Article] Good news for prions?



R

Robert Karl Sto

Guest
Good news for prions?

Mad cow and memory: Prion-like proteins proposed to regulate neuronal plasticity By Brendan A Maher

Since their discovery in 1982, prions have been mostly associated with deadly and devastating
neurodegenerative disorders-notably variant Creutzfeld-Jakob disease and bovine spongiform
encephalopathy. Nevertheless, some maintain that the mechanism by which prions change their shape
and aggregate might be put to good use in biological systems. In back-to-back papers in the December
26 issue of Cell, researchers ascribe prion-like properties to an elegant mechanism involved in
maintaining memory.

Susan Lindquist, director of the Massachusetts Institute of Technology's Whitehead Institute, and
Eric Kandel, professor of physiology and psychiatry at Columbia University College of Physicians and
Surgeons, describe a protein, cytoplasmic polyadenylation element-binding protein (CPEB), which
appears to mark active synapses. The protein behaves like a prion in yeast cultures, and its
alternative self-perpetuating form-generally associated with disease states for other prions-appears
to be the protein's active form.

Researchers, in looking to understand memory formation, have struggled to comprehend how a neuron
can strengthen specific synapses while leaving others alone. Kandel, who shared the 2000 Nobel Prize
for work on neuronal signaling, has shown that protein synthesis, localized to the dendrites,
enables a function known as long-term facilitation, which is a strengthening of synaptic connections
in the large neurons of the sea slug Aplysia californica.

In the Cell papers, he proposes that CPEB maintains that strengthening process by spurring local
translation of ubiquitous but dormant messages, such as those for structural and regulatory
molecules, which allow a synapse to grow. "It takes sleeping messenger RNAs and it wakes them up,"
Kandel told The Scientist.

Read the rest at The Scientist.com http://www.biomedcentral.com/news/20031229/02

Posted by Robert Karl Stonjek.
 
I suggest the mechanism of addiction is the basis of "long-term facilitation."

On Mon, 29 Dec 2003 22:10:00 +0000 (UTC), "Robert Karl Stonjek" <[email protected]> wrote:

>Good news for prions?
>
>Mad cow and memory: Prion-like proteins proposed to regulate neuronal plasticity By Brendan A Maher
>
>Since their discovery in 1982, prions have been mostly associated with deadly and devastating
>neurodegenerative disorders-notably variant Creutzfeld-Jakob disease and bovine spongiform
>encephalopathy. Nevertheless, some maintain that the mechanism by which prions change their shape
>and aggregate might be put to good use in biological systems. In back-to-back papers in the
>December 26 issue of Cell, researchers ascribe prion-like properties to an elegant mechanism
>involved in maintaining memory.
>
>Susan Lindquist, director of the Massachusetts Institute of Technology's Whitehead Institute, and
>Eric Kandel, professor of physiology and psychiatry at Columbia University College of Physicians
>and Surgeons, describe a protein, cytoplasmic polyadenylation element-binding protein (CPEB), which
>appears to mark active synapses. The protein behaves like a prion in yeast cultures, and its
>alternative self-perpetuating form-generally associated with disease states for other prions-
>appears to be the protein's active form.
>
>Researchers, in looking to understand memory formation, have struggled to comprehend how a neuron
>can strengthen specific synapses while leaving others alone. Kandel, who shared the 2000 Nobel
>Prize for work on neuronal signaling, has shown that protein synthesis, localized to the dendrites,
>enables a function known as long-term facilitation, which is a strengthening of synaptic
>connections in the large neurons of the sea slug Aplysia californica.
>
>In the Cell papers, he proposes that CPEB maintains that strengthening process by spurring local
>translation of ubiquitous but dormant messages, such as those for structural and regulatory
>molecules, which allow a synapse to grow. "It takes sleeping messenger RNAs and it wakes them up,"
>Kandel told The Scientist.
>
>Read the rest at The Scientist.com http://www.biomedcentral.com/news/20031229/02
>
>Posted by Robert Karl Stonjek.
 
"James Michael Howard" <[email protected]> wrote in message
news:[email protected]...
> I suggest the mechanism of addiction is the basis of "long-term
facilitation."

As I understand (or perhaps misunderstand) what you wrote, I think that is a very wrong suggestion!

The mechanism of addiction is a mechanism whereby primarily and potentially *painful* excitations
[concurrently chronically caused, or being largely chronic because of having been condtioned-in by
some not necessarily any longer environmentally present, adverse (absence as well as presence type)
environmental feature] are being selectively blocked or suppressed.

Moreover, aside from the "classic" addictions to various exogenous drugs, such signals (caused by a
***** or its inevitably chronic aftermath CURSES) may be become *rerouted*, and so (thus
disassociated), also come to insidiously motivate mental nad/or behavioural addictions.

P
 
There is no denying that neurochemical imbalances *can* be induced by drugs of addiction WITHOUT an
individual's brain having been primed to become more readily thus unbalanced by having had CURSES
(type memories) "put" into it by the individual having "been in *****";

In the 'ideal' case of a purely chemically induced addiction, positively behaviour reinforcing
receptors and transmitters that correlate with pleasure (even if they do not most centrally/directly
cause pleasure) get to be (in respect of receptors) desensitized , and/or the rate of production of
such transmitters becomes down-regulated because of the artificial supply of some, to a pleasurable
actention focusing effect directly or indirectly receptor key turning hence neurotransmitter
mimicking [what a mouthful :->], exogenous chemical being ingested.

In laboratory experiments where animals are enabled to electrically enhance the firing rate of
positive reward/pleasure generating neurons (by directly stimulating neurons that release *both*
dopamine and the excitatory transmitter glutamate from their axon terminals) the artifical feed-
forward loop thus established is so strong that it can well illustrate *the strength* (not the
specific chemical and neurophysiological pathways) of the "addiction priming" effect of plenty of
accumulated CURSES (permanently hypersensitized states of glutamate and substance P utilization or
involving neurons in the amygdala region in *perhaps predominantly* the subdominant hemisphere) in
an naturally chemically and/or behaviourally addicted individual's brain.

Apropos which, it can be noted cell bodies containing substance P and dopamine are part of the
substantia nigra. And the same neurons that secrete dopamine may also release glutamate.

http://www.google.com.au/search?q=cache:0hQLaVweQkAJ:axon.bhs.mq.edu.au/cbla ha/PDF/SYNOP.pdf+excitatory+transmitter+dopamine&hl=en&ie=UTF-
8

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=8985891&dopt=Abstract

http://www.ucsf.edu/cnba/Center/mem_edwards.htm
 
Correction: Within the word-sequence "utilization or involving" please replace the "or" with a ",".