?1b-Adrenergic Receptor Localization and Relationship to the D1-Dopamine Receptor in the Rat Nucleus Accumbens.

ABSTRACT: The ?1-adrenergic receptors (?1ARs) have been implicated in numerous actions of the brain, including attention and wakefulness. Additionally, they have been identified as contributing to disorders of the brain, such as drug addiction, and recent work has shown a role of these receptors in relapse to psychostimulants. While some functionality is known, the actual subcellular localization of the subtypes of the ?1ARs remains to be elucidated. Further, their anatomical relationship to receptors for other neurotransmitters, such as dopamine (DA), remains unclear. Therefore, using immunohistochemistry and electron microscopy techniques, this study describes the subcellular localization of the ?1b-adrenergic receptor (?1bAR), the subtype most tied to relapse behaviors, as well as its relationship to the D1-dopamine receptor (D1R) in both the shell and core of the rat nucleus accumbens (NAc). Overall, ?1bARs were found in unmyelinated axons and axon terminals with some labeling in dendrites. In accordance with other studies of the striatum, the D1R was found mainly in dendrites and spines; therefore, colocalization of the D1R with the ?1bAR was rare postsynaptically. However, in the NAc shell, when the receptors were co-expressed in the same neuronal elements there was a trend for both receptors to be found on the plasma membrane, as opposed to the intracellular compartment. This study provides valuable anatomical information about the ?1bAR and its relationship to the D1R and the regulation of DA and norepinephrine (NE) neurotransmission in the brain which have been examined previously.

SUBMITTER: Mitrano DA 

PROVIDER: S-EPMC5809204 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature