Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


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 were 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."

Heidi Hardman | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

nachricht Researchers Discover New Anti-Cancer Protein
22.03.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>