Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Astrocytes and synaptic plasticity

Astrocytes and synaptic plasticity

October 13, 2008

By mopping up excess neurotrophic factor from neuronal synapses, astrocytes may finely tune synaptic transmission to affect processes such as learning and memory, say Bergami et al.

The major cellular events of learning and memory are long-term potentiation (LTP) and long-term depression (LTD), both of which affect neurons' ability to communicate with one another. Neurons that have undergone LTP display a stronger electrical response to the same level of a stimulus, whereas neurons that have gone through LTD display a weaker response. These changes are thought to result from modifications of the neuronal synapses, such as alterations in the density of postsynaptic receptors, or downstream signaling events.




Secretion of the neurotrophic factor BDNF (brain-derived neurotrophic factor) has been implicated in long-term synaptic modification, and the function of BDNF on synaptic strength depends on its particular form: in its pro-BDNF form it is believed to promote LTD, and in its mature form it prompts LTP. Neurons were thought to secrete pro-BDNF, which then matured into BDNF in the synaptic space. However, a recent study suggests that only mature BDNF is secreted, pro-BDNF being processed intracellularly.

To get to the bottom of things, Bergami et al. investigated the fate of both forms after LTP induction in brain slices from the rat cortex. By fluorescent immunohistochemistry they showed that that neurons indeed secrete both mature and pro-BDNF, but that a large amount of the pro-BDNF is immediately taken up by astrocytes.

Astrocytes, previously thought to be unimportant in neuronal transmission, have recently been implicated in long-term modulation of neuronal synapses. For example, they release the neurotransmitter glutamate into the synapse prompting LTP. By specifically mopping up pro-BDNF, astrocytes seem to have another means to assist in LTP. However, while it's likely that most pro-BDNF gets degraded inside astrocytes, say the authors, some gets recycled and re-released, suggesting that astrocytes in fact fine-tune synaptic plasticity.

Rockefeller University Press



Related Neuronal Synapses Current Events and Neuronal Synapses News Articles
Astrocytes and synaptic plasticity
By mopping up excess neurotrophic factor from neuronal synapses, astrocytes may finely tune synaptic transmission to affect processes such as learning and memory, say Bergami et al.

New Brandeis research sheds light on memory by erasing it
For years, scientists have studied the molecular basis of memory storage, trying to find the molecules that store memory, just as DNA stores genetic memory.

Brains response to visual stimuli helps us to focus on what we should see, rather than all there is to see
Delving ever deeper into the intricate architecture of the brain, researchers at The Salk Institute have now described how two different types of nerve cells, called neurons, work together in tiny sub-networks to pass on just the right amount and the right kind of sensory information.

Hebrew University, German And British Researchers Develop Means To Help Post-Traumatic Stress Sufferers
Try as we may to suppress memories of highly stressful experiences, they nevertheless come back to bother us - even causing attacks of intense fear or other undesirable behavioral impairments. Now a group of German, Israeli and British scientists and students have found that a gene-based approach offers promise for development of a treatment that can suppress these reactions while not impairing memory itself. In an article appearing as the cover story in the current issue of Molecular Psychiatry, a team of researchers from the Silberman Institute of Life Sciences at the Hebrew University of Jerusalem and the Max Planck Institute for Experimental Medicine in Goettingen, Germany, describe the
More Neuronal Synapses Current Events and Neuronal Synapses News Articles
Methods in Neuronal Modeling: From Synapses to Networks
by Christof Koch, Idan Segev

Strengthening your synapses, keys to learning: nurturing these critical neuronal connections can protect your memory and help you stay mentally alert.: An article from: Mind, Mood & Memory
by Gale Reference Team

This digital document is an article from Mind, Mood & Memory, published by Thomson Gale on February 1, 2007. The length of the article is 1333 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.Citation DetailsTitle:...

METHODS IN NEURONAL MODELING, FROM SYNAPSES TO NETWORKS; PART OF SERIES, COMPUTATIONAL NEUROSCIENCE
by Christof and Idan Segev, Editors Koch

METHODS IN NEURONAL MODELING: FROM SYNAPSES TO NETWORKS. Computational Neuroscience Series.
by Christof & Idan Segev (editors). Koch

Methods in Neuronal Modeling: From Synapses to Networks
by Christof Koch

Synapse: Function, Plasticity, and Neurotrophism
by Motoy Kuno

The synapse not only provides a bridge from one nerve cell to the next; its function can be modified by experience, making it important for learning and memory, and it plays an important role in the growth and development of the nervous system. This is a central topic in the study of neuroscience on which molecular biology has had a major impact. Professor Kuno has written the first accessible...



Communication in Plants: Neuronal Aspects of Plant Life

Plant neurobiology is a newly emerging field of plant sciences. It covers signalling and communication at all levels of biological organization – from molecules up to ecological communities. In this book, plants are presented as intelligent and social organisms with complex forms of communication and information processing. Authors from diverse backgrounds such as molecular and cellular...

Synaptic transmission and neuronal interaction (Society of General Physiologists series, v. 28)
by Michael V. L Bennett

Neuronal Communications (Physiological Society Study Guides, No 4)



Analysis of Neuronal Microcircuits and Synaptic Interactions (Handbook of Chemical Neuroanatomy)
by T. Hokfelt, F.G. Wouterlood, A.N. Van den Pol

Hardbound. This volume of the Handbook of Chemical Neuroanatomy describes the techniques used to study the connectivity of chemically defined neurons at the cellular level. Among areas dealt with are the most recent developments in light microscopy and electron microscopy, and the applications to specific subjects of chosen combinations of techniques to demonstrate how elegantly and powerfully...

© 2009 BrightSurf.com