Comparing the Density of Beta-Adrenergic Receptors in the Prefrontal Cortices of Mice

Norepinephrine, a hormone and neurotransmitter, is primarily produced in a brain region called the locus coeruleus and is directly projected to the prefrontal cortex and other areas of the brain. This production and projection of norepinephrine are heavily involved in attention regulation. Norepinephrine regulates attention similarly in all mammals, but there are sex differences in the noradrenergic system, such as differences in locus coeruleus volume and size. Sex differences found in the locus coeruleus may affect norepinephrine transmission to the prefrontal cortex and its regulation of attention behaviors. When norepinephrine reaches the prefrontal cortex, it can bind to alpha- or beta-adrenergic receptors.

This study compares the density of beta-adrenergic receptors in the prefrontal cortex of male and female mice. The hypothesis of this study is that female mice have a lower density of beta-1 adrenergic receptors in the prefrontal cortex than males because they have more potential for norepinephrine release. To test this hypothesis, an RNAscope assay was used to detect beta-1 adrenergic receptor RNA in the tissue of the prefrontal cortex of both male and female mice, and the relative density of these receptors was quantified using ImageJ software. I found that males have more beta-1 adrenergic receptor RNA on average than females. These findings established the relative density of beta-1 adrenergic receptors within the prefrontal cortex in both sexes and provided a better understanding of attention regulation in the prefrontal cortex and its impact on a variety of psychiatric and neurodegenerative disorders.