Lecture 4 Flashcards
the arousal system is made of neurons that release which neurotransmitters
- acetylcholine
- histamine
- dopamine
- norepinephrine
- serotonin
increasing firing of the neurons or the synaptic levels of the neurotransmitters will promote (related to sleep)
wakefulness
decreasing firing of the neurons or the synaptic levels of the neurotransmitters will promote
sleep
when the arousal system is firing
the sleep center is not firing
the arousal system is activated by
hunger signals and sunlight
- particularly blue light
during the day the brain uses energy in the form of ATP and waste product is
adenosine
sleep is promoted by
adenosine
- accumulates when the brain is awake and is cleared when the brain is asleep
what is attention
selection of information for focused conscious processing
- required for most forms of cognition
important parts of the brain for attention include the
cortex, basal ganglia, thalamus
attention requires a certain level of arousal, which is determined by
neurons in the reticular activating system
what is the reticular activating system
determines where we are on the spectrum of wakefulness
for simple tasks, the more awake you are
the better you will perform at this task (linear relationship)
for complex tasks what does the curve look like
resembles a bell curve, meaning the more awake you are to a certain point the better you will do
- if you are too aroused you will perform worse (panic)
norepinephrine neurons are located close to
dopamine neurons in the mid brain and send their axons throughout the cortex
t/f norepinephrine neurons have a repuptake mechanism
true, known as the norepinephrine transporter (NET)
another name for norepinephrine
noradrenaline
what are psychostimulants
drugs that promote wakefulness and attention
- often increase motor activity as well
t/f caffeine is not a psychostimulant
false, it very much is
how does caffeine act
It acts by blocking the adenosine receptor in the brain. This prevents the adenosine signal that triggers sleep. It also indirectly promotes signaling from adrenaline and norepinephrine because it amplifies the signal from those transmitters.
- is an antagonist of the adenosine receptor
is caffeine addictive
no it is not, but people do develop dependence and tolerance to its effects
adverse effects of caffeine
dry mouth, agitation, nausea/heartburn, diarrhea, insomnia, racing heart
have fatal overdoses of caffeine happened
yes, rare but they have happened
what are the two ways caffeine increase vigilance
- antagonist of the adenosine receptor
- inhibitor of phosphodiesterase enzyme
explain how caffeine is an antagonist of the adenosine receptor
- Adenosine is the byproduct of metabolic activity in the brain – when neurons fire they consume ATP (energy) and it is converted to adenosine.
- Adenosine binds to the adenosine receptor to induce sleepiness. Blocking the adenosine receptor prevents the signal to induce sleep.