Remembering where to get high

11.01.2017, 14:13 | Wissenschaft | Autor: | Jetzt kommentieren

Heidelberg, 11 January 2017 − Addiction-related memories are exceptionally strong and stable, suggesting that addictive drugs remodel the brain’s circuitry in a prominent and lasting way. In the past decade, researchers have used mouse models to unravel how cellular changes in the nucleus accumbens (NAc), a brain structure involved in action selection associated with arousal and reward, may contribute to addiction-related behavior. Whereas neuronal remodeling in the NAc explains a wide range of addictive behaviors, it is not required for all of them, according to a study published today in The EMBO Journal.

A research team led by Oliver Schlüter (University of Pittsburgh, PA, USA) found that cocaine-induced place preference in mice – returning to places where the drug was previously received – does not depend on lasting rewiring of neurons in the NAc. This finding is an important step towards a better understanding of the cellular and molecular underpinnings of addictive behavior, paving the way for the development of effective therapeutics.

Taking cocaine leads to the generation of immature neuronal contacts called silent synapses in the NAc. Silent synapses, as the name indicates, are not very active. However, after quitting drug abuse, they mature and become stronger, or “unsilenced”, as researchers call it. Unsilencing synapses leads to massive NAc rewiring during drug withdrawal and forms the basis of many addictive behaviors. The process may explain why drug craving often increases over time in the first weeks of abstinence.

Previous work on silent synapse-based NAc remodeling has focused on addiction paradigms where animals learn to associate an activity, like pressing a lever or poking their nose into a hole, with receiving drugs. This type of learning is often referred to as “operational conditioning”. In their present study, Schlüter and his colleagues tested a form of “Pavlovian learning”, where the animal learns passively. Mice were injected with cocaine and placed into one of two compartments of a cage to learn to associate cocaine with the smell, feel and look of that location. After a withdrawal phase, the mice were tested for their memory of the drug-context association. When they were placed back into the two-compartment cage they preferred to reside in the compartment they had learned to associate with feeling high.

The researchers then tested if this learning paradigm would also lead to a rewiring of the NAc and found that it did. Just like in operational conditioning paradigms, silent synapses formed and were unsilenced during withdrawal. But was this rewiring also essential for the mice to remember place preference after withdrawal?

To address this question, the researchers made use of mice with mutations that affect different aspects of synapse unsilencing. They found that mice remember the place where they received cocaine even if synapse unsilencing in the NAc is impaired. Thus, whereas synapse unsilencing and NAc remodeling underlies many addictive behaviors, cocaine-induced place preference is not one of them. This result is an important step towards a better understanding of the molecular and cellular basis of addiction.

Calcium-permeable AMPA Receptors and Silent Synapses in Cocaine-conditioned Place Preference
Shukla A, Beroun A, Panopoulou M, Neumann PA, Grant SGN, Olive MF, Dong Y, Schlüter OM
Read the paper: DOI: 10.15252/embj.201695465

Quelle: idw

Weitere Nachrichten zum Thema
  • BildCareers with an MBA. “I Design Innovative Care Models for the Health Care Market” (08.05.2013, 17:10)
    Part-time MBA graduate of HHL Leipzig Graduate School of Management works as Chief Executive Officer of Universitätsklinikum Schleswig-Holstein (UKSH) / Portraits of HHL graduates on .Dr. Christian Elsner is a graduate (2005) of the first...
  • Bild65 Jahre 'nakba' - Die Katastrophe der Palästinenser (07.05.2013, 11:10)
    Am 15. Mai 2013 wird zum 65. Mal der Nakba erinnert, dem Exodus der arabischen Bevölkerung aus Palästina nach der Gründung des Staates Israel 1948. Zu diesem Anlass stehen die beiden WissenschaftlerInnen Dr. Anaheed Al-Hardan (ICI Berlin Institute...
  • BildTooth brushing - but how? (06.06.2012, 08:10)
    Medical Psychology examines together with dentistry and movement sciences ways to optimize oral hygiene skills.Daily oral hygiene is a health behavior shown with considerable consistency in Germany. Nearly 70% of the Germans report to brush their...
  • BildComputer simulation of memory cells (08.11.2011, 14:10)
    DZNE scientists and their US colleagues have received US$1.5 million in funding to research learning and memory using computer modelsAs part of a transnational funding initiative entitled ‘German–US Collaboration in Computational Neuroscience’,...
  • BildDifferent signal paths for spontaneous and deliberate activation of memories (11.03.2010, 09:00)
    Entirely different signal paths and parts of the brain are involved when you try to remember something and when you just happen to remember something, prompted by a smell, a picture, or a word, for instance. This is shown by Kristiina Kompus in...
  • BildRemembering in old age (11.02.2010, 19:00)
    New interdiscplinary study on the generation of german war childrenEndless nights of air-raids, harrowing treks after being driven out of the family home, rape and threats: the generation of german people born between 1930 and 1945 suffered...
  • BildSevere stress can cause stroke (01.10.2009, 12:00)
    Many patients urgently admitted to hospital with cerebral infarction state that they were under great stress over a prolonged period prior to suffering their stroke, is shown in a unique patient study conducted in cooperation between the...
  • BildEthologische Tagung: Verhaltensweisen bei Mensch und Tier (09.02.2009, 13:00)
    Mit den Mechanismen und dem Anpassungswert von Verhaltensweisen bei Mensch und Tier befasst sich die 4. Thementagung der Ethologischen Gesellschaft, die vom 12. bis 14. Februar 2009 an der Universität Göttingen stattfindet. Die Organisatoren vom...
  • BildEröffnung des Courant Forschungszentrums "Evolution des Sozialverhaltens" (06.02.2009, 16:00)
    Das Courant Forschungszentrum "Evolution des Sozialverhaltens", das die Universität Göttingen im Rahmen ihres "Zukunftskonzeptes" in der Exzellenzinitiative eingerichtet hat, wird am Donnerstag, 12. Februar 2009, offiziell eröffnet: Die...
  • BildUnpleasant memories from intensive care (19.09.2006, 10:00)
    "Being cared for in an intensive care unit (ICU) can never be an especially positive experience. But at any rate it should not mean that the care improves the patient's physical condition only to leave him or her with severe mental problems!" This...

Ähnliche Themen in den JuraForen

    Kommentar schreiben

    45 - Sieb.e_n =

    Bisherige Kommentare zur Nachricht (0)

    (Keine Kommentare vorhanden)

    Fragen Sie einen Anwalt!
    Anwälte sind gerade online.
    Schnelle Antwort auf Ihre Rechtsfrage.


    Kostenlose aktuelle Urteile und Rechtstipps per E-Mail:

    Top 10 Orte in der Anwaltssuche


    Durchsuchen Sie hier nach bestimmten Begriffen:

    © 2003-2017 — Alle Rechte vorbehalten. Keine Vervielfältigung, Verbreitung oder Nutzung für kommerzielle Zwecke.