Effects of Methylphenidate on Default-Mode Network/Task-Positive Network Synchronization in Children With ADHD
Laurent Querne1,2, Sidy Fall1,2, Anne-Gaëlle Le Moing1,2
11 GRAMFC INSERM U1105, Université de Picardie Jules-vernes, France.
Journal of Attention Disorders
|January 15, 2014
Summary
Methylphenidate improved synchronization between brain networks in children with ADHD, reducing response time variability. This suggests that impaired network synchronization contributes to ADHD symptoms.
Area of Science:
- Neuroscience
- Developmental Neuroscience
- Cognitive Neuroscience
Background:
- ADHD is characterized by moment-to-moment variability, potentially linked to disrupted anti-phase synchronization between the default-mode network (DMN) and task-positive network (TPN).
- Understanding the neural mechanisms underlying ADHD variability is crucial for developing effective treatments.
Purpose of the Study:
- To investigate the impact of methylphenidate on TPN/DMN synchronization in children with ADHD.
- To explore the relationship between TPN/DMN synchronization and response time variability in ADHD.
Main Methods:
- Functional magnetic resonance imaging (fMRI) was used to examine brain activity in 11 drug-naive children with ADHD and 11 typically developing (TD) children during a flanker task.
- The ADHD group underwent scanning both without and with methylphenidate treatment.
- Independent component analysis was employed to analyze brain signal synchronization.
Main Results:
- TD children exhibited anti-phase DMN/TPN synchronization.
- Unmedicated ADHD children showed synchronous activity only in the posterior DMN, correlated with response time variability.
- Methylphenidate administration partially restored anti-phase TPN/DMN synchronization, decreased variability, and eliminated the correlation between variability and DMN activity.
Conclusions:
- A failure in TPN/DMN synchronization may underlie the moment-to-moment variability observed in ADHD.
- Methylphenidate appears to enhance TPN/DMN synchronization, which may, in turn, reduce ADHD-related variability.
More Related Videos
13:09Using Brain Activation nir-HEG/Q-EEG and Execution Measures CPTs in a ADHD Assessment Protocol
Published on: April 1, 2018
9.7K
05:48The Adventures of Fundi Intervention Based on the Cognitive and Emotional Processing in Attention Deficit Hyperactive Disorder Patients
Published on: June 12, 2020
5.4K
Related Concept Videos
01:30Attention-Deficit/Hyperactivity Disorder
1.4K
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by persistent inattention, hyperactivity, and impulsivity. It affects approximately 5-8% of children globally, with around 60-70% of cases persisting into adulthood. ADHD has significant implications for educational attainment, social interactions, and occupational success.
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings....
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings....
1.4K
01:29Drugs Affecting Neurotransmitter Synthesis
2.5K
Drugs affecting neurotransmitter synthesis can impact the adrenergic neuron and the synthesis of neurotransmitters. For example, α-methyltyrosine and carbidopa target specific enzymes involved in catecholamine synthesis. α-methyltyrosine inhibits the enzyme tyrosine hydroxylase, which converts tyrosine into dopamine. By blocking this enzyme, α-methyltyrosine reduces dopamine production and other catecholamines. Carbidopa, on the other hand, inhibits the enzyme dopa decarboxylase,...
2.5K
01:24CNS Stimulants: Cocaine, Amphetamines and Cannabinoids
1.5K
CNS stimulants, such as cocaine, amphetamines, and cannabinoids, have varying structures and mechanisms of action that lead to different therapeutic effects and side effects. Cocaine, with its molecular formula C17H21NO4, is a tropane alkaloid and a tertiary amino compound. It has two chemical forms: the hydrochloride salt and the "freebase." The former is in powder form, while the latter involves removing the hydrochloride salt to create a form that can be smoked. Cocaine exerts its...
1.5K
01:25Adrenergic Agonists: Indirect-Acting Agents
2.8K
Indirect-acting adrenergic agonists potentiate the effects of endogenous catecholamines through different mechanisms without directly binding to adrenoceptors.
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...
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...
2.8K
01:21Drugs Affecting Neurotransmitter Release or Uptake
1.8K
Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking...
1.8K