Topic 4- Stimulants and alohol

stimulents and aclhoh

-            Cocaine

-            (Amphetamines)

-            Caffeine

-            Nicotine

-            Alcohol

cocaine

-            Typically snorted in powder form or smoked in its free-base form (crack)

-            Reaches peak in blood at 30-60 min- snort

-            Easily penetrates the blood-brain barrier – lipophilic molecule

-            Biological Half-Life: 30-90 minutes- more quicliy if regular user

when dose cocain recah half life

            Reaches peak in blood at 30-60 min- snort

-            Biological Half-Life: 30-90 minutes- more quicliy if regular user

short etrm effects of coke

•        Cocaine is a stimulant, it increases:

•        Euphoria

•        Energy

•        Confidence

•        Talkativeness

•        Activity

•        Alertness

•        Attention

Action of Cocaine at Mono-aminergic Synapses

Any snapsis that use monoamines synapsis

Monamines are senertionin dopime and nerodreadlin

Also have reuptake chanles – a way for the presynaptic chanle to recycle and put back inro vesicals

-            Reduces nerotransmitters in the clesft

-            Rcycles and reuses

Coke blacks the reuptake chanles- nerotrasmitters dsonst get recycles so stays in clef  and has higher concentarrtion

so it keeps it there for longer

activity at neroadrenergic synaps supress

arousal and plato

monoemgic sysnas

• seritoninn

• dopimine

• neroadrmilin

Sympathetic Nervous System

used by the sypathatic nerous system- narro the blood vesivals so cant be dilated so they cant go to the peinous/ clit

coke can cause sexual dysfunctio

Cocaine Long-Term Effects

•        The lack of reuptake results in depletion of monoamines (serotonin, noradrenaline,…)

ð  “crash” into depression after several hours

•        The concentration of nerotransmitters in the presynaptic because of the lack of reuptaking witch causes crashes/ binges so takes a long time recovery

•        This is usually remedied by taking more cocaine.

ð  2-3 day cocaine “binges”

•        Destruction of the nasal septum- regular user

•        Causes vaisal constriction highest concentration is in the nose – not enough oxygen, no glucus- so the ceels start dying

•        Schizophrenia-like symptom:

ð  Hallucinations

ð  Delusions of Persecution

ð  Mood Disturbances

ð  Repetitive Behaviours

•        Sexual dysfunction

•        Tolerance for some of the “desired” effects, such as euphoria, confidence

Sensitisation for other effects, such as convulsiveness, stereotyped behaviour, addictiveness getting bad effect eler in the dosage

coke addictivennes

•        Direct effect on Dopamine released in the N. Accumbens and Prefrontal Cortex

•        Therefore Direct activation of the “seeking” or “reward” pathway

•        Strong “psychological” addictiveness, much less physical addictiveness

Dopine is part to the addict8ivness not the positive side effects more likely the nerodarenalin

Action of Amphetamines at Mono-aminergic Synapses

work on same synapsis and reuptake channles as cokain

• slightly diffrent properties on how they affect the diffren monamines and synapsis

• they revers the uptake chenles

• push the NT out of the reuptake dont need action potental

ritalin (methylyphendate)

• acts simmilarliy to come by blocking the monoamine reuptake trasbporte

• the relice is much more gradua

• dose nit have the sme immidate effcets as coke

• effcetive tratmet to ADHD

Caffeine

•        Typically ingested in coffee or soft drinks

•        Concentration peaks after ~40 minutes

•        Easily passes through the blood-brain barrier

•        Biological Half-Life: 3.5-5 hours (longer in children)

•        Lethal dose: 100 cups of coffee (10g of caffeine)

Caffeine’s Short-Term effects

•        Psychostimulant:

•        Increases alertness and wakefulness

•        Induces clear thinking

•        Induces restlessness

•        Difficulty with fine movements

•        Increases cardiac contractions

Constricts blood vessels

Caffeine’s Side effects

•        Anxiety

•        Insomnia

•        Change in mood

•        Hypertension

•        High blood pressure make worse

Caffeine Physiological Action

•        Blocks adenosine receptors

•        Adenosine is involved in inducing sleep

•        vasodilation- signial in the blood vecies- bllod vescle contract= higher blood pressure

