Mesolimbic pathway

[2] The release of dopamine from the mesolimbic pathway into the nucleus accumbens regulates incentive salience (e.g. motivation and desire for rewarding stimuli) and facilitates reinforcement and reward-related motor function learning;[3][4][5] it may also play a role in the subjective perception of pleasure.

[3][5] The dysregulation of the mesolimbic pathway and its output neurons in the nucleus accumbens plays a significant role in the development and maintenance of an addiction.

The nucleus accumbens and olfactory tubercle are located in the ventral striatum and are primarily composed of medium spiny neurons.

[11] The mesolimbic pathway regulates incentive salience, motivation, reinforcement learning, and fear, among other cognitive processes.

Depletion of dopamine in this pathway, or lesions at its site of origin, decrease the extent to which an animal is willing to go to obtain a reward (e.g. the number of lever presses for intravenous nicotine delivery in rats or time spent searching for food).

[23] An addictive drug is defined as a substance that affects the mesolimbic system directly or indirectly by increasing extracellular levels of dopamine.

[24] Common addictive substances such as cocaine, alcohol, and nicotine have been shown to increase extracellular levels of dopamine within the mesolimbic pathway, preferentially within the nucleus accumbens.