How the brain stays receptive: Channel protein Pannexin1 is critical for memory and orientation
The channel protein Pannexin1 keeps nerve cells flexible and thus the brain receptive for new knowledge. Together with colleagues from Canada and the U.S., researchers at the Ruhr-Universität Bochum led by the junior professor Dr. Nora Prochnow from the Department of Molecular Brain Research describe these results in PLoS ONE. In the study, mice comprising no Pannexin1 in memory-related brain structures displayed symptoms similar to autism. Their nerve cells lacked synaptic plasticity, i.e. the ability to form new synaptic contacts or give up old contacts based on the level of usage.
Pannexins traverse the cell membrane of vertebrate animals and form large pored channels. They are permeable for certain signalling molecules, such as the energy storage molecule ATP (adenosine triphosphate). The best known representative is Pannexin1, which occurs in abundance in the brain and spinal cord and among others in the hippocampus - a brain structure that is critical for long-term memory. Malfunctions of the pannexins play a role in the development of epilepsy and strokes.
The research team studied mice in which the gene for Pannexin1 was lacking. Using cell recordings carried out on isolated brain sections, they analysed the long-term potentiation in the hippocampus. Long-term potentiation usually occurs when new memory content is built - the contacts between nerve cells are strengthened; they communicate more effectively with each other. In mice without Pannexin1, the long-term potentiation occurred earlier and was more prolonged than in mice with Pannexin1. "It looks at first glance like a gain in long-term memory", says Nora Prochnow. "But precise analysis shows that there was no more scope for upward development." Due to the lack of Pannexin1, the cell communication in general was increased to such an extent that a further increase through the learning of new knowledge was no longer possible. The synaptic plasticity was thus extremely restricted. "The plasticity is essential for learning processes in the brain", Nora Prochnow explains. "It helps you to organise, keep or even to forget contents in a positive sense, to gain room for new inputs."
The absence of Pannexin1 also had an impact on behaviour: when solving simple problems, the animals were quickly overwhelmed in terms of content. Their spatial orientation was limited, their attention impaired and an increased probability for seizure generation occurred. "The behavioural patterns are reminiscent of autism. We should therefore consider the Pannexin1 channel more closely with regard to the treatment of such diseases", says the neurobiologist from Bochum.
According to the scientists' theory, nerve cells lack a feedback mechanism without Pannexin1. Normally the channel protein releases ATP, which binds to specific receptors and thus reduces the release of the neurotransmitter glutamate. Without Pannexin1 more glutamate is released, which leads to increased long-term potentiation. This causes the cell to lose its dynamic equilibrium, which is needed for an efficient learning process.
More information: N. Prochnow, A. Abdulazim, S. Kurtenbach, V. Wildförster, G. Dvoriantchikova , J. Hanske, E. Petrasch-Parwez, V.I. Shestopalov, R. Dermietzel, D. Manahan-Vaughan, G. Zoidl (2012): Pannexin1 stabilizes synaptic plasticity and is needed for learning, PLoS ONE, DOI: 10.1371/journal.pone.0051767
Journal reference: PLoS ONE
Provided by Ruhr-Universitaet-Bochum
- In lab, Pannexin1 restores tight binding of cells that is lost in cancer Jan 30, 2012 | not rated yet | 0
- Two-dimensional learning: Viewing computer images causes long-term changes in nerve cell connections Sep 26, 2011 | not rated yet | 0
- Memory enhanced by sports-cheat drug Sep 09, 2008 | not rated yet | 0
- Long-term methadone treatment can affect nerve cells in brain Aug 15, 2012 | not rated yet | 0
- A mechanism to improve learning and memory Feb 21, 2012 | not rated yet | 0
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
How can there be a term called "intestinal metaplasia" of stomach
9 hours ago Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
- More from Physics Forums - Medical Sciences
More news stories
(Medical Xpress)—Despite spending billions of dollars on research and development, drug companies have been unable to come up with effective treatments for dementia and Alzheimer's Disease (AD). Now, A. ...
Neuroscience 3 hours ago | 4.7 / 5 (3) | 0 |
You're standing near an airport luggage carousel and your bag emerges on the conveyor belt, prompting you to spring into action. How does your brain make the shift from passively waiting to taking action when ...
Neuroscience 3 hours ago | not rated yet | 0 |
(Medical Xpress)—Native peoples in regions where cameras are uncommon sometimes react with caution when their picture is taken. The fear that something must have been stolen from them to create the photo ...
Neuroscience 5 hours ago | 4 / 5 (4) | 0 |
In a remote fishing community in Venezuela, a lone fisherman sits on a cliff overlooking the southern Caribbean Sea. This man –– the lookout –– is responsible for directing his comrades on the water, ...
Neuroscience 7 hours ago | 4 / 5 (1) | 0 |
A drug commonly used to treat depression and anxiety may improve a stress-related heart condition in people with stable coronary heart disease, according to researchers at Duke Medicine.
30 minutes ago | not rated yet | 0 |
40 minutes ago | not rated yet | 0
(HealthDay)—In 2008 to 2010, the prevalence of key health behaviors among U.S. adults varied, with about one in five adults current smokers and 62.1 percent overweight or obese, according to a report presented ...
30 minutes ago | not rated yet | 0
(HealthDay)—Factors such as increased case finding may explain why Michigan had half of the total spinal infections associated with contaminated methylprednisolone acetate in the recent fungal meningitis ...
20 minutes ago | not rated yet | 0
Early use of tracheostomy for mechanically ventilated patients not associated with improved survival
For critically ill patients receiving mechanical ventilation, early tracheostomy (within the first 4 days after admission) was not associated with an improvement in the risk of death within 30 days compared to patients who ...
30 minutes ago | not rated yet | 0
(HealthDay)—Three-quarters of public schools in the metro Atlanta area contain microbes, including bacteria indicating the presence of fecal matter, according to research published in the May 17 issue of ...
10 minutes ago | not rated yet | 0