ELM 10.1 Flashcards
Which of the following body areas contains a biological clock?
a. Liver b. Lungs c. SCN d. All of the above
d
Although the SCN is the “master clock”, many other body areas also contain biological clocks. This includes the lungs and the liver.
Why is oxaliplatin a landmark drug in “chronopharmacology”?
a. It corrects defects in the circadian cycle b. It was the first anticancer chronotherapeutic c. It was the first orexin receptor agonist licensed to promote wakefulness d. It was the first drug developed that removes the need for sleep in humans
b
Oxaliplatin was the first cancer chronodrug: during its development it was determined that giving it at at constant rate (as opposed to optimising the time of day it was administered) resulted in MUCH worse side effects. Optimising the time of delivery resulted in a 15% increase in the maximum tolerated dose.
The “master clock” in mammals is the:
a. Lateral geniculate nucleus b. Raphe nuclei c. Suprachiasmatic nucleus d. Thalamus
c
The SCN is the master clock in mammals. Circadian expression of clock genes within the SCN is what generates circadian rhythms in neuronal function.
Lithium is a first-line treatment for which psychiatric disorder?
a. Alzheimer's Disease b. Anxiety c. Bipolar disorder d. Major depressive disorder
c
Lithium is a member of a class of drugs known as mood stabilisers. It is used to treat bipolar disorder. Its mechanism is not fully understood but it appears to affect the expression of numerous circadian genes such as clock
Which of the following signalling molecules is synthesised from tryptophan?
a. Dopamine b. Melanopsin c. Melatonin d. Orexin
c
Melatonin, also known as “the sleep hormone” is produced in the pineal gland. Its precursor is tryptophan. Dopamine is produced from tyrosine. Orexin is a polypeptide signalling molecule that regulates arousal and appetite. Melanopsin is a visual pigment found in retinal ganglion cells
Biological clock cycles of approximately one day are known as:
a. Circadian b. Circannual c. Infradian d. Ultradian
a
Which stage(s) of sleep is/are also known as slow wave sleep?
a. NREM 1 and NREM 2 b. NREM 2 and NREM 3 c. NREM 3 and NREM 4 d. REM
c
NREM 3 and NREM 4 are slow wave sleep: a form of deep sleep, from which it is very difficult to wake. It tends to happen early in the sleep period.
A brain region involved in arousal and wakefulness is the:
a. Hippocampus b. Hypothalamic nuclei c. Locus coeruleus d. Putamen
c
The locus coeruleus is a small nucleus in the pons (brainstem). It is very important in arousal and wakefulness. This brain region is the main site in the brain from which noradrenergic neurons project. It is part of the reticular activating system. Lesions in this part of the brain can produce irreversible coma
A neuropeptide that regulates arousal and wakefulness is:
a. enkephalin b. melatonin c. neurotensin d. orexin
d
Orexin is produced in the hypothalamus which is where it gets its other name from: hypocretin. Neurons that produce orexin project to brain areas involved in wakefulness and stimulate them. A lack of orexin caused by autoimmune destruction of the neurons that produce it, is thought to be the cause of the most common form of narcolepsy in humans (See Bear et al., Chapter 19 Box 19.4).
