Stimulants caffeine Flashcards
how we we usually define stimulants
drug effects
what are the different ways we operationalize stimulants
biological= medical behavioural= psychological
a substance that raises levels of physiological or nervous activity (CNS) in the body.:T
biological/ medical definition of a stimulant
T: Chemicals that induce temporary improvements in mental/physical function
psychological / behavioural definition
what is the purpose of the biological definition
can be quantified by counts and limits
how is the biological definition paradoxical
suppressant enhances inhibition
T: Mimic/simulate activity of the sympathetic nervous
system
sympathomimetic
what are the 2 effects stimulants have on the CNS
- Physiological arousal of “fight or flight”
2. Parasympathetic suppression
what is an effect of the physiological arousal = sympa
alert and aroused = positive mood
what is an effect of the parasympathetic suppression suppression
• Anorectic effects (appetite suppressant)
the behavioural improvements to function mean improved accuracy
f faster and more if it
Behav: what determines the subjective effects of stimulants
determined by ranges, comparisons to baseline= fine line between arousal that causes happy mood vs panic
“Improvement” is dependant on … of behaviour
functionality
why don’t we opperationlize based on mood?
because fine line between happy and panic but this relates to function= Alert vs. Anxious
ambiguity in arousal. what is the effect of this
Ambiguity in attribution may allow for different interpretation
Behav: T: emotion is equivalent to the range of physiological arousal caused by external events
James Lange theory of emotion
Characteristics of stimulants: main 2?
speed accuracy trade off
state dependant memory
T: Memory retrieval is more efficient under similar
conditions to memory encoding
state dependant memory
T: how fast a task can be performed and how many mistakes are made in performing the task
speed accuracy tradeoff
what is the debate with state depedant memory
does it have to do with encoding, consolidation, retrieval, or all?
Formation of neuronal pathway is aversively affected with stimulant use on … what stage
state dependant memory (encoding)
in state department memory Consolidative mechanisms do not show selectivity due to …, what stage?
hyperactivation
consolidation
what in state department memory would this effect occur failure to get back to memory
retrieval
what behaviours does speed accuracy tradeoff aid vs lead to worse performance
new behaviour (don’t see tradeoff for learned behaviours)
T: faster you do something the worse you will preform
speed accuracy trade off
technical name of caffeine?
(Methyl)xanthines
T: methylxanthines Naturally found in plants and human body
alkaloid
what does it mean to say methylxanthines are organic- solvent soluble
solvent soluble, moderately water-soluble, bind to things you put in your latte
through an evolutionary lens why would caffeine be in plants
bi-directional relationship between plants and
humans= eat or be eaten!!
caffeine is Generally poisonous at larger amounts
yes
what are the metabolites of caffeine
theophylline and theobromine
what is the name of the chemical compound that then effects your body after caffeine and its metabolites act on body
paraxanthine
if protein powder says its caffeine free how do they still get you with caffeine
add theobromine or theophylline and the metabolites are active
why do you get such long lasting effects off caffeine
drug and metabolites both active
what are the 3 NT caffeine is structurally similar to
Structurally similar to Serotonin, Histamine, Dopamine
how does caffeines similarity to dopamine influence function
wanting
how does caffeines similarity to serotonin influence function
good mood
how does caffeines similarity to histamine influence function
sleep wake
T: A chemical used by a neuron to communicate to other neurons about their function
neuromodulator
neuromodulators acitvate neurons as well
f only communicate
2 things neuromodulators regulate?
gene expression and set points
what is the neuromodulator used in caffeine
adenosine
if neuromodulators don’t directly affect firing what 3 things do they do
formation look and activation of firing of other neurones
what kind of effect does adenosine have
inhibitory
what does adenosine do
saturates receptors and gives you tired feeling
where are the places adenosine communicates to and what does is effected there
brainstem =striatum = sleep wake cycle
what are the behavioural effects of adenosine effect on glutamate receptors
excitatory neurotransmitter that is released by nerve cells in the brain. It is responsible for sending signals between nerve cells, and under normal conditions it plays an important role in learning and memory= when your tired you are out of it
where are the 3 areas adenosine has its inhibitory effects
sleep/ arousal
cognition/ memory/ learning
everywhere else in body
why can’t you learn while you’re tired
dopamine system needed to code for reward can’t act with adenosine sitting on it
what brain area and what receptor does adenosine inhibit to hinder cognition memory and learning
– hippocampus
– Dopamine Antagonist
caffeine is excitatory
f its antagonizing an antagonist= why you feel fake up
what are the adenosine receptors
A1, A2, A2a, A3
what is the Adenosine (A1) receptor associated with
Slowing metabolic function
A1 what are the behavioural effects of adenosine Slowing metabolic function
it is priority everything else stops = sleep while driving
A1 T: Retrograde messenger in the synapse that has to do with building receptor channels on membrane
NMDA
A1 what does adenosine do to NMDA
Postsynaptic depression of NMDA* receptor= stop building other receptor channels
A1 what does NMDA facilitate 2
memory, synaptic plasticity (hebbian learning)
A1 what does Caffeine dot NMDA
it keeps going
A1 what does caffeine do to metabolic system
keeps it going
A1 Caffeine facilitates memory and synaptic plasticity
t .. TOO A POINT!
A1 Hyper activation results in …
inability to focus – “jitters”= James Lange
A1 caffeine causes migranes
f adenosine does caffine alleviates them by opening vasculature
A1 & A2a responsible for 2
O2 in blood especially to brain
Reducing heart rate
why does caffeine be used in o2 deficit infant
gets O2 flowing to the brain
…2 used to avoid hypoxia (stimulate respiration)
caffeine and theophylline
why is taking coffee after your meds a bad idea
caffeine limits permeability of blood brain barrier
adenosine closes the blood brain barrier
f Opening the blood-brain barrier
where are A3 receptors and what do they do
on cancerous skin cells Can be used to inhibit melanoma cells= collapse with adenosine antagonism
what does caffeines effects on A3 cells effect
interfere with destruction of cancer cells
T: adenosine receptor used as a Anti-inflammatory agent
A2a
so what does caffeine on A2a do
Caffeine would thus allow inflammation, however it also directly promotes inflammation reduction
caffeine and … plants are cousin plants
cocaine
can you get addicted to cocaine 3 reasons
yes system begins to tolerate chemical
dopaminergic system
adrenaline= attention arousal
2 main behavioural effects of coffee
mood elation or performance enhancement
can makes you feel happy and alert because of dopamine
f dopamine makes you feel rewarded not happy
why does cafe increase mood
reward feels good and placebo feel better by comparison
does caffeine actually improve performance
yes and no
when does caffeine enhance performance
boring and simple tasks where you otherwise would have quit decreases fatigue (still = tired)
when does caffeine inhibit performance
disruptive in
complex tasks= frustrated
physical tasks
e.g. which finger to move? learning pattern and moving fast but not correctly
physical taks
difference between fatigue and tired
tired is feeling fatigue is observable
if you are still =ly tired on caffeine why do people use it
still =ly tired (brain not moving as fast) just don’t feel as bad about it
does caffeine have a sobering effect?
no still intoxicated and in fact stressing system out more
Absorption and Elimination is constant amount people and amounts
f highly variable and dose dependant
what are the 2 weird things in how different doses influence people
developmental stage
time to peak
how does time to peak change across doses
it doesn’t ! should though if you think of saturation
how does caffeine influence kids vs adults
children need more due to different function of adenosine
why Time to peak does not change across doses
don’t know
what is the absorption and elimination of caffeine like
highly variable
2 things absorb and elimination of caffeine relies on
experience and dose dependance
more experience with caffeine results in shorter elimination and absorption time
f results in longer times
how does smoking cigarettes change caffeine absorption and elimination
more caffeine results in slower absorption and metabolism
due to the dose dependant responses in caffeine time to peak changes between doses
f always same
why does caffeine time to peak in blood not change
gated/ binding mechanism of caffeine
dose dependance: what makes the concentration levels and time of caffeine decrease
presence of other sugars
do smokers eliminate coffee faster or slower
faster
do you get tolerance and withdrawal with caffeine
for physiological effects yes but not psychological ones
4 problems that confuse our understanding of tolerance and withdrawl mechanisms in caffeine ?
– variability of absorption (sugar metabolism)
– poor operationalization of dosage (how much is too much?) – individual differences
• behavioural tolerance, patterns of use – small rates (11%)
do you need to consume large amounts of caffeine to have withdrawal
no
4 criteria for caffeine use disorder
tolerance
withdrawl
desire to quit/ control use
continued use
are there consistent patterns of withdrawl and compulsion in caffeine
no
is caffeine safe
according to FDA yes!
how many grams per day would you need for it to be toxic
10
how many cups of coffee is toxic = 10 grams
57
energy drinks are a combination of
xanthine and potentiators (enhance sensitization)
if an energy drink is advertised as low caffeine is it ?
might have Highly variable in Xanthine content
in energy drinks: Caffeine is listed only if added (but not …
naturally occurring
3 things that are not measured in energy drinks
metabolites, precursors, compounds
in energy drinks: Panax Ginseng Root (…), Guarana Seed (….)
potentiator
xanthines
how do you compare the potencies of energy drinks
you can’t
2 timing effects of energy drinks
kindling and excitoxicity
T: neurons are damaged and killed by the overactivations of receptors for the excitatory neurotransmitter glutamate
excitotoxicity
taurine in energy drinks is similar to … what NT
GABA
how does GABA act differently in kids and adults
(GABA) Inhibitory neurotransmitter in adults/Excitatory in children
3 problems with adding taurine to drinks
excitotoxicity, dosage, developmental effects
T: drug used to reduce anxiety
anxiolytics
what has anxiolytic effects
Taurine
what’s the problem with the anxiolytic effects of taurine
boycotts natural warning mechanism
the similarity of taurine to gaba can have what effect on memory
antero/retrograde amnesia
problem with amnesia caused by taurine
boycotts learning mechanism
what does GABA do to memory
can’t remember things
what does it mean to say taurine is a neuroprotectant (how can it be protective)
• Inhibit glutamate-induced exitotoxicity= inhibitor in schizoids and mania
the fact that taurine is a Trophic & inhibitory modulator contributes to its … properties
neuroprotectant
Altered in neuropsychiatric disorders
??
why is it neuroprotective that taurine is a antioxidant
prevent oxidative stress
what happens when you combine caffeine and taurine
synergistic effect = caffeine effects potentiated
with the synergistic effects of taurine and caffeine what happens to performance
Accuracy vs. RT (bad performance believe doing really well)
with the synergistic effects of taurine and caffeine what happens to heart rate
“aerobic” heart pattern= stress factor
with the synergistic effects of taurine and caffeine what happens to mood
increase it Feeling less ill/negative
with the synergistic effects of taurine and caffeine decreased pain tolerance
t
