The relevance of serotonergic psychedelics is emphasized by a renewed recognition of their potential therapeutic benefits, resulting in a so-called ‘psychedelic renaissance’. Furthermore, structurally diverse groups of psychedelic new psychoactive substances (NPS) have emerged on the drug market. However, these substances still remain incompletely characterized in terms of their pharmacological effect, even though it is established that they have activation of the serotonin 5-HT2A receptor (5-HT2AR) as a common mechanism of action. This receptor is present at the cell membrane and translates extracellular signals (such as the presence of a drug or endogenous ligand) into an intracellular effect (induction of cellular pathway). Because of the incomplete pharmacological characterization, it is still elusive which of the effects of the 5-HT2AR are responsible for the psychedelic nature of some -but not all- 5-HT2AR agonists. Therefore, this research project aims to shed more light on a panel of intracellular signaling pathways that are induced upon 5-HT2AR activation. This will be accomplished via the development, optimization, and application of novel biological (cell-based) assays, complementing previously developed and commercially available assays. The envisioned outcomes will be a furthered insight into both the effects exerted by psychedelics on the cellular level, as well as a broader understanding of why substances with different chemical nature behave differently.