Navigation Links
MIT researchers reveal how the brain keeps eyes on the prize
Date:8/4/2013

n structure known to be important in reinforcement learning. They teamed up with Paul Phillips of the University of Washington, who has developed a technology called fast-scan cyclic voltammetry (FSCV) in which tiny, implanted, carbon-fiber electrodes allow continuous measurements of dopamine concentration based on its electrochemical fingerprint.

"We adapted the FSCV method so that we could measure dopamine at up to four different sites in the brain simultaneously, as animals moved freely through the maze," explains first author Mark Howe, a former graduate student with Graybiel who is now a postdoc in the Department of Neurobiology at Northwestern University. "Each probe measures the concentration of extracellular dopamine within a tiny volume of brain tissue, and probably reflects the activity of thousands of nerve terminals."

Gradual increase in dopamine

From previous work, the researchers expected that they might see pulses of dopamine released at different times in the trial, "but in fact we found something much more surprising," Graybiel says: The level of dopamine increased steadily throughout each trial, peaking as the animal approached its goal as if in anticipation of a reward.

The rats' behavior varied from trial to trial some runs were faster than others, and sometimes the animals would stop briefly but the dopamine signal did not vary with running speed or trial duration. Nor did it depend on the probability of getting a reward, something that had been suggested by previous studies.

"Instead, the dopamine signal seems to reflect how far away the rat is from its goal," Graybiel explains. "The closer it gets, the stronger the signal becomes." The researchers also found that the size of the signal was related to the size of the expected reward: When rats were trained to anticipate a larger gulp of chocolate milk, the dopamine signal rose more steeply to a higher final concentration.

In some t
'/>"/>

Contact: Kimberly Allen
allenkc@mit.edu
617-253-2702
Massachusetts Institute of Technology
Source:Eurekalert

Page: 1 2 3

Related biology news :

1. Mount Sinai researchers develop first successful laboratory model for studying hepatitis C
2. Montana State University researchers highlight bears use of Banff highway crossings
3. HudsonAlpha and UAB researchers work to identify optimal treatments for ER+ breast cancer
4. UPCI researchers target cell sleep to lower chances of cancer recurrence
5. U-M researchers land $2M grant to cooperate with nature on growing algae for energy
6. UT Southwestern researchers identify novel mechanism that helps stomach bug cause illness
7. Researchers uncover cellular mechanisms for attention in the brain
8. Notre Dame researchers develop system that uses a big data approach to personalized healthcare
9. U of M researchers unveil nations first porcine virus rapid detection test
10. Researchers reveal the clearest new pictures of immune cells
11. Researchers describe potential for MERS coronavirus to spread internationally
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:7/10/2014)... stabilize or even improve the state of fisheries ... in the Mediterranean has deteriorated over the past ... fish species reported in the Cell Press journal ... call for stringent monitoring of Mediterranean fishing activities, ... plans in Mediterranean waters. , Their data show ...
(Date:7/10/2014)... Poor peepers are a problem, even if you are ... an imperious predator, scouring the shallow waters for any ... eye exam by Yale University scientists, you,re reduced to ... night. , Such is the lot of the giant ... new paper by Yale paleontologists, published in the journal ...
(Date:7/10/2014)... controversy centres around a family of enzymes known as ... group in their active site. At the centre of ... becomes oxidised (ferryl) when a reacting heme is in ... has remained unanswered for decades is whether this oxidation ... group (OH). Resolving this fundamental question has implications for ...
Breaking Biology News(10 mins):Mediterranean fish stocks show steady decline 2Extinct sea scorpion gets a Yale eye exam, with surprising results 2Neutron crystallography solves long-standing biological mystery 2Neutron crystallography solves long-standing biological mystery 3
... record of oxygen concentration in the earth's atmosphere shows that ... gave mammals the evolutionary boost they needed to dominate the ... and lead author of a paper published Sept. 30 ... have measured the abundance of carbon 13, a byproduct ...
... have learned how to selectively shut down a flyweight-sized ... that may help doctors better understand cancer, birth defects ... be reported this week in the online Proceedings of ... of genetic material called microRNAs. , Once thought to ...
... A team of researchers from the Department of Biochemistry ... the Universitat Autònoma de Barcelona has discovered that tetanus ... a therapy against psychological disorders such as depression, anxiety ... disorders such as Parkinson's disease. , Tetanus toxin is ...
Cached Biology News:Oxygen increase caused mammals to triumph, researchers say 2Micro-molecule plays big role in birth defects 2Tetanus toxin found to have therapeutic properties 2
(Date:7/10/2014)... (PRWEB) July 10, 2014 Understanding the ... channel-expressing cell lines, and the gap that currently exists ... that expand its industry-leading portfolio of validated ion channel ... ion channel-expressing cell lines, as ion channels control many ... control this activity creates the potential to treat a ...
(Date:7/10/2014)... July 10, 2014 Robert Harman, DVM, Founder ... company, is proud to announce the relaunch of his highly ... a new series called “ What are Stem Cells ?” ... honest and straightforward foundation in the basics of stem cell ... on the right type of treatment when considering regenerative medicine. ...
(Date:7/10/2014)... July 10, 2014 Senior supply chain ... professional associations, addressed the challenges of “Reducing Cost, Lead ... Industries” through strategic sourcing. Describing the partnership of the ... Supply Chain Management Institute ( SCMI) of the ... June 24 at the Kroc Institute of Peace and ...
(Date:7/10/2014)... 10, 2014  Kainos Capital, a firm specializing in ... that it has acquired the Slim-Fast brand from Unilever. ... Terms of the transaction were not disclosed. ... business that markets ready-to-drink shakes, powders, bars and snacks ... and in the United Kingdom ...
Breaking Biology Technology:Leader in Ion Channel Research Announces Newly Validated and Re-Engineered Cells 2Leader in Ion Channel Research Announces Newly Validated and Re-Engineered Cells 3Robert Harman, DVM Talks About What Stem Cells are in His Latest Blog Series for Vet-Stem, Inc. 2Robert Harman, DVM Talks About What Stem Cells are in His Latest Blog Series for Vet-Stem, Inc. 3Biotech & Biopharm Supply Chain Management Executives Launch BSMA in San Diego 2Biotech & Biopharm Supply Chain Management Executives Launch BSMA in San Diego 3Biotech & Biopharm Supply Chain Management Executives Launch BSMA in San Diego 4Kainos Capital Acquires Slim-Fast From Unilever 2
... genetics,(Nasdaq: DCGN ) today expressed its enthusiastic ... bill that, many years in the,making, is now ... be signed,promptly by President Bush. GINA would provide ... prohibiting discrimination against,individuals in matters of employment or ...
... April 25 Beckman,Coulter, Inc. (NYSE: BEC ... a quarterly dividend payout of seventeen cents ($0.17) ... 23, 2008 to all stockholders of,record on May ... payout of dividends., (Logo: http://www.newscom.com/cgi-bin/prnh/20031202/BECLOGO ), ...
... BERLIN, April 25 Processes and products based ... the chemical industry in a wide range of ... the field of industrial,biotechnology in Germany will be ... Bioprocessing (April 27-30, 2008) in Chicago, Illinois.,The panel ...
Cached Biology Technology:deCODE Lauds Federal Legislation to Ban Discrimination on the Basis of Genetic Information 2deCODE Lauds Federal Legislation to Ban Discrimination on the Basis of Genetic Information 3deCODE Lauds Federal Legislation to Ban Discrimination on the Basis of Genetic Information 4World Congress on Industrial Biotechnology: Germany Home to Top Biotech Research and Investment 2
...
...
...
... is >95%NEN Radiolabeled Ligands\n\nReceptor-related research has long ... new radiolabeled ligands selected to keep pace ... range of products and services for receptor ... state-of-the-art radioligands. If you do not find ...
Biology Products: