Lec #5 Drugs for Attention

Question 1

what brain region determines our state of arousal

Answer 1

reticular activating system (RAS) sets the arousal by releasing the neurotransmitters norepinephrine and acetylcholine (the more neurons, the more arousal)

Question 2

what are the 5 pro-vigilance neurons that help keep us awake and alert?

Answer 2

• histamine
• dopamine
• norepinephrine
• acetylcholine
• serotonin

Question 3

According to Yerkes and Dodson, what level of arousal is needed to solve difficult problems?

Answer 3

moderate level of arousal

Question 4

norepinephrine (or noradrenaline)

Answer 4

neurotransmitter that is associated with a high arousal state, which means increased attention and focus, but also increased fear and anxiety

Question 5

what are the receptors of norepinephrine (NE)?

Answer 5

• adrenergic receptors= G-protein coupled receptors
• increase of neuron activity, despite GPCRs are able to increase or decrease

Question 6

phosphodiesterase

Answer 6

enzyme responsible for breaking down cAMP and cGMP into their inactive forms

Question 7

adrenergic receptors

Answer 7

When norepinephrine binds to adrenergic receptors, it causes the production of a signal called cyclic AMP.
- Cyclic AMP is degraded by phosphodiesterase enzyme.
- Caffeine antagonizes the enzyme that degrades the cAMP, amplifying the signal from norepinephrine.
- This is also why caffeine causes similar symptoms to adrenaline (dry mouth, rapid heart rate).

Question 8

what happens during a crisis when adrenaline is released into the bloodstream and body experiences a fight-or-flight response?

Answer 8

• increased heart rate
• sweating
• pale skin
• increased NE neurons promoting attention and quick response

Question 9

what receptors do norepinephrine and dopamine activate?

Answer 9

GPCRs (dopamine receptors), firing more neurons

Question 10

Acetylcholine

Answer 10

neurotransmitter that is associated with learning and memory, and the death of these neurons is thought to contribute to Alzheimer’s dementia.

Question 11

what are the two receptors activated by acetylcholine? (can have both excitatory and inhibitory effects)

Answer 11

• nicotinic receptors= sodium ion channels
• muscarinic receptors= G-protein coupled receptors (adrenergic receptors)

Question 12

histamine

Answer 12

• produced as a neurotransmitter in a small number of neurons with a powerful effect
• active when the brain is awake and inactive during sleep
• drugs that block histamine make you sleepy

Question 13

orexin

Answer 13

neurotransmitter released as a hunger signal, low blood sugar and promote arousal and vigilance needed to obtain food

Question 14

2 drugs used to increase attention and vigilance through increasing the levels of dopamine and norepinephrine

Answer 14

• amphetamine
• methylphenidate

Question 15

what are the dopamine transporters making up the recycling mechanism of neurotransmitters stored in synaptic vesicles?

Answer 15

DAT and NET

Question 16

what are the similarities between amphetamine and methylphenidate?

Answer 16

• both bind to the dopamine transporter (aka DAT) and the norepinephrine transporter (aka NET)
• used to treat attention-deficit/hyperactivity disorders at low-doses
• reduce appetite and cause sleep difficulties due to an increase in dopamine and

Question 17

what are the 3 drugs that increase vigilance and performance on tasks that require high levels of arousal? (“smart drugs” that can be addictive)

Answer 17

• Amphetamine (Adderall)
• methylphenidate (Ritalin)
• modafinil (Provigil)

Question 18

methylphenidate (ritalin)

Answer 18

• blocks the DAT and NET by creating an accumulation of dopamine and norepinephrine
• similar structures and effects to cocaine but has a lower off-set
• prescribed at doses that do not elevate dopamine to a level where it is addictive

Question 19

amphetamine (Adderall)

Answer 19

• DAT and NET reverser
• dopamine and norepinephrine transporter reverser into the synapse instead of clearing it out. Like methylphenidate, it is formulated for slow-release and at low doses to reduce abuse potential.

Question 20

what drug is used to treaty narcolepsy= disorder where the normal switch between sleep and wakefulness is not maintained

Answer 20

modafinil
- taken during the day to promote wakefulness
- inhibits the DAT and NET

Question 21

adenosine

Answer 21

• a 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 from inducing sleep.

Question 22

what are the 2 components sleep promoted by?

Answer 22

adenosine and satiety signals

Question 23

what are the 2 components the arousal system is activated by?

Answer 23

hunger signals and sunlight

Question 24

circadian rhythm

Answer 24

acts as the body’s internal clock, regulating the timing of sleep and wakefulness by responding to external cues, primarily light and darkness. It helps coordinate the release of hormones, such as melatonin and cortisol, that influence alertness and sleepiness.

Question 25

how is caffeine a psychostimulant?

Answer 25

• antagonist of the adenosine receptor
• prevents adenosine signal that triggers sleep
• indirectly promotes signaling from adrenaline and norepinephrine

Question 26

what are the adverse of caffeine, non-addictive?

Answer 26

• potential to develop dependence and tolerance
• dry mouth
• agitation
• nausea/ heartburn

Question 27

what are the 2 actions of caffeine that increase alertness?

Answer 27

• antagonism of adenosine receptor
• inhibitor of phosphodiesterase enzyme

Question 28

what are the cocaine effects on dopamine recycling?

Answer 28

• inhibits the reuptake of dopamine by binding to the dopamine transporter (DAT) proteins on the presynaptic neurons.
• increase in dopamine levels in the synapse.

Question 29

What are the adverse effects of psychostimulants cocaine and amphetamine?

Answer 29

• loss of appetite
• insomnia

Question 30

what are the amphetamine effects on dopamine recycling?

Answer 30

• cause presynaptic neurons to release large amounts of dopamine into the synapse
• occurs through a complex mechanism involving amphetamines’ ability to enter the presynaptic neuron and disrupt the normal regulation of dopamine release.
• inhibit the reuptake of dopamine to some extent, but their primary mechanism is increasing the release of dopamine.

Question 31

what drugs are used to treat attention deficit orders?

Answer 31

psychostimulants to dopamine/ adrenaline neurotransmitters and cause the neurotransmitter to be reverse-transported into the synapse