The mesolimbic pathway, sometimes referred to as the reward pathway, is a dopaminergic pathway in the brain. The pathway connects the ventral tegmental area in the midbrain to the ventral striatum of the basal ganglia in the forebrain. The ventral striatum includes the nucleus accumbens and the olfactory tubercle.
The nucleus accumbens is a region in the basal forebrain rostral to the preoptic area of the hypothalamus. The nucleus accumbens and the olfactory tubercle collectively form the ventral striatum. The ventral striatum and dorsal striatum collectively form the striatum, which is the main component of the basal ganglia. The dopaminergic neurons of the mesolimbic pathway project onto the GABAergic medium spiny neurons of the nucleus accumbens and olfactory tubercle. Each cerebral hemisphere has its own nucleus accumbens, which can be divided into two structures: the nucleus accumbens core and the nucleus accumbens shell. These substructures have different morphology and functions.
Dopamine receptors are a class of G protein-coupled receptors that are prominent in the vertebrate central nervous system (CNS). Dopamine receptors activate different effectors through not only G-protein coupling, but also signaling through different protein interactions. The neurotransmitter dopamine is the primary endogenous ligand for dopamine receptors.
Motivational salience is a cognitive process and a form of attention that motivates or propels an individual's behavior towards or away from a particular object, perceived event or outcome. Motivational salience regulates the intensity of behaviors that facilitate the attainment of a particular goal, the amount of time and energy that an individual is willing to expend to attain a particular goal, and the amount of risk that an individual is willing to accept while working to attain a particular goal.
In internal medicine, relapse or recidivism is a recurrence of a past condition. For example, multiple sclerosis and malaria often exhibit peaks of activity and sometimes very long periods of dormancy, followed by relapse or recrudescence.
Neuropharmacology is the study of how drugs affect function in the nervous system, and the neural mechanisms through which they influence behavior. There are two main branches of neuropharmacology: behavioral and molecular. Behavioral neuropharmacology focuses on the study of how drugs affect human behavior (neuropsychopharmacology), including the study of how drug dependence and addiction affect the human brain. Molecular neuropharmacology involves the study of neurons and their neurochemical interactions, with the overall goal of developing drugs that have beneficial effects on neurological function. Both of these fields are closely connected, since both are concerned with the interactions of neurotransmitters, neuropeptides, neurohormones, neuromodulators, enzymes, second messengers, co-transporters, ion channels, and receptor proteins in the central and peripheral nervous systems. Studying these interactions, researchers are developing drugs to treat many different neurological disorders, including pain, neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, psychological disorders, addiction, and many others.
Sensitization is a non-associative learning process in which repeated administration of a stimulus results in the progressive amplification of a response. Sensitization often is characterized by an enhancement of response to a whole class of stimuli in addition to the one that is repeated. For example, repetition of a painful stimulus may make one more responsive to a loud noise.
Kent C. Berridge is an American academic, currently working as a professor of psychology (biopsychology) and neuroscience at the University of Michigan. Berridge was a joint winner of the 2018 Grawemeyer Award for Psychology.
The reward system is a group of neural structures responsible for incentive salience, associative learning, and positively-valenced emotions, particularly ones involving pleasure as a core component. Reward is the attractive and motivational property of a stimulus that induces appetitive behavior, also known as approach behavior, and consummatory behavior. A rewarding stimulus has been described as "any stimulus, object, event, activity, or situation that has the potential to make us approach and consume it is by definition a reward". In operant conditioning, rewarding stimuli function as positive reinforcers; however, the converse statement also holds true: positive reinforcers are rewarding.
