Department of Physics, Chemistry and Biology (IFM)

Understanding the underlying mechanisms of relapse to addiction is one of the issues in addiction treatment. Cocaine has a high risk of relapse even after a long period of abstinence.

Striatum, including the nucleus accumbens, is an anatomical area of brain which plays roles in relapse to addiction. It is mainly comprised of dopaminergic neurons called medium-sized spiny neurons (MSNs) divided into D1R- and D2R-expressing neurons.

Although the role of the striatum/nucleus accumbens in addiction is well established, the proportion of each D1 and D2 MSNs contribution, and the specific underlying neurobiological mechanisms of plasticity changes after cocaine administrations that underlie addiction relapse are poorly understood.

In this aspect, the role of the Metabotropic Glutamate Receptor 5 (mGluR5) which is a glutamatergice receptor expressed on both MSN populations is potentially interesting.

A novel mouse line, mGluR5^KD-D1 in which mGluR5 is selectively knocked-down in dopamine D1 receptor expressing neurons, was used to observe the function of mGluR5 in D1R neurons. We aimed to show if the construct is expressed only in D1R- and not in D2R- expressed neurons.

To link the function of mGluR5 in D1R neurons to these behaviour changes, it is important to test if our construct is expressed in the accurate location which is D1-R expressing neurons. Consequently, the aim of this study was to show if the construct is expressed only in D1R- and not in D2R-expressed neurons in the striatum.