Consciousness-Altering Drugs Flashcards
What are the 4 groups of these drugs?
- depressants
- stimulants
- opiates
- hallucinogens
Depressants
- reduce nervous system activity resulting in a sense of relaxation and reduced anxiety
- includes: alcohol, barbiturates/benzodiazepines
Alcohol
- depresses area of brain that prevents inappropriate behavior
- increases dopamine levels
- generalized brain inhibition resulting in diminished arousal
What receptor has increased activity when consuming alcohol?
-GABA receptor – chloride channel that causes hyperpolarization of membrane
Alcohol Myopia
inability to recognize consequences of actions, creating a short-sighted view of the world
Wernicke-Korsakoff Syndrome
- caused by a deficiency of thiamine (vitamin B1)
- characterized by severe memory impairment with changes in mental status and loss of motor skills
Barbiturates/Benzodiazepines
- used as anxiety-reducing and sleep medications
- increase GABA activity, leading to relaxation
Stimulants
- cause increase in arousal in the nervous system
- increase frequency of APs
- includes: amphetamines, cocaine, ecstasy
Amphetamines
- cause increased arousal by increase release of dopamine, NE, and serotonin at the synapse and decreasing their reuptake
- leads to: reduction in appetite, decreased need for sleep, increased heart rate and BP, anxiety, delusions, euphoria, paranoia
- withdrawal causes depression, fatigue and irritability
Cocaine
- decreases reuptake of dopamine, NE, and serotonin
- similar intoxication and withdrawal effects as amphetamines
- has anesthetic and vasoconstrictive properties
- crack is the form of this that can be smoked
Ecstasy
- acts as a hallucinogen combined with an amphetamine
- causes increased heart rate and BP, blurry vision, sweating, nausea, and hyperthermia, increased alertness, feelings of euphoria
Opiates
- naturally occurring forms
- includes morphines and codeine
Opiods
- semisynthetic forms
- includes oxycodone, hydrocodone, and heroin
How do opioids/opiates work?
bind to opioid receptors in the PNS and CNS causing a decreased reaction to pain and a sense of euphoria
Heroin
- once injected the body rapidly metabolizes this to morphine
- typically smoked or injected
Hallucinogens
- exact mechanism is unknown but it is thought to be a complex interaction between various NTs especially serotonin
- causes distortions in reality and fantasy, enhancement of sensory experiences, increased heart rate and BP, dilation of pupils, sweating
Marijuana
- leaves and flowers of cannabis
- active chemical is THC
- THC acts at cannabinoid receptors, glycine receptors, and opioid receptors
- THC inhibits GABA activity and indirectly increases dopamine activity
- causes dry mouth, fatigue, impairment of short term memory, increased heart rate, increased appetite, lowered BP
- has similar psychological effects to stimulants, depressants, and hallucinogens
What brain pathway is drug addiction related to?
mesolimbic reward pathway (one of 4 dopaminergic pathways in the brain)
What brain structures are involved in the mesolimbic reward pathway?
- nucleus accumbens (NAc)
- ventral tegmental area (VTA)
- medical forebrain bundle (MFB) – the connection between the NAc and VTA
Mesolimbic Reward Pathway
- involved in motivation and emotional response
- addiction pathway that is activated by all substances that produce psychological dependence; also activated by gambling and falling in love