Methamphetamine is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug and less commonly as a second-line treatment for attention deficit hyperactivity disorder and obesity. Methamphetamine was discovered in 1893 and exists as two enantiomers: levo-methamphetamine and dextro-methamphetamine. Methamphetamine properly refers to a specific chemical substance, the racemic free base, which is an equal mixture of levomethamphetamine and dextromethamphetamine in their pure amine forms, but the hydrochloride salt, commonly called crystal meth, is widely used. Methamphetamine is rarely prescribed over concerns involving human neurotoxicity and potential for recreational use as an aphrodisiac and euphoriant, among other concerns, as well as the availability of safer substitute drugs with comparable treatment efficacy such as Adderall and Vyvanse. Dextromethamphetamine is a stronger CNS stimulant than levomethamphetamine.
Protein fosB, also known as FosB and G0/G1 switch regulatory protein 3 (G0S3), is a protein that in humans is encoded by the FBJ murine osteosarcoma viral oncogene homolog B (FOSB) gene.
Behavioral addiction, process addiction, or non-substance-related disorder is a form of addiction that involves a compulsion to engage in a rewarding non-substance-related behavior – sometimes called a natural reward – despite any negative consequences to the person's physical, mental, social or financial well-being. In the brain's reward system, a gene transcription factor known as ΔFosB has been identified as a necessary common factor involved in both behavioral and drug addictions, which are associated with the same set of neural adaptations.
Eric J. Nestler is the Nash Family Professor of Neuroscience, Director of the Friedman Brain Institute, and Dean for Academic Affairs at the Icahn School of Medicine at Mount Sinai and Chief Scientific Officer of the Mount Sinai Health System. His research is focused on a molecular approach to drug addiction and depression.
Addiction is a state characterized by compulsive engagement in rewarding stimuli, despite adverse consequences. The process of developing an addiction occurs through instrumental learning, which is otherwise known as operant conditioning.
Antonello Bonci is an Italian-American neurologist and a neuropsychopharmacologist specialized in the long-term effects of drug exposure on the brain. In August 2019, he became president of Global Institutes on Addictions Miami. Bonci was previously the scientific director of the National Institute on Drug Abuse and a professor at the University of California, San Francisco.
Yasmin Hurd is the Ward-Coleman Chair of Translational Neuroscience and the Director of the Addiction Institute at Mount Sinai. Hurd holds appointments as faculty of Neuroscience, Psychiatry, Pharmacology and Systems Therapeutics at the Icahn School of Medicine at Mount Sinai in New York City and is globally recognized for her translational research on the underlying neurobiology of substance use disorders and comorbid psychiatric disorders. Hurd's research on the transgenerational effects of early cannabis exposure on the developing brain and behavior and on the therapeutic properties of cannabidiol has garnered substantial media attention. In 2017, Dr. Hurd was elected to the National Academy of Medicine and, in 2022, Dr. Hurd was elected to the National Academy of Sciences (NAS).
Bita Moghaddam is an Iranian-American neuroscientist and author. She is currently the Ruth Matarazzo Professor of Behavioral Neuroscience at Oregon Health & Science University. Moghaddam investigates the neuronal processes underlying emotion and cognition as a first step to designing strategies to treat and prevent brain illnesses.
Lisa Monteggia is an American neuroscientist who is a Professor in the Department of Pharmacology, Psychiatry & Psychology as well as the Barlow Family Director of the Vanderbilt Brain Institute at Vanderbilt University in Nashville, Tennessee. Monteggia probes the molecular mechanisms underlying psychiatric disorders and has made critical discoveries about the role of the neurotrophins in antidepressant efficacy, the antidepressant mechanisms of Ketamine, as well as the epigenetic regulation of synaptic transmission by MeCP2.
Camilla Bellone is an Italian neuroscientist and assistant professor in the Department of Basic Neuroscience at the University of Geneva, in Switzerland. Bellone's laboratory explores the molecular mechanisms and neural circuits underlying social behavior and probes how defects at the molecular and circuit level give rise to psychiatric disease states such as Autism Spectrum Disorders.
Ilana B. Witten is an American neuroscientist and professor of psychology and neuroscience at Princeton University. Witten studies the mesolimbic pathway, with a focus on the striatal neural circuit mechanisms driving reward learning and decision making.
