This volume explores the latest techniques used to better understand the brain reward system with respect to neurotransmitters, brain structures, and connectivity. This book aims to show readers tested laboratory protocols to study neural circuitry and biological processes implicated in reward, and in neuropsychiatric disorders such as substance use disorders. The chapters are organized into four parts. Part One addresses classical techniques to study the brain reward system, including the curve shift paradigm in intracranial self-stimulation, stereotaxic surgery in rodents, and the use of brain lesions. Part Two focuses on neurochemical, behavioral, and chemogenetic techniques such as immunofluorescence for assessing adult hippocampal neurogenesis, and fast-scan voltammetry. Part Three highlights methods used to assess the rewarding potential of drugs including intracranial self-stimulation combined with drug injection, and the use of viral vectors. The Fourth Part introduces imaging and electrophysiology techniques such as positron emission tomography, in vivo electrophysiology, and fiber photometry. In the Neuromethods series style, chapters include the kind of detail and key advice from the specialists needed to get successful results in your laboratory. Cutting-edge and thorough, The Brain Reward System is a valuable resource for researchers interested in learning more about the current methods used to study the delineation of the brain reward system.