Chapter 8 Drugs And Hormones Flashcards
Psychopharmacology
The study of how drugs affect the nervous system and behaviour.
Drugs
Chemical compounds administered to bring desired change in the body
Psychoactive drugs
Substances that act to alter mood, thought, or behaviour and are used to manage neuropsychological illness
Route of administration
The way in which a drug enters and passes through the body to reach its target
Which is the most complex route for a drug to reach its target?
Oral administration
Weak acids in the stomach
Are readily absorbed
Weak base in the stomach
Must pass through the stomach & into the intestine
What properties must a drug have in order to travel through the bloodstream
-Must be hydrophilic -It’s molecules must be small enough to pass through the pores of capillaries (vessels that carry blood to cells)
How much of a drug is reduced if each obstacle to the brain is eliminated
The amount of the drug needed is reduced by a factor of 10
Blood brain barrier (BBB)
Made of capillaries that have tight junctions formed by endothelial cells. Prevents drugs from entering the brain easily.
The three brain regions that lack a blood-brain barrier
Pineal gland, pituitary gland, and the area postrema
Lack of BBB in pituitary gland
Allows secretion of hormones into blood system. Allows other hormones to enter the pituitary (this causes the pituitary to secret hormones)
Lack of BBB in the area postrema
Allows toxic substances in the blood to trigger vomiting
Lack of BBB in pineal gland
Enables hormones to reach it and modulate the day-night cycles
2 ways vital substances (oxygen, CO2, waste) cross the BBB
1) Small molecules(CO2, O) are not ionized = fat soluble. Therefore, they can pass through the endothelial membrane 2) molecules of food components (glucose, amino acids) are transported by specialized proteins (pumps, active transport systems)
How does the body eliminate drugs
Through dilution and catabolic process
Catabolic process
The breakdown of chemical compounds
The seven major steps in neurotransmission that a drug can affect in a synapse. Pg 242
1) synthesis 2) storage 3) release 4) receptor interaction 5) inactivation 6) reuptake 7) degradation
2 ways a drug can influence synaptic function
1) agonists 2) antagonists
Agonists
Drugs that increase the effectiveness of neurotransmission. Ex. Black widow spider venom promotes excess release of acetylcholine (ACh) = paralysis
Antagonists
Drugs that decrease the effectiveness of neurotransmission. Ex. Botulin toxin blocks release of ACh = paralysis. Used to stop spasms.
Organophosphates
Class of compounds that bind irreversibly to acetylcholinesterase. Are extremely toxic.
Tolerance
A decrease response to a drug over time. Develops with repeated used
3 types of tolerance
1) metabolic tolerance 2) cellular tolerance 3) learned tolerance
Metabolic tolerance
Increase in enzymes needed to breakdown (ex.) alcohol. Therefore, alcohol is metabolized quicker and blood alcohol levels are reduced
Cellular tolerance
Activities of brain cells adjust to minimize the effects of ex. Alcohol present in the blood. May explain why people don’t appear drunk even though they have high blood-alcohol levels
Learned tolerance
People learn to cope with daily demands of living while under the influence of alcohol.
Sensitization
Increased responsiveness to a drug. Develops with occasional use (not used repeatedly)
Classification of psychoactive drugs is based on…
The most pronounced behavioural or psychoactive effect produced by a drug
Seven class of psychoactive drug classifications
1) antianxiety agents and sedative hypnotics 2) antipsychotic agents 3) antidepressants 4) mood stabilizers 5) opioid analgesics 6) psychomotor stimulants 7) psychedelic and hallucinogenic stimulants
Antianxiety agents
Drugs that reduce anxiety; minor tranquilizers such as benzodiazepines and sedative-hypnotic agents. Valium is widely prescribed. Can produce cross tolerance. Harder to overdose
Sedative Hypnotics
Drugs that reduce anxiety; alcohol and barbiturates. Can produce a tolerance after repeated use. Easy overdose
Benzodiazepines
Used for coping with major life streamers like a traumatic accident or death. Also a presurgical relaxation agent
Barbiturates
A drug mainly used for anesthesia. Can induce sleep, anesthesia, & comas
Cross tolerance
When the tolerance developed for one drug is carried over to a different member of the drug group
Main target for antianxiety and sedative-hypnotic drugs
Receptor sites for GABA (major inhibitory neurotransmitter)
The 3 binding sites of GABA(a)
1) sedative-hypnotic site 2) GABA site 3) antianxiety site Each site is located on the GABA receptor.
Fetal alcohol syndrome (FAS)
Pattern of physical malformation and mental retardation
Dissociative anaesthetics
Group of sedative hypnotics developed as anesthetic agents; produce altered states of consciousness and hallucinations and impairs memory for recent events; “date-rape” drug
Psychosis
Neuropsychological conditions characterized by hallucinations or delusions. Ex. Schizophrenia
Major tranquilizers (neuroleptic)
Antipsychotic drugs that blocks the D2 (dopamine) receptor; mainly used on schizophrenics
Dopamine hypothesis of schizophrenia (pg 251)
Schizophrenia symptoms are due to excess activity of the neurotransmitter dopamine
Amphetamines
Increase dopamine activity; cause schizophrenia like symptoms. Also blocks the reuptake of dopamine (dopamine can’t get reabsorbed by the synaptic cleft)
Chlorpromazine (pg 252)
Antagonist; occupies the dopamine site on the D2 receptor = prevents receptor activation
Major depression
Mood disorder characterized by prolonged feelings of worthlessness and guilt, disruption of eating habits, sleep disturbances, general slowing of behaviour, & frequent thoughts of suicide
3 different drugs with antidepressant effects
-Monoamine oxidase (MAO) inhibitors -tricyclics antidepressant -Second generation antidepressants
Monoamine oxidase (MAO) inhibitor
Blocks the enzyme MAO from degrading neurotransmitters such as dopamine, noradrenalin, and serotonin = inhibits the breakdown of these chemicals
Tricyclics antidepressant
1st generation antidepressants drug. A three ring chemical structure that blocks serotonin reuptake transporter proteins = serotonin stays in the synaptic cleft longer
2nd generation antidepressant
Drug with similar actions as tricyclics but more selective. They Don’t have the 3 ring structure
Selective serotonin reuptake inhibitor (SSRI)
Tricyclic antidepressant drug that blocks the reuptake (absorption) of serotonin into the presynaptic terminal
Side effects of antidepressants
Increased anxiety, sexual dysfunction, sedation, dry mouth, blurred vision, and memory impairment
Obsessive compulsive disorder (OCD)
Repeated involuntary thoughts and actions. Ex. Obsessive thoughts and compulsive behaviours.
Bipolar disorder
Mood disorder characterized by periods of depression alternating with normal periods and periods of intense excitation, or mania
Mood stabilizers
Drugs that treat bipolar disorder. It mutes the intensity of one pole of the disorder, thus making the other pole less likely to recur
Opioid
Any compound that binds to a group of brain receptors that are also sensitive to morphine
Opioid analgesics
Drugs with sleep-inducing (narcotic) and pain-relieving (analgesic) properties; used to be called narcotic analgesic
2 natural sources of opioids
1) opium 2) the brain
Friedrich Serturner
German chemist who synthesized two pure opiates: codeine(cough medicine, pain reliever) & morphine(converted from codeine by the liver)
Endorphin
Peptide hormone that acts as a neurotransmitter and may be associated with feelings of pain or pleasure; mimicked by opioid drugs (have morphogenetic like effects)
The 3 classes of endorphins
-Endomorphines -enkephalins -dynorphins
What are the 3 endorphin receptors
-mu (morphine) -kappa( -delta
Competitive inhibitors
Drug such as nalorphine and naloxone that acts quickly to block the actions of opioids by competing with them for binding sites; used to treat opioid addiction
Withdrawal
Sickness that results when drug use is stopped. Symptoms are physiologically and behaviourally opposite those produced by the drug.
2 groups of psychomotor stimulants
-behavioural stimulants -general stimulants
Behavioural stimulants
Drugs that increase motor behaviour as well as elevate a persons mood and level of alertness. Ex. cocaine & amphetamine
What do local anaesthetics agents (like cocaine) reduce?
A cells permeability to Na+ ions and so reduce nerve conduction
Amphetamine
Synthetic compound discovered in attempts to synthesize the neurotransmitter epinephrine.
Benzedrine
Form of amphetamine used to treat asthma in 1940’s. Improves performance on mental-efficacy tests. Abused by students.
General stimulants
Drugs that cause overall increase in metabolic activity of cells. Ex. Caffeine
Caffeine
Stimulant that inhibits an enzyme that breakdowns the 2nd messenger cyclic adenosine monophosphate (cAMP). In other words it allows the increase production of cAMP
Effect of caffeine
Increase in cAMP = increase in glucose production within cells = more available energy and higher rate of cellular activity
Psychedelic Drugs
Drug that can alter sensation and perception;
4 major groups of psychedelics
1) Acetylcholine psychedelics
2) Norepinephrine psychedelics
3) Serotonin psychedelics
4) Tetrahydrocannabinol (THC)
Acetylcholine psychedelics
Either blocks or facilitates transmission at acetlycholine synapses in the brain
Norepinephrine psychedelics
Mescaline, obtained from the peyote cactus
Serotonin psychedelics
Lysergic acid diethylamide and psilocybin. Affect serotonergic neurons.
Tetrahydrocannabinol (THC)
active ingredient in marijuana obtained from Cannabis sativa plant. Acts on CB1 and CB2 receptors (THC receptors). Receives anandamide neurotransmitters.
