Related Experiment Video
Updated: Apr 16, 2026

Three Laboratory Procedures for Assessing Different Manifestations of Impulsivity in Rats
Published on: March 17, 2019
Dissociable rate-dependent effects of oral methylphenidate on impulsivity and D2/3 receptor availability in the
Daniele Caprioli1, Bianca Jupp2, Young T Hong3
1Behavioral Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, Maryland 21224.
Abstract:
We have previously shown that impulsivity in rats is linked to decreased dopamine D2/3 receptor availability in the ventral striatum. In the present study, we investigated, using longitudinal positron emission tomography (PET), the effects of orally administered methylphenidate (MPH), a first-line treatment for attention deficit hyperactivity disorder, on D2/3 receptor availability in the dorsal and ventral striatum and related these changes to impulsivity. Rats were screened for impulsive behavior on a five-choice serial reaction time task. After a baseline PET scan with the D2/3 ligand [(18)F]fallypride, rats received 6 mg/kg MPH, orally, twice each day for 28 d. Rats were then reassessed for impulsivity and underwent a second [(18)F]fallypride PET scan. Before MPH treatment, we found that D2/3 receptor availability was significantly decreased in the left but not the right ventral striatum of high-impulse (HI) rats compared with low-impulse (LI) rats. MPH treatment increased impulsivity in LI rats, and modulated impulsivity and D2/3 receptor availability in the dorsal and ventral striatum of HI rats through inverse relationships with baseline levels of impulsivity and D2/3 receptor availability, respectively. However, we found no relationship between the effects of MPH on impulsivity and D2/3 receptor availability in any of the striatal subregions investigated. These findings indicate that trait-like impulsivity is associated with decreased D2/3 receptor availability in the left ventral striatum, and that stimulant drugs modulate impulsivity and striatal D2/3 receptor availability through independent mechanisms.
More Related Videos
07:30Single Cell Measurement of Dopamine Release with Simultaneous Voltage-clamp and Amperometry
Published on: November 21, 2012
11:26Assessment of Dopaminergic Homeostasis in Mice by Use of High-performance Liquid Chromatography Analysis and Synaptosomal Dopamine Uptake
Published on: September 21, 2017
Related Concept Videos
Attention-Deficit/Hyperactivity Disorder
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings....
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral...
Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance
A study on guinea pigs examined the...
Drugs Affecting Neurotransmitter Synthesis
Drugs Affecting Neurotransmitter Release or Uptake
Adrenergic Agonists: Mixed-Action Agents
Ephedrine and pseudoephedrine lack a catecholamine group, making them less susceptible to degradation by metabolic enzymes. They have increased oral bioavailability and lipophilicity, resulting in a longer duration of action. Their response is reduced by...