Cognitive enhancers Flashcards
nootropic drugs
enhance cognition in healthy brains
Can drugs increase IQ?
No, but they can improve attention
What NTs are involved in the arousal system, i.e. promoting activity of which NTs promotes wakefulness?
Acetylcholine, histamine, NE, 5 HT, orexin
HANSO
reticular formation
arousal system
which NT promotes sleep
adenosine
- accumulates when brain is awake (from ATP use) and clears during sleep
What does the viPOA (slow-wave-sleep-on) region inhibit?
viPOA inhibits:
- the arousal system (and vice versa the arousal system inhibits the viPOA)
- orexinergic neurons in the LH
What signals modulate the LH orexinergic neurons?
biological clock (time of day, light) - activates
hunger signals - activate
satiety signals - inhibit
orexin
Regulates arousal and hunger
Psychostimulants
drugs that promote wakefulness and attention
- often increase motor activity as well (undesired)
what kind of drug is caffeine
psychostimulant
how does caffeine work
- blocks adenosine receptor which stops adenosine from signalling that you’re sleepy
- also inhibits phosphodiesterase which indirectly increases NE and E
Phosphodiesterase
enzyme that breaks down cAMP
- inhibited by caffeine
Why are NE and E signalling levels increased with caffeine intake
NE and E act through Galpha-s protein which increases cAMP (when they bind to their receptors, cAMP is increased)
- preventing breakdown of cAMP by inhibiting phosphodiesterase works in same direction as NE and E (more cAMP) so their signal is amplified
dependence vs addiction
dependence: body performs best with the drug, would prefer to have it
addiction: compulsion to take drug despite adverse consequences
caffeine adverse effects
dry mouth, heart burn, agitation, nausea, diarrhea, insomnia, racing heart
- a lot of these similar to adrenaline because cAMP (dry mouth, rapid HR)
fatal doses rare but have happened (cardiac arrest)
What happens during slow wave sleep
brain increases pumping of fluid - metabolites washed away
Most psychostimulants are…
DAT and NET blockers
- ex. cocaine, methamphetamine, amphetamine, and methylphenidate
adderall vs ritalin
adderall = amphetamine
ritalin = methylphenidate
are psychostimulants addictive?
they can be:
cocaine is a psychostimulant and so is meth, but something like ritalin (methylphenidate) isn’t.
Depends on the route of admin and dose (also is individual variation though)
Effects of psychostimulants
wakefulness, euphoria, suppressed appetite, insomnia, agitation, restlessness, dry mouth, racing heart, GI upset, constipation, grandiosity, paranoia, psychosis
Dopamine recycling:
- normal
- on cocaine
- on amphetamine
bonus: which drugs act same way as last two on DAT?
normal
- VMAT (vesicular monoamine transporter) packages DA
- DAT takes up DA from synapse to be repackaged
cocaine
- DAT is plugged so DA is accumulated in synapse and activates more DRs
Amphetamine
- reverses the DAT, DA from cytosol actually goes into synapse
- amphetamine also displaces DA from the vesicles which pushes DA into cytosol (this flips the conc gradient and allows VMAT to reverse)
BONUS: methylphenidate does same as cocaine and plugs DAT, methamphetamine does same as amphet
drugs like amphet, cocaine, methylphen act on which transporter(s)?
mostly act on DAT but also do the same thing to SERT and NET, just to a lesser extent
Neuropathology of Alzheimer’s Disease (AD)
- amyloid plaques and neurofibrillary tangles are clearly visible in microscopy
- gross diffuse atrophy of brain and loss of neurons, neuronal processes, synapses
- degeneration in temporal and parietal lobes, as well as part of frontal cortex
Which NT reduced in AD? Elevated?
Acetylcholine is reduced as well as 5HT and NE
glutamate usually elevated