-            Stimulates adrenaline release from adrenal medulla

Caffeine Long-term effects

mostly slep deprivation

some of it effects can be counterd by using more cafine to wake up in the moreing

Caffeine Addictiveness

•        Clear physical dependence.  Withdrawal symptoms include:

•        Headaches (vasodilation)

•        Sleepiness

•        Irritability

•        Difficulty concentrating

•        Psychological dependence: it increases dopamine release in the n. Accumbens

nictine

•        From the tobacco leaf:

•        Typically smoked or vaped – tyaked by lungs

•        Sometimes chewed

•        Within 7 sec of a puff, 25% of the nicotine in the smoke has already crossed the blood-brain barrier!

Biological Half-Life of 2 hours in the chronic smoker

Nicotine Short Term effects

•        Induces vomiting- affcet the brain stem area thet induces noausia

•        Reduces muscle tone (relaxes)

•        Reduces weight gain

Increases heart rate and blood pressure

Nicotine Physiological Action

•        Binds to nicotinic Acetylcholine receptors

agonist at the synapsis

symils parsypthetic and sypathetic

sympathetic wins- stronger tone

•        Nicotinic receptors are involved in stimulation of sympathetic nervous system, including release of adrenaline from the adrenal gland

Nicotinic receptors are also found in the brain

Nicotine Long-term effects

•        Body easily develops tolerance

•        Possibly wears out the heart more quickly

•        Major problems are from other components of tobacco (and cigarette smoke), which can cause cancer, cardiovascular disease, ect

•        Long term consequences of smoking in in the smoke rather than the nicotine- however there isn’t much LT consequences to the nicotine and vaping

Nicotine Addictiveness

•        A large component of physical dependence: Withdrawal symptoms include:

•        Craving

•        Irritability

•        Increased appetite

•        Insomnia

•        Although controversial, possibly the most addictive drug from a psychological point of view (effect on dopamine in n. Accumbens)

nictine of dopimine- nucals sucumbas

From the physical aspects are strong

Debate about the psychological addiction

Harder to self administer coke than nicotine- rats

Humans- highly addictive 70% addicted to smokers , 30% who do heroine – relaps within a year

Easy to relaps

Alcohol

•        Usually ingested (mostly as drinks)

•        Reaches max. blood concentration in 30-90 minutes

•        Easily crosses the blood-brain barrier (soluble in both water and lipids)

•        Mostly eliminated through the liver, which breaks it down at a steady rate

•        Half life depends on the molecule

Alcohol Short Term effects

•        Low dose

•        Mild euphoria

•        Anxiolytic effect (lowers anxiety)

•        Higher dose: intoxication

•        Slower reflexes

•        Incoordination

•        Sedation

•        Memory problems

•        Dilation of blood vessels (heat loss)- acholo coat

•        Diuretic (more urination)

Alcohol Physiological Action

•        Agonist of GABA-A receptors (increases inhibitory processes)- mimic/ increase effect of GABA( inhinitory system)

controls behvior

•        Antagonist of NMDA (group of glutamate receprtes) receptors (suppresses excitatory processes)- involved in meoemary formation- blocking prevents the making of meoemoys meomemory loss long term

•        And several other effects…

•        Intracts with lots of different things

Alcohol Long-term effects

•        Cirrhosis of the liver: liver failure

•        Brain damage (especially hippocampus: Korsakoff’s syndrome)- perminalt cant make LTM

•        Foetal alcohol syndrome- when pregnant

Alcohol Addictiveness: Pysical dependace

•        Tolerance is induced even from one night drinking and results in mild withdrawal symptoms (hangover)

•        After chronic use, there are very strong withdrawal symptoms (Delirium Tremens); this can be fatal- delirous tremmer- go into seasures

the bodys mechnisusm for getting back to homeostatus for gabab a- goes down so the body make not enoug Gaba making the circtes not be able to be inhabitted causing seasures

Alcohol addictivenss:Psychological dependence:

•        It increases dopamine release in the n. Accumbens (as do other NMDA receptor antagonists)

•        Strong heritable component to alcoholism