Expression of DREADD Receptors in the Rat Prefrontal Cortex: A Pilot Experiment

Science Center, Bent Corridor

Many different brain areas and different neurotransmitter systems mediate complex behavior such as social behavior. Traditional pharmacological approaches to studying these behaviors are limited because they do not allow for precise manipulation of particular populations of neurons. Chemogenetic approaches, however, enable researchers to precisely control the activity of particular populations of neurons. Designer receptors exclusively activated by designer drugs (DREADD) receptors are one chemogenetic approach to modulating neural activity. These receptors can be expressed in specific populations of neurons, in specific brain areas after being introduced by a viral vector construct. Further, as their name implies the receptors are not activated by endogenous molecules and are only activated following administration of a drug, most commonly CNO. The goal of the current experiment was to verify expression of two viruses after infusion into the medial prefrontal cortex (mPFC) in rats. Rats were either infused with a virus expressing a control protein (eGFP) or an excitatory g-protein coupled receptor (hM3D(Gq)) tagged with mCherry. After recovery from surgery, rats were perfused, brains sectioned and processed using immunohistochemistry. Analysis of the sections verified expression of eGFP and mCherry within the mPFC. We were able to validate the technique; future experiments will use this technique to explore the role of particular neuron populations in the prefrontal cortex in social behaviors.