Fractionating impulsivity and reward-related phenotypes in adolescent mice.

Adolescence is a developmental period characterized by changes in the brain and behavior, including heightened reward seeking, increased impulsivity, and elevated risk-taking behavior. It is also a sensitive period for the development of a number of behavioral and psychiatric disorders associated with pathological phenotypes of reward processing and impulsivity. Landmark human studies are charting the development of impulsivity and other reward-related phenotypes to identify the facets and timecourse of the adolescent phenotype.

Caffeine Delays Ethanol-Induced Sedation in .

Caffeine and ethanol are among the most widely available and commonly consumed psychoactive substances. Both interact with adenosine receptor-mediated signaling which regulates numerous neurological processes including sleep and waking behaviors. In mammals, caffeine is an adenosine receptor antagonist and thus acts as a stimulant.

A Role for Serotonin in Modulating Opposing Drive and Brake Circuits of Impulsivity.

Impulsivity generally refers to a deficit in inhibition, with a focus on understanding the neural circuits which constitute the "brake" on actions and gratification. It is likely that increased impulsivity can arise not only from reduced inhibition, but also from a heightened or exaggerated excitatory "drive." For example, an action which has more vigor, or is fueled by either increased incentive salience or a stronger action-outcome association, may be harder to inhibit.

Serotonin 1B receptor effects on response inhibition are independent of inhibitory learning.

Impulsivity is defined in terms of deficits in instrumental response inhibition, when the inability to withhold an action produces a negative outcome. However, there are many behavioral and cognitive constructs which theoretically could contribute to disordered impulsivity, including Pavlovian responding, which few studies have considered in this context. In the present set of studies, we examine Pavlovian inhibitory learning and excitatory responding in a mouse model for dysregulated impulsivity, specifically, mice lacking the serotonin 1B receptor (5-HTR).

A role for reward valuation in the serotonergic modulation of impulsivity.

Rationale: Impulsive behavior is a deleterious component of a number of mental health disorders but has few targeted pharmacotherapies. One contributing factor to the difficulty in understanding the neural substrates of disordered impulsivity is the diverse presentations of impulsive behavior. Defining the behavioral and cognitive processes which contribute to different subtypes of impulsivity is important for understanding the neural underpinnings of dysregulated impulsive behavior.