>>> context weblog
sampling new cultural context
| home | site map | about context | donate | lang >>> español - català |
wednesday :: february 19, 2003
   
 
synapses: plasticity and stability

A Duke University Medical Center neurobiologist has identified key mechanisms by which the intricate 'protein machines' that govern the strength of connections among neurons build and remodel themselves to adjust those connections.

Such remodeling of the connections, called synapses, is central to the establishment of brain pathways during learning and memory, said the scientists. Also, malfunction of the synaptic machinery might well play a fundamental role in the pathology of neurodegenerative disorders including Parkinson's and Alzheimer's diseases.

Neurobiologist Michael Ehlers reported extensive experiments revealing the function of a structure known as the 'post-synaptic density' (PSD). The PSD is so named because it is a thickening of the membrane at the connection point between neurons, where one neuron receives biochemical signals called neurotransmitters from its neighbor. Such neurotransmitters are themeans by which one neuron triggers the receiving neuron to launch a nerve impulse. Ehlers explored the gain or loss of a multitude of known PSD proteins. "I found that neurons in these cultures replace the content of this signaling machine multiple times a day," said Ehlers. "And if this recapitulates what's going in the mammalian brain, this means that synapses are completely turning over all of their constituents multiple times a day ­ a stunning finding."

Neuroscientists have long been intrigued in how the brain changes with learning and experience, a phenomenon called plasticity. Yet, as Ehlers points out, "perhaps we need to think more closely about how connections in the brain remain stable in the face of such incredible ongoing turnover." >from *New insights into how the nerve connection machinery remodels itself*, february 9, 2003

related context
>
synaptic plasticity: how experiences rewire the brain. january 23, 2003

imago
>
protein machine

| permaLink






> context weblog archive
december 2006
november 2006
october 2006
september 2006
august 2006
july 2006
june 2006
may 2006
april 2006
march 2006
february 2006
january 2006
december 2005
november 2005
october 2005
september 2005
august 2005
july 2005
june 2005
may 2005
april 2005
march 2005
february 2005
january 2005
december 2004
november 2004
october 2004
september 2004
august 2004
july 2004
june 2004
may 2004
april 2004
march 2004
february 2004
january 2004
december 2003
november 2003
october 2003
june 2003
may 2003
april 2003
march 2003
february 2003
january 2003
december 2002
november 2002
october 2002
july 2002
june 2002
may 2002
april 2002
march 2002
february 2002
january 2002
countdown 2002
december 2001
november 2001
october 2001
september 2001
august 2001

more news in
> sitemap

Google


context archives all www
   "active, informed citizen participation is the key to shaping the network society. a new 'public sphere' is required." seattle statement
| home | site map | about context | donate | lang >>> español - català |
03 http://straddle3.net/context/03/en/2003_02_19.html