Navigation Links
Picking apart how neurons learn

Johns Hopkins researchers have used mouse mutants to define critical steps involved in learning basic motor skills. The study focuses on the behavior of two proteins and the specific steps they take to control a neuron's ability to learn by adapting to signals from other nerve cells.

The findings, published in the March 16 issue of Neuron, pull together a growing body of evidence from the field. The study shows definitively that interactions between the PICK1 protein and another group of proteins known as AMPA receptors are critical for specific neurons, called Purkinje cells, in the lower back part of the brain to become de-sensitized to certain molecular signals.

Desensitization to molecular signals from neighboring neurons - a process known as long-term depression, or LTD - is thought to be responsible for several forms of motor learning, one of which is known as the vestibulo-ocular reflex. The vestibulo-ocular reflex coordinates eye movements with head movements, allowing us to perform activities such as reading in a moving automobile.

"We've long known that LTD underlies responses like the vestibulo-ocular reflex. This study gets at the heart of how LTD occurs, specifically how PICK1 controls the Purkinje cell's response to the signaling molecule, glutamate," says Richard L. Huganir, Ph.D., a Howard Hughes Medical Institute investigator and chair of the Solomon H. Snyder Department of Neuroscience at Hopkins.

The first critical step in establishing LTD happens when Purkinje cells swallow up surface proteins called AMPA receptors. Without AMPA receptors on the surface, these cells no longer are able to respond to signals from neighboring neurons. Researchers had known that PICK1 somehow was involved in the swallowing and removal of AMPA receptors, but only in this most recent study did they reveal how.

The investigators used individual nerve cells as well as brain slices from three different populations of genetically m odified mice lacking different proteins required for establishing LTD.

Mice lacking the PICK1 protein are unable to establish LTD or remove AMPA receptors from cell surfaces. When PICK1 is added artificially back into these neurons, AMPA receptors are removed and LTD is restored, showing that PICK1 is necessary for LTD.

Mice lacking the part of the AMPA receptor thought to physically interact with PICK1 also do not establish LTD. This result confirms that PICK1 must physically touch the AMPA receptor for LTD to occur.

The second critical step in establishing LTD involves a chemical change to the AMPA receptor, called phosphorylation. Mice lacking a small part of the AMPA receptor - the part where phosphorylation is thought to occur - do not undergo LTD. This result confirms that phosphorylation is an essential step toward LTD.

With these three different mouse populations in hand, the research team is poised to further dissect the molecular mechanisms behind learning. "The next step is to determine whether LTD is crucial for motor learning, the so-called holy grail in the field," says one of the study's co-first authors, Jordan Steinberg, an M.D., Ph.D. candidate at Hopkins.


'"/>

Source:Johns Hopkins Medical Institutions


Related biology news :

1. Picking particles faster than one at a time
2. Tiny roundworms telomeres help scientists to tease apart different types of aging
3. First real-time view of developing neurons reveals surprises, say Stanford researchers
4. One gene links newborn neurons with those that die in diseases such as Alzheimers
5. Researchers make surprise discovery that some neurons can transmit three signals at once
6. Speak up: Louder neurons form more connections
7. Eating, body weight regulated by specific neurons
8. New neurons take baby steps in the adult brain
9. Algal protein in worm neurons allows remote control of behavior by light
10. Researchers get neurons and silicon talking
11. Mechanism for memory revealed in neurons of electric fish
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:11/15/2016)... , Nov 15, 2016 Research and ... Global Forecast to 2021" report to their offering. ... ... USD 16.18 Billion by 2021 from USD 6.21 Billion in 2016, ... Growth of the bioinformatics market is driven by the ...
(Date:6/22/2016)... 22, 2016  The American College of Medical Genetics and ... Magazine as one of the fastest-growing trade shows during ... the Bellagio in Las Vegas . ... of growth in each of the following categories: net square ... number of attendees. The 2015 ACMG Annual Meeting was ranked ...
(Date:6/20/2016)... 2016 Securus Technologies, a leading provider ... public safety, investigation, corrections and monitoring announced that ... has secured the final acceptance by all three ... Access Systems (MAS) installed. Furthermore, Securus will have ... installed by October, 2016. MAS distinguishes between legitimate ...
Breaking Biology News(10 mins):
(Date:12/8/2016)... ... December 08, 2016 , ... From wearable devices that can ... sports. On Thursday, December 15th a panel of entrepreneurs, innovators and a Philadelphia ... at a Smart Talk session. Smart Talk will run from 8:30 – 10:30 ...
(Date:12/8/2016)... , ... December 08, 2016 , ... ... to control cells — optogenetics — is key to exciting advances in the ... art, spatially patterned light projected via free-space optics stimulates small, transparent organisms and ...
(Date:12/8/2016)... ... December 08, 2016 , ... KBioBox llc announced today ... demand KbioBox developed a sophisticated “3 click” gene dditing off target analysis program ... new website, https://www.kbiobox.com/ and powered by the company’s proprietary BioEngine. ...
(Date:12/8/2016)... 8, 2016 Soligenix, Inc. (OTCQB: SNGX) (Soligenix ... developing and commercializing products to treat rare diseases where ... it will be hosting an Investor Webcast Event Friday, ... origins of innate defense regulators (IDRs) as a new ... mucositis and the recently announced and published Phase 2 ...
Breaking Biology Technology: