◽  
Ivo Vanzetta
Keyword(s):  
Blood Volume ◽  
Activity Dependent

A Matter of Perspective: How adults represent causal launching sequences

2020 ◽  
Author(s):  
Deon T. Benton ◽  
David H. Rakison
Keyword(s):  
Specific Mechanism ◽  
Associative Mechanism ◽  
Low Level ◽  
Domain Specific ◽  
The World ◽  
Modular Domain ◽  
Stimulus Features

The ability to reason about causal events in the world is fundamental to cognition. Despite the importance of this ability, little is known about how adults represent causal events, what structure or form those representations take, and what the mechanism is that underpins such representations. We report four experiments with adults that examine the perceptual basis on which adults represent four-object launching sequences (Experiments 1 and 2), whether adults representations reflect sensitivity to the causal, perceptual, or causal and perceptual relation among the objects that comprise such sequences (Experiment 3), and whether such representations extend beyond spatiotemporal contiguity to include other low-level stimulus features such as an object’s shape and color (Experiment 4). Based on these results of the four experiments, we argue that a domain-general associative mechanism, rather a modular, domain-specific, mechanism subserves adults’ representations of four-object launching sequences.

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