Neuro Tox

Question 1

What are common neurotoxic agents?

Answer 1

Methyl mercury, hexane, carbon disulfide, cocaine, amphetamines, domoic acid, MPTP, ethanol, lead, nicotine, organophosphates, botulinum toxin.

Question 2

What is the primary mechanism of methyl mercury neurotoxicity?

Answer 2

Disrupts neuronal microtubules, causing ataxia and sensory deficits.

Question 3

How does hexane cause neurotoxicity?

Answer 3

Metabolized to 2,5-hexanedione, forming pyrrole adducts, leading to axonal degeneration.

Question 4

What is the mechanism of cocaine-induced neurotoxicity?

Answer 4

Blocks dopamine reuptake, causing excitotoxicity and neuronal damage.

Question 5

How does domoic acid affect the nervous system?

Answer 5

Acts as a kainate receptor agonist, causing excitotoxicity and seizures.

Question 6

What biomarkers indicate neurotoxicity?

Answer 6

Nerve conduction velocity, CSF glutamate, tau protein, EEG abnormalities.

Question 7

What are standard testing methods for neurotoxicity?

Answer 7

Functional observational batteries (FOB), nerve conduction studies, maze tests, brain imaging.

Question 8

What are key endpoints of neurotoxicity?

Answer 8

Peripheral neuropathy, Parkinsonism, seizures, cognitive deficits, encephalopathy.

Question 9

How does carbon disulfide cause neurotoxicity?

Answer 9

Crosslinks neurofilaments, causing axonal swelling and peripheral neuropathy.

Question 10

What is the toxic effect of MPTP on the brain?

Answer 10

Metabolized to MPP+, causing oxidative stress and Parkinsonism in dopaminergic neurons.

Question 11

How does ethanol induce neurotoxicity?

Answer 11

Disrupts GABA and NMDA receptors, leading to cognitive deficits and fetal alcohol syndrome.

Question 12

What is the mechanism of lead-induced neurotoxicity?

Answer 12

Inhibits synaptic transmission and causes demyelination, leading to encephalopathy.

Question 13

What are clinical signs of organophosphate neurotoxicity?

Answer 13

Cholinergic crisis, tremors, seizures, respiratory failure.

Question 14

How does botulinum toxin cause neurotoxicity?

Answer 14

Inhibits acetylcholine release, causing flaccid paralysis.

Question 15

What is a key biomarker for methyl mercury poisoning?

Answer 15

Elevated mercury levels in hair or blood.

Question 16

How does acrylamide cause neurotoxicity?

Answer 16

Forms adducts with neurofilaments, causing distal axonopathy.

Question 17

What testing method detects neuronal excitability?

Answer 17

Electroencephalography (EEG) identifies seizure activity.

Question 18

How does trimethyltin affect the brain?

Answer 18

Damages hippocampus, causing memory loss and seizures.

Question 19

What is a long-term endpoint of lead exposure?

Answer 19

Neurodevelopmental deficits in children, including IQ reduction.

Question 20

What agent causes waltzing syndrome in rats?

Answer 20

IDPN (B,B’-iminodipropionitrile), due to neurofilament swelling.

Question 21

What is the role of nerve conduction studies in neurotoxicity?

Answer 21

Measures nerve impulse speed to detect peripheral neuropathy.

Question 22

What biomarker indicates excitotoxicity?

Answer 22

Elevated CSF glutamate levels.

Question 23

How does vincristine cause neurotoxicity?

Answer 23

Binds tubulin, disrupting microtubule formation, causing peripheral neuropathy.

Question 24

What is the mechanism of nicotine neurotoxicity?

Answer 24

Overstimulates nicotinic receptors, causing tremors and seizures.

Question 25

What test confirms organophosphate poisoning?

Answer 25

Cholinesterase activity assay shows reduced enzyme levels.

Question 26

How does manganese cause neurotoxicity?

Answer 26

Accumulates in basal ganglia, causing manganism, resembling Parkinson’s.

Question 27

What biomarker reflects axonal damage?

Answer 27

Elevated neurofilament light chain (NfL) in CSF.

Question 28

How does methanol cause neurotoxicity?

Answer 28

Metabolized to formic acid, causing optic neuropathy and blindness.

Question 29

What is an endpoint of chronic ethanol exposure?

Answer 29

Wernicke-Korsakoff syndrome due to thiamine deficiency.

Question 30

How does pyridinethione cause neurotoxicity?

Answer 30

Causes axonal swelling and degeneration, used in anti-dandruff shampoos.

Question 31

What test assesses cognitive function in neurotoxicity?

Answer 31

Morris water maze evaluates spatial learning and memory.

Question 32

How do amphetamines cause neurotoxicity?

Answer 32

Induce dopamine oxidation, causing oxidative stress and neuronal death.

Question 33

What biomarker monitors MPTP toxicity?

Answer 33

Reduced dopamine levels in striatum.

Question 34

How does hexachlorophene cause neurotoxicity?

Answer 34

Uncouples oxidative phosphorylation, causing intramyelinic edema.

Question 35

What is an endpoint of manganese exposure?

Answer 35

Manganism, with bradykinesia and rigidity.

Question 36

How does ammonia cause neurotoxicity?

Answer 36

Inhibits glutamate synthesis, causing hepatic encephalopathy.

Question 37

What test detects demyelination?

Answer 37

Magnetic resonance imaging (MRI) shows white matter lesions.

Question 38

How does domoic acid cause amnesic shellfish poisoning?

Answer 38

Excitotoxicity in hippocampus, leading to memory loss.

Question 39

What biomarker indicates lead encephalopathy?

Answer 39

Elevated CSF protein levels.

Question 40

How does carbon monoxide cause neurotoxicity?

Answer 40

Binds hemoglobin, causing hypoxia and basal ganglia damage.

Question 41

What is an endpoint of acrylamide exposure?

Answer 41

Distal sensory neuropathy with glove-and-stocking distribution.

Question 42

How does kainate cause neurotoxicity?

Answer 42

Overstimulates kainate receptors, causing dendritic injury.

Question 43

What test evaluates motor function in neurotoxicity?

Answer 43

Rotarod test assesses coordination and balance.

Question 44

How does metronidazole cause neurotoxicity?

Answer 44

Causes peripheral neuropathy via oxidative stress.

Question 45

What biomarker monitors organophosphate exposure?

Answer 45

Urinary dialkyl phosphates indicate recent exposure.

Question 46

How does tellurium cause neurotoxicity?

Answer 46

Inhibits squalene epoxidase, disrupting myelin synthesis.

Question 47

What is an endpoint of cocaine exposure?

Answer 47

Seizures and stroke due to vasoconstriction.

Question 48

How does fluoroacetate cause neurotoxicity?

Answer 48

Inhibits Krebs cycle, causing tonic convulsions.

Question 49

What biomarker indicates neuronal loss?

Answer 49

Elevated S100B protein in serum.

Question 50

How does strychnine cause neurotoxicity?

Answer 50

Inhibits glycine receptors, causing convulsions.