Show Advanced Search

REFINE YOUR SEARCH:

Containing Text
- - -
+
Filter by author or institution
GO
Filter by publication date
From:
October, 2006
Until:
Today
Filter by journal section

Filter by science education

 
 
Long-Term Potentiation: A persistent increase in synaptic efficacy, usually induced by appropriate activation of the same synapses. The phenomenological properties of long-term potentiation suggest that it may be a cellular mechanism of learning and memory.

Long-term Potentiation

JoVE 10846

Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory. LTP can occur when presynaptic neurons repeatedly fire and stimulate the postsynaptic neuron. This is called Hebbian LTP since it follows from Donald Hebb’s 1949 postulate that “neurons that fire together wire together.” The repeated stimulation from presynaptic neurons induces changes in the type and number of ion channels in the postsynaptic membrane. Two types of postsynaptic receptors of the excitatory neurotransmitter glutamate are involved in LTP: 1) N-methyl-D-aspartate or NMDA receptors and 2) α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid or AMPA receptors. Although NMDA receptors open upon glutamate binding, their pore is usually blocked by magnesium ions that prevent other positively charged ions from entering the neuron. However, glutamate released from presynaptic neurons can bind to postsynaptic AMPA receptors, causing an influx of sodium ions that results

 Core: Nervous System

Long-term Depression

JoVE 10847

Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTD is the process of synaptic weakening that occurs over time between pre and postsynaptic neuronal connections. The synaptic weakening of LTD works in opposition to synaptic strengthening by long-term potentiation (LTP) and together are the main mechanisms that underlie learning and memory. If over time, all synapses are maximally strengthened through LTP or some other mechanism, the brain would plateau in efficiency making learning and forming new memories difficult. LTD is a way to prune weaker synapses thereby freeing up resources and putting flexibility back into the central nervous system. One mechanism by which LTD occurs depends on the number of calcium ions in the postsynaptic neuron after presynaptic stimulation. Infrequent or low levels of presynaptic stimulation lead to low calcium ion influx and consequently, low calcium ion concentration in the postsynaptic neuron. The low calcium ion concentration initiates a signaling cascade that culminates in the endocytosis or removal of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptors from the plasma membrane. As a result, the postsynaptic response to the same sporadic presynaptic stimulation is further wea

 Core: Nervous System

An Introduction to Cellular and Molecular Neuroscience

JoVE 5213

Cellular and molecular neuroscience is one of the newest and fastest growing subdisciplines in neuroscience. By investigating the influences of genes, signaling molecules, and cellular morphology, researchers in this field uncover crucial insights into normal brain development and function, as well as the root causes of many pathological conditions.


 Neuroscience

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism

1Department of Psychology, University of Montréal, 2Montreal Neurological Institute, McGill University, 3Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota

JoVE 51631

 Neuroscience

Stereotaxic Surgery for Excitotoxic Lesion of Specific Brain Areas in the Adult Rat

1Helen Wills Neuroscience Institute, University of California Berkeley, 2Office of Laboratory Animal Care, University of California Berkeley, 3McGovern Institute for Brain Research & The Department of Brain and Cognitive Science, Massachusetts Institute of Technology, 4Integrative Biology Department, University of California Berkeley

JoVE 4079

 Neuroscience

High Resolution Quantitative Synaptic Proteome Profiling of Mouse Brain Regions After Auditory Discrimination Learning

1Leibniz Institute for Neurobiology (LIN), 2Institute of Experimental Internal Medicine, Medical School, Otto von Guericke University Magdeburg, 3Institute of Pharmacology and Toxicology, Medical School, Otto von Guericke University

JoVE 54992

 Neuroscience

A Novel In Vitro Model of Blast Traumatic Brain Injury

1Anaesthetics, Pain Medicine and Intensive Care Section, Department of Surgery and Cancer, Imperial College London, 2Royal British Legion Centre for Blast Injury Studies, Department of Bioengineering, Imperial College London, 3Department of Bioengineering, Imperial College London, 4Department of Life Sciences, Imperial College London, 5Department of Anaesthetics, Royal Berkshire Hospital NHS Foundation Trust, 6Royal Centre for Defence Medicine, Medical Directorate Joint Force Command

JoVE 58400

 Neuroscience

Brain State-dependent Brain Stimulation with Real-time Electroencephalography-Triggered Transcranial Magnetic Stimulation

1Department of Neurology & Stroke, University of Tübingen, 2Hertie Institute for Clinical Brain Research, University of Tübingen, 3Department of Neuroscience and Biomedical Engineering, Aalto University

JoVE 59711

 Behavior

Analysis of Learning and Memory Ability in an Alzheimer's Disease Mouse Model using the Morris Water Maze

1School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, 2Guang'anmen Hospital of China Academy of Chinese Medical Science, 3The Third Affiliated Hospital of Beijng University of Chinese Medicine, 4School of Nursing, Beijing University of Chinese Medicine

Video Coming Soon

JoVE 60055

 JoVE In-Press

A New Method for Inducing a Depression-Like Behavior in Rats

1Department of Emergent Medicine, Soroka University Medical Center, Ben-Gurion University of the Negev, 2Division of Anesthesiology and Critical Care, Soroka Medical Center, Ben-Gurion University of the Negev, 3Department of Biophysics and Biochemistry, Oles' Honchar Dnipro National University

JoVE 57137

 Behavior
12
More Results...