A broad range of severe pathologies such as pain, anxiety, neurodegeneration,hypertension, asthma, as well as some gastrointestinal diseases, are due to receptordysfunction. Some of these pathologies have a tremendous social impact as they involve large population segments, in particular aged people. The systems more frequently involved in these pathologies are adenosinic, adrenergic, aminoacidergic, cholinergic(muscarinic and nicotinic), dopaminergic, imidazoline, triptaminergic, and sigma receptors as well as Wnt pathway. The goals of the research reported in this book intended (i) to obtain more information about structure, functions and dysfunctions of neurotransmitter receptors, (ii) to individuate novel leads to develop useful drugs in the treatment of neuroreceptor dysfunctions. Therefore imidazoline, 1, 4-dioxane and spiropiperidine nuclei were utilized for designing novel a2-adrenergic, imidazoline, dopaminergic, muscarinic, 5-HT1A-serotoninergic and sigma ligands (VII), respectively. Finally, new azaindole analogues have been synthesized as RHO kinase inhibitors (I, II).