bio lecture 4 Flashcards
What do psychoactive drugs alter?
Brain function and behaviour by affecting neurotransmitter systems.
Name the categories of psychoactive drugs.
- Stimulants
- Depressants
- Opioids
- Hallucinogens
What are examples of stimulants?
- Cocaine
- Amphetamines
- Caffeine
- Nicotine
What are examples of depressants?
- Alcohol
- Benzodiazepines
What are examples of opioids?
- Heroin
- Morphine
What are examples of hallucinogens?
- LSD
- Psilocybin
What is the typical administration method for cocaine?
Typically snorted (powder) or smoked (crack).
What is the biological half-life of cocaine?
30-90 minutes.
What are the short-term effects of cocaine?
- Euphoria
- Energy
- Confidence
- Talkativeness
- Alertness
- Attention
How does cocaine affect neurotransmitter recycling?
Blocks reuptake channels, preventing monoamines from being recycled and keeping them in the synaptic cleft for longer.
What is the mechanism of action of cocaine?
Works at mono-aminergic synapses, blocking reuptake channels for monoamines.
What are the long-term effects of cocaine use?
- Neurotransmitter depletion leading to crash
- Increased tolerance to desired effects
- Sensitization to negative effects
What schizophrenia-like symptoms can cocaine cause?
- Hallucinations
- Paranoia
- Mood disturbances
- Repetitive behaviours
What physiological damage can cocaine cause?
- Destruction of nasal septum
- Sexual dysfunction
What is the legal status of cocaine in the UK?
Class A Drug: Up to 7 years for possession, life sentence for dealing.
What forms do amphetamines come in?
- Speed (D-amphetamine)
- Crystal Meth (Methamphetamine)
- Ecstasy (MDMA)
- Cathinone derivatives (Mephedrone, Methadrone, Methylone)
What are the short-term effects of amphetamines?
- Euphoria
- Confidence
- Talkativeness
- Alertness
What are the long-term effects of amphetamines?
- Hallucinations
- Paranoia
- Repetitive behaviors
What is the legal status of amphetamines and cathinones in the UK?
Class B: 5 years for possession, 14 years for dealing.
What is Ritalin (Methylphenidate) used for?
Used to treat ADHD.
What are the short-term effects of caffeine?
- Increases alertness
- Stimulates heart rate
- Shakes
- Constricts blood vessels
What is the biological half-life of caffeine?
3.5-5 hours.
What are the long-term effects of caffeine?
- Sleep deprivation
- Caffeine dependence
What is the mechanism of action of caffeine?
Blocks adenosine receptors.
What are the short-term effects of nicotine?
- Increases heart rate
- Reduces muscle tone
- Suppresses appetite
- Induces vomiting
What is the half-life of nicotine in chronic smokers?
~2 hours.
What are the long-term effects of nicotine?
- Tolerance develops quickly
- Contributes to cardiovascular disease
- Lung cancer
What is the legal status of nicotine in the UK?
Legal for adults (18+), banned for minors.
What are the short-term effects of alcohol?
- Euphoria
- Reduced anxiety
- Intoxication
- Memory impairment
What is the mechanism of action of alcohol?
- Agonist at GABA-A receptors
- Antagonist at NMDA receptors
What are the long-term effects of alcohol?
- Liver damage
- Brain damage
- Foetal alcohol syndrome
What is the legal status of alcohol in the UK?
Legal for 18+.
True or False: Stimulants increase CNS activity.
True.
Fill in the blank: Many drugs target the _______ reward system, leading to psychological addiction.
[dopamine]
What is the role of auto-receptors?
Bind the neurotransmitter and signal to the presynaptic terminal to reduce release.
What is the role of reuptake channels?
Pump the neurotransmitter into the presynaptic terminal for recycling.
