Long-term potentiation of synaptic transmission in the hippocampus is the primary experimental model for investigating the synaptic basis of learning and memory in vertebrates. The best understood form of long-term potentiation is induced by the activation of the N-methyl-D-aspartate receptor complex. This subtype of glutamate receptor endows long-term potentiation with Hebbian characteristics, and allows electrical events at the postsynaptic membrane to be transduced into chemical signals which, in turn, are thought to activate both pre- and postsynaptic mechanisms to generate a persistent increase in synaptic strength.

A synaptic model of memory: long-term potentiation in the hippocampus

The field of neuroscience has, after a long period of looking the other way, again embraced emotion as an important research area. Much of the progress has come from studies of fear, and especially fear conditioning. This work has pin- pointed the amygdala as an important component of the system involved in the acqui- sition, storage, and expression of fear memory and has elucidated in detail how stimuli enter, travel through, and exit the amygdala. Some progress has also been made in understanding the cellular and molecular mechanisms that underlie fear conditioning, and recent studies have also shown that the findings from experimental animals apply to the human brain. It is important to remember why this work on emotion succeeded where past efforts failed. It focused on a psychologically well-defined aspect of emo- tion, avoided vague and poorly defined concepts such as "affect," "hedonic tone," or "emotional feelings," and used a simple and straightforward experimental approach. With so much research being done in this area today, it is important that the mistakes of the past not be made again. It is also time to expand from this foundation into broader aspects of mind and behavior

http://gruberpeplab.com/3131/LeDoux_2000_Emotioncircuitbrain.pdf

Emotion Circuits in the Brain

Revealing how smart design is the new competitive frontier, this innovative book is a powerful primer on how--and why--some products satisfy customers while others only frustrate them.

https://www.cc.gatech.edu/~stasko/6750/Talks/08-doet.pdf

Design of Everyday Things

1. Introduction 2. The emergence of learning activity as a historical form of human learning 3. The zone of proximal development as the basic category of expansive research 4. The instruments of expansion 5. Toward an expansive methodology 6. Epilogue.

Learning by expanding: An activity-theoretical approach to developmental research

http://download.neurosky.com/docs/papers/bcq/Klimesch_1999_EEG_alpha_and_theta_oscillations_reflect_cognitive_and_memory_performance.pdf

EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis

How the brain codes, stores, and retrieves memories is among the most important and baffling questions in science. The uniqueness of each human being is due largely to the memory store—the biological residue of memory from a lifetime of experience. The cellular basis of this ability to learn can be traced to simpler organisms. In the past generation, understanding of the biological basis of learning and memory has undergone a revolution. It is clear that various forms and aspects of learning and memory involve particular systems, networks, and circuits in the brain, and it now appears possible to identify these circuits, localize the sites of memory storage, and analyze the cellular and molecular mechanisms of memory.

Learning and memory

Long-term potentiation (LTP) is an experience-dependent form of neural plasticity believed to involve mechanisms that underlie memory formation. LTP has been studied most extensively in the hippocampus, but the relation between hippocampal LTP and memory has been difficult to establish. Here we explore the relation between LTP and memory in fear conditioning, an amygdala-dependent form of learning in which an innocuous conditioned stimulus (CS) elicits fear responses after being associatively paired with an aversive unconditioned stimulus (US). We have previously shown that LTP induction in pathways that transmit auditory CS information to the lateral nucleus of the amygdala (LA) increases auditory-evoked field potentials in this nucleus. Now we show that fear conditioning alters auditory CS-evoked responses in LA in the same way as LTP induction. The changes parallel the acquisition of CS-elicited fear behaviour, are enduring, and do not occur if the CS and US remain unpaired. LTP-like associative processes thus occur during fear conditioning, and these may underlie the long-term associative plasticity that constitutes memory of the conditioning experience.

Fear conditioning induces associative long-term potentiation in the amygdala

Stable hippocampal long-term potentiation elicited by 'theta' pattern stimulation.

A benzamide drug that crosses the blood-brain barrier and facilitates DL-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-mediated synaptic responses was tested for its effects on memory in three behavioral tasks. The compound reversibly increased the amplitude and prolonged the duration of field excitatory postsynaptic potentials in hippocampal slices and produced comparable effects in the dentgate gyrus in situ after intraperitoneal injections. Rats injected with the drug 30 min prior to being given a suboptimal number of training trials in a two-odor discrimination task were more likely than controls to select the correct odor in a retention test carried out 96 hr later. Evidence for improved memory was also obtained in a water maze task in which rats were given only four trials to find a submerged platform in the presence of spatial cues; animals injected with the drug 30 min before the training session were significantly faster than vehicle-injected controls in returning to the platform location when tested 24 hr after training. Finally, the drug produced positive effects in a radial maze test of short-term memory. Well trained rats were allowed to retrieve rewards from four arms of an eight-arm maze and then tested for reentry errors 8 hr later. The number of such errors was substantially reduced on days in which the animals were injected with the drug before initial learning. These results indicate that a drug that facilitates glutamatergic transmission enhances the encoding of memory across tasks involving different sensory cues and performance requirements. This may reflect an action on the cellular mechanisms responsible for producing synaptic changes since facilitation of AMPA receptors promotes the induction of the long-term potentiation effect.

/pdf/facilitation-of-glutamate-receptors-enhances-memory-2zk0gtidhv.pdf

Ursula Staubli

Papers

Learning and memory

Fear conditioning induces associative long-term potentiation in the amygdala

Stable hippocampal long-term potentiation elicited by 'theta' pattern stimulation.

Facilitation of glutamate receptors enhances memory.

Stable depression of potentiated synaptic responses in the hippocampus with 1-5 Hz stimulation.