Related Experiment Video

Updated: Jul 6, 2026

A Computerized Test Battery to Study Pharmacodynamic Effects on the Central Nervous System of Cholinergic Drugs in Early Phase Drug Development
07:02

A Computerized Test Battery to Study Pharmacodynamic Effects on the Central Nervous System of Cholinergic Drugs in Early Phase Drug Development

Published on: February 11, 2019

Adverse effects of methylene blue on the central nervous system

Laszlo Vutskits1, Adrian Briner, Paul Klauser

  • 1Division of Anesthesiology, University Hospitals of Geneva, and Department of Neuroscience, Faculty of Medicine, Geneva University, Geneva, Switzerland. laszlo.vutskits@hcuge.ch

Anesthesiology
|March 26, 2008
PubMed
Abstract

Insights

Methylene blue (MB) can cause neurotoxicity, impacting central nervous system function and neuronal structure. This study investigated MB

Area of Science:

  • Neuroscience
  • Pharmacology
  • Toxicology

Background:

  • Clinical observations suggest adverse neurologic outcomes following methylene blue (MB) infusion during parathyroid surgery.
  • The potential neurotoxic effects of MB warrant thorough investigation.

Purpose of the Study:

  • To investigate the neurotoxic effects of methylene blue (MB) using in vivo and in vitro experimental models.
  • To evaluate the impact of MB on neuronal function, cell death, and dendritic structure.

Main Methods:

  • In vivo studies in rats assessed hemodynamic responses and isoflurane MAC after MB administration, with neuronal apoptosis evaluated via Fluoro-Jade B and caspase-3 staining.
  • In vitro studies utilized hippocampal slice cultures to measure excitatory field potentials and cell death, and neuronal cultures to assess dendritic arbor changes.

Main Results:

  • MB administration significantly reduced isoflurane MAC and induced widespread neuronal apoptosis in vivo.
  • In vitro, MB rapidly suppressed excitatory field potentials and caused dose-dependent cell death in hippocampal slices.
  • MB exposure, even at non-lethal concentrations, led to significant dendritic arbor retraction in neuronal cultures.

Conclusions:

  • Methylene blue exerts neurotoxic effects on the central nervous system.
  • The findings raise concerns about the safety of high-dose MB use in parathyroid surgery.

More Related Videos

Neurotoxicity Assessment in Adult Danio rerio using a Battery of Behavioral Tests in a Single Tank08:36

Neurotoxicity Assessment in Adult Danio rerio using a Battery of Behavioral Tests in a Single Tank

Published on: November 3, 2023

Related Concept Videos

Local Anesthetics: Adverse Effects01:12

Local Anesthetics: Adverse Effects

While local anesthetics are generally safe and well-tolerated, they can occasionally cause adverse effects that vary in severity. Local anesthetics can induce toxicity at two distinct levels. They can either produce local effects through direct contact with the neural elements or be absorbed into the bloodstream from the injection site, leading to systemic effects.
Once absorbed into the systemic circulation, local anesthetics can affect the organs that depend on the functioning of sodium...
Drugs Affecting Neurotransmitter Synthesis01:29

Drugs Affecting Neurotransmitter Synthesis

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, which converts...
Skeletal Muscle Relaxants: Adverse Effects01:21

Skeletal Muscle Relaxants: Adverse Effects

Skeletal muscle relaxants are widely used for muscle paralysis and relieving pain following any muscle injury or stiffness. However, depending on the drug type, they can have adverse effects that range from mild to severe. Usually, nondepolarizing neuromuscular blockers have minimal side effects. For example, drugs like d-tubocurarine, cisatracurium, and rocuronium cause hypotension, whereas drugs like baclofen, when stopped abruptly, can lead to the recurrence of spastic conditions.
Unlike...
Drug Toxicity: Dose-Dependent Reactions01:24

Drug Toxicity: Dose-Dependent Reactions

Drug toxicities can be stratified into pharmacological, pathological, or genotoxic based on their mechanisms. The incidence and severity of these toxicities generally increase with the drug's concentration in the body and exposure time.Pharmacological toxicity is evident when the therapeutic effects of drugs overshoot into adverse reactions in a predictable, dose-dependent manner. Central nervous system (CNS) depression from barbiturates is a classic example, with effects escalating from...
Toxic Reactions: Overview01:26

Toxic Reactions: Overview

When toxic substances penetrate the human body, they disseminate to various tissues, undergoing metabolic changes. This process yields reactive metabolites that may covalently bind with specific target molecules, resulting in toxicity.
Toxicity falls into two primary categories: local and systemic.
Local toxicity appears at the exposure site, such as protein denaturation caused by caustic substances.
In contrast, systemic toxicity requires the toxic agent's absorption and distribution,...
Drugs Affecting Neurotransmitter Release or Uptake01:21

Drugs Affecting Neurotransmitter Release or Uptake

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...