High resolution imaging to unveil the subcellular layout of the cannabinoid type-1 receptor in rodent models of brain disease

Abstract

The present Thesis focuses on the description of new subcellular localizations of CB1 receptors in normal brain and the study of the CB1 receptor expression in certain pathophysiological states. Different histological techniques have been crucial in defining the CB1 receptor expression and localization at the cellular level. However, it is extremely difficult to identify the subcellular distribution of CB1 receptors in some cell-types due to its low expression level on those cells. Moreover, it remains a key question to know the pattern of the subcellular CB1 receptor expression and distribution under pathological states. The high resolution immunoelectron microscopy applied in this study has shown to be an excellent approach for the fine detection of CB1 receptors in the brain. In particular, the single pre-embedding immunogold method for electron microscopy based on the use of specific primary CB1 receptor antibodies and silver-intensified 1.4 nm gold-labeled Fab' fragments was used, as well as the combined pre-embedding immunogold and immunoperoxidase method that implied the additional use of biotinylated secondary antibodies and avidin-biotin complex for the simultaneous localization of CB1 receptors and protein markers of specific brain cells or synapses.