Navigation Links
New clue to cocaine addicts' quirky behavior

Researchers working with rats have zeroed in on the brain circuitry mechanism whose disruption contributes to the impulsive behavior seen in users of cocaine as well as other psychostimulant drugs. The same circuitry has been implicated in such disorders as schizophrenia, depression, and post-traumatic stress disorder, wrote the researchers.

Yukiori Goto and Anthony A. Grace of the University of Pittsburgh described their findings in the July 21, 2005, issue of Neuron. In their studies, they sought to understand the effects of cocaine sensitization on the connections between two higher brain regions--the prefrontal cortex and the hippocampus--and the nucleus accumbens, which is the region in the limbic system involved in processing reward behavior. The prefrontal cortex is involved in processing information, and the hippocampus is involved in learning and memory.

The connections to the nucleus accumbens seem to be bidirectional, said the researchers, and the interactions with the prefrontal cortex and hippocampus could affect the "plasticity" of connections in the neurons of the nucleus accumbens. This means that disruptions to the normal connections could affect behavior.

The researchers' electrophysiological studies of the effects of cocaine on this circuitry demonstrated that the drug did disrupt this normal plasticity. They found that the cocaine induced abnormal enhancement of neuronal connections--a phenomenon called long-term potentiation (LTP).

The researchers also performed behavioral studies on the cocaine-sensitized rats, to explore the behavioral effects of this disruption. In these studies, they placed the rats in a plus-shaped maze. The rats were taught that in response to a visual cue they should turn left or right toward one arm or the other of the maze to obtain a piece of cereal.

Goto and Grace found that, while the cocaine-sensitized rats learned the correct response strategy faster than normal rats, they wer e significantly less able to change strategies when they were required to ignore the cue and always make a left or right turn to receive the reward.

"Thus, although abnormally induced LTP by psychostimulants at limbic inputs might not interfere with learning a response strategy, it may reduce the capacity of these animals to consider alternate response strategies," concluded Goto and Grace. "In this way, the disruption of synaptic plasticity by cocaine sensitization may contribute to the affective- and context-inappropriate impulsive behaviors that are characteristic of drug addiction."

This work was supported by USPHS and National Alliance for Research on Schizophrenia and Depression Young Investigator Award. Y.G. is NARSAD Essel Investigator.

Goto and Grace: "Dopamine-dependent Interactions between Limbic and Prefrontal Cortical Plasticity in the Nucleus Accumbens: Disruption by Cocaine Sensitization" Publishing in Neuron, Vol. 47, July 21, 2005, pages 255?66. DOI 10.1016/j.neuron.2005.06.017. www.neuron.org


'"/>

Source:Cell Press


Related biology news :

1. Portable cocaine sensor developed at UC Santa Barbara
2. High resolution snapshots detail dynamics of a cocaine antibody
3. Genetically altered mice no longer like cocaine
4. High-tech research shows cocaine changes proteins and brain function
5. Altered perception of reward in human cocaine addiction
6. Scientists design simple dipstick test for cocaine, other drugs
7. Prenatal cocaines lasting cellular effects
8. Rensselaer researchers develop approach that predicts protein separation behavior
9. Scientists uncover new clues about brain function in human behavior
10. Single gene is genetic switch for fly sexual behavior
11. Using the genomic shortcut to predict bacterial behavior
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/15/2016)... April 15, 2016  A new partnership announced ... accurate underwriting decisions in a fraction of the ... priced and high-value life insurance policies to consumers ... With Force Diagnostics, rapid testing (A1C, Cotinine ... readings (blood pressure, weight, pulse, BMI, and activity ...
(Date:3/31/2016)... BOCA RATON, Florida , March 31, 2016 /PRNewswire/ ... LEGX ) ("LegacyXChange" or the "Company") ... presentation for potential users of its soon to be ... The video ( https://www.youtube.com/channel/UCyTLBzmZogV1y2D6bDkBX5g ) will also ... by the use of DNA technology to an industry ...
(Date:3/22/2016)... , March 22, 2016 ... report "Electronic Sensors Market for Consumer Industry by Type ... Others), Application (Communication & IT, Entertainment, Home ... Global Forecast to 2022", published by MarketsandMarkets, ... expected to reach USD 26.76 Billion by ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... 27, 2016  Global demand for enzymes is ... 2020 to $7.2 billion.  This market includes enzymes ... products, biofuel production, animal feed, and other markets) ... biocatalysts). Food and beverages will remain the largest ... consumption of products containing enzymes in developing regions.  ...
(Date:6/27/2016)... ... June 27, 2016 , ... Cancer experts ... they believe could be a new and helpful biomarker for malignant pleural mesothelioma. ... here to read it now. , Biomarkers are components in the blood, ...
(Date:6/27/2016)... (PRWEB) , ... June 27, 2016 , ... ... operations for Amgen, will join the faculty of the University of North ... adjunct professor of strategy and entrepreneurship at UNC Kenan-Flagler, with a focus on ...
(Date:6/24/2016)... 24, 2016  Regular discussions on a range of subjects ... the two entities said Poloz. Speaking at a ... , he pointed to the country,s inflation target, which ... "In certain areas ... have common economic goals, why not sit down and address ...
Breaking Biology Technology: