Psychostimulants Flashcards
What are psychomometics
Lsd, mescaline, psilocybin, cannabinoids
Induce temporary states of altered perception
Symptoms similar to psychosis
Clearly percieved, vivid and subjective experiences
Control diminished
What are psychomotor stimulants?
Amphetamine, cocaine, mdma, caffeine Increase behavioural and motor activity Increase in alertness and disruption of sleep Pupil dilation Increase body temp Anxiety, insomnia, irritability
Nikethamide
Respiratory stimulant acting directly in the respiratory centred of the brain
Oxilofrine
Another stimulant used by atheletes
What is caffeine metabolised into?
Paraxanthine, increases lipolysis leading to elevated glycerol and ffas in blood plasma
Theobromine, dilates blood vessels, increases urine volume
Theophyline, relaxes smooth muscles in the bronchi
How does caffeine work?
Similar in structure to adenosine
Acts as an antagonist on a2a gs and a1 gi receptors
Role of a1 receptors
Presynaptic neurones mediate the inhibition exerted by adenosine on the release of nt (including glutamate, da and ach)
This is thought to account for positive effect produced by caffeine on arousal, vigilance and attention
Where are adenosine receptors found?
Neocortex, amygdala, substantia nigra, nuc tractus solitarus, sc, cerebellum, hippo, thal
Role of nicotine
Acts on presynaptic nicotinergic cholinergic receptors
Releases da, na, ach, glutamate, 5ht, beta-endorphin, gaba
Pleasure, appetite suppression, arousal, cog enhance, memory enhanc
Strychnine
In small doses improves visual and auditory acuity.
Larger doses violent extensor spasms and convulsions
Eventually death by asphyxia
Blocks receptors for glycine, no cl- increase postsynaptic neuron
Amphetamine
Release of da and na from presynaptic storage sites
Binds to presynaptic membrane of da neurones
Changes ph, leading to da containing vesicles releasing contents into cleft