Anandamide
Neurotransmitter that acts on CB1 and CB2 (THC) receptors. Inhibits adenyl cyclase.
Role of anandamide on memory
Either has negative effect on memory or positive effect on memory overload (prevents brain from being overwhelmed with infromation
Disinhibition theory
Alcohol has a selective depressant effect on the cortex, region of the brain that controls judgment, while sparing subcortical structures responsible for more-primative instincts, such as desire
MacAndrew and Edgerton time out theory about alcohol
Effects of alcohol represents “time out” from daily life that normal apply such as learned behaviour specific to culture, group, and setting
Alcohol myopia (nearsightedness)
Nearsighted behaviour displayed under the influence of alcohol: local and immediate cues become prominent, and remote cues and consequences are ignored. Explains many lapses in judgement that lead to risky behaviour.
substance abuse
Use of a drug for the psychological and behavioural changes that it produces aside from its therapeutic effects
Addiction
Desire for a drug manifested by frequent use of the drug, leading to the development of physical dependence in addition to abuse. A tolerance is built.
Withdrawal symptoms
Physical and psychological behaviour displayed by an addict when drug use ends.
Psychomotor activation
Increased behavioral and cognitive activity; at certain levels of consumption, the drug user feels energetic and in control. Led to the hypothesis that all abused drugs act on the same target in the brain = mesolimbic dopamine system
What hormone contributes to the sex differences in addiction?
Estrogen
Incentive salience
Quality acquired by drug cues that become highly desired and sought-after incentives in their own right. Ex. Collecting pipes
Terry Robinson and Kent
Berridge (2008) wanting-and-liking theory (incentive-sensitization theory)
When a drug is associated with certain cues, the cues themselves elicit desire for the drug. Ex. Being around friends who smoke. Cravings are unconscious.
Location of wanting and liking in the brain
Liking: may be due to activity of opioid neurons
Wanting: may be due to activiy in the mesolimbic dopamine system
Testosterone
Sex hormone secreted by the testes and responsible for tne distinguishing characterisitcs of the male
Steroid hormone
Fat-soluble chemical messenger synthesized from cholesterol.Testosterone and cortisol are steroids.
Peptide hormones
Chemical messenger synthesized by cellular DNA that acts to affect the target cells physiology.
Three main functional hormone groups
1) Homeostatic hormones
2) Gonadal (sex) hormones
3) Glucocorticoids
Homeostatic hormone
Maintain internal metabolic balance and regulate physiological systems in an organism. Ex regulating blood-sugar levels.
Gonadal (sex) hormone
Control reproductive functions and bestow sexual apperance and identity as male or female
Glucocorticoids
Steroid hormones, such as cortisol secreted in times of stress; important in protein and carbohydrate metabolism
Diabetes mellitus
Failure of the pancreatic cells to secrete enough insulin or non at all
Hyperglycemia
The rise in blood-glucose levels due insulin not instucting cells to take up glucose.
Organizational hypothesis
Proposal that actions of hormones in development alter tissue differentiation. Ex. Testosterone masculinizes the brain
SRY gene or sex-determining region
Gene in the male Y-chromosome that causes the undifferentiated gonads to develop into testes
3 lines of evidence for the sex-related cognitive differences in males and females
1) Males excel in spatial tasks and females excel in verbal tasks
2) When womens estradiol and progesterone (sex hormones) levels are at their lowest they do better on spatial tasks
3)
Anabolic steroids
Class of synthetic hormones related to testosterone that have both muscle-building (anabolic) and masculinizing (androgenic) effects
Health risks of anabolic steroids
Causes the body to reduce the manufacture of testosterone = reduces male fertility and spermatogenesis
Stressor
stimulus that challenges the bodys homeostasis and triggers arousal. Consists of a fast and slow response.
Posttraumatic stress disorder (PTSD)
Syndrome characterized by physiological arousal symptoms related to recurring memories and dreams related to a traumatic event - for months or years after the event. May be caused by damage to the hippocampus.
Fast-acting parthway (sympathetic) fight-or-flight
1) Hypothalamus sends sends neural message to stimulate sympathetic system
2) Sympathetic division stimulates the medulla in the adrenal gland
3) Adrenal gland releases epinephrine into the circulatory system
4) Epinephrine surge activates cell bodys, endocrine glands, and brain to prepare the buddy for sudden burst of activity.
Slow-acting pathway (parasympathetic) repair the body
1) Hypothalamus releases CRH into the pituitary gland
2) Pituitary gland releases ACTH, which acts on the cortex of the adrenal gland
3) Adrenal cortex releases cortisol into the circulatory system
4) Cortisol activates the body’s cells, endocrine glands, and brain
Benzedrine
Form of amphetamine first used to treat asthma. Was later used by students to help them study b/c it improves mental efficiency.
General stimulants
Drugs that cause an overall increase in the metabolic activity of cells. Ex. Caffeine
