Chapter 6 - Drugs & Hormones Flashcards
Psychoactive Drugs
substances that act to to alter mood, thought or behavior
- for recreation (make it abnormal)
- to manage neuropsychological illness (make it normal)
Drug Routes
safest → least safe
high dose → low dose
- stomach
- intestines
- skin
- muscles
- lungs
- injected into:
- blood
- CNS
- receptors
Drug Routes
- characteristics of psychoactive drugs
water-soluble → to pass BBB
diluted in body
weak acids: stomach → bloodstream
weak bases: intestines → bloodstream
Blood-Brain Barrier
- characteristics
- passage of substances
brain capillaries have tight junctions covered by astrocyte feet
small uncharged molecules diffuse across
- CO2 & O2
active transport
- aa’s, glucose, fats
large, charged molecules can’t leave capillary
Blood-Brain Barrier
- (3) areas not protected
1) Pituitary Gland
2) Pineal Gland
3) Area Postrema (induces vomiting)
Drug Effects vs. Actions
EFFECTS → changes in mood/thought/behavior
ACTIONS → changes in neurochemistry
Drug Actions
affect stages of chemical transmission
synthesis, storage, release, activation, inactivation, reuptake/degradation
Agonist vs. Antagonist
Agonist
increases synapse functioning
- ↑ synthesis, storage, release
- aids binding/mimics
- ↓ inactivation/degredation/reuptake
Antagonist
decreases synapse functioning
Classification of Psychoactive Drugs
- (5)
based on drug effects
I. Sedatives & Antianxiety Agents
II. Antipsychotic Agents
III. Antidepressants
IV. Narcotic Analgesics
V. Psychomotor Stimulants
I. Sedatives & Antianxiety Agents
GABA agonists
cross-tolerance
anxiety relief, disinhibition, sedation, sleep, anesthesia, coma
Antianxiety Agents → less drastic effects but short-term use
I. Sedatives & Antianxiety Agents
-
Sedatives (2)
- actions & effects
- dose (2)
(INCREASE TIME PORE IS OPEN)
→ dose-dependant relationship
- anxiety relief, disinhibition, sedate, sleep, anesthesia, coma
tolerance develops with frequent use
a) Alcohol
* ↑ GABA binding
b) Barbiturates
* mimic GABA → binds to receptor → ↑ Cl influx
I. Sedatives & Antianxiety Agents
-
Antianxiety Agents
- actions & effects
a) benzodiazepines (Valium, Xanax)
Action: ↑ GABA binding → ↑ frequency of pore opening
- indirectly ↑ Cl influx
Effects: anxiety relief
Why are Benzodiazepines safer & harder to overdose on than Barbiturates?
Barbiturates → mimic GABA, ↑ Cl influx directly
Benzodiazepines → ↑ GABA binding, ↑ Cl influx indirectly
- limited by amount of GABA
II. Antipsychotic Agents
- Effects (2)
- Action
Antipsychotics (neuroleptics): Haloperidol, Chloropromazine (FGAs)
→ Dopamine (DA) antagonists
SGA’s - also block seratonin receptors
EFFECT → ↓ psychosis symptoms (hallucinations, delusions)
- side-effect: dyskinesia → impaired motor control (like Parkinsons)
ACTIONS: blocks D2 DA receptors
DA Hypothesis of Schizophrenia
- support?
IDEA: excess DA activity causes schizophrenia symptoms
supported by similar symptoms in chronic amphetamine (DA agonist) users
III. Antidepressants (3)
- Effects
seratonin agonists
a) monoamine oxidase (MAO) inhibitors
b) Tricyclic Antidepressants
c) Selective Serotonin Reuptake Inhibitors (SSRIs)
↓ Depression symptoms
- guilt, worthlessness, disruption of eating/sleep, slowing of behavior, suicidal thoughts
III. Antidepressants
-
Drug Actions
- MAOIs
- Tricyclic Antidepressants
- SSRIs
1) ↑ NE & seratonin (& DA)
* block deactivating enzyme in axon terminals
2) ↑ NE & seratonin
* block reuptake
3) ↑ seratonin
* ↑ hippocampal neurogenesis
III. ANTIDEPRESSANTS → MAOIs
- food-drug interactions
↑ availability of monamines
- precursors in diet
- tyramine → ↑ BP
III. Antidepressants
- Why do effects take weeks to work?
metabotropic receptors → ↑ transcription of BDNF
→ facilitates rebuilding of brain & neuron health
- ↓ cell death
- ↑ neurogenesis in certain areas
-
hippocampus →turns off stress response
- relief from depression symptoms
-
hippocampus →turns off stress response
IV. Narcotic Analgesics
- effects (2)
natural or synthetic drugs derived from opium poppy
→ opium, codeine, morphine, heroin
↓ GABA release → ↑ DA (addictive)
narcotic → sleep-inducing
analgesic → pain-relieving
IV. Narcotic Analgesics
- drug actions
act on endorphin (endogenous morphine-like receptors) receptors in brain
V. Psychomotor Stimulants
- (3)
a) Behavioral Stimulants
b) General Stimulant
c) Psychedelic Drugs
V. Psychomotor Stimulants (Psychotropics)
a) Behavioral Stimulants
- effects
- actions
→ agonists
cocaine - ↑ DA, NE, seratonin
amphetamine - ↑ DA, NE
effects: ↑ motor behavior, mood & alertness
actions:
- block DA reuptake
- ↑ DA release (amphetamine)
V. Psychomotor Stimulants (Psychotropics)
b) General Stimulants
- effects
- action
caffeine → ↑ glucose (metabotropic receptors)
effects: ↑ alertness & motor behavior
actions: blocks adenosine receptors (inhibitory NT)
V. Psychomotor Stimulants (Psychotropics)
c) Psychedelic & Hallucinogenic Stimulants
→ Psychedelic Drugs
- effects
- actions
↑ seratonin & NE
LSD → acid
psilocybin → mushrooms
mescaline → peyote
effects: alter sensory reception & thoughts
actions: alters various NS system functioning
Hormonal Communication
- form of?
form of chemical communication
Hormones
- production
chemical messengers secreted directly into blood
produced & secreted by endocrine cells & carried via blood to target cell
Endocrine System
system of glands that release hormones into bloodstream
controlled by hypothalamus via pituitary gland
Major Endocrine Glands
pituitary gland
pineal gland → melatonin
thyroid gland → homeostasis
thymus → immune system
adrenal gland → stress response (fast & slow)
pancreas
ovary/testis
Hierarchical Control of Hormones
- (4) levels
I. Hypothalamus
II. Pituitary Gland
III. Target Endocrine Glands
IV. Target Organs & Tissues
Hierarchical Control of Hormones
(4) levels
I. Hypothalamus
sensory stimuli & cognitive activity
→ produces neurohormones (releasing hormones)
Hierarchical Control of Hormones
II. Pituitary Gland
neurohormones enter:
-
anterior pituitary through veins
- produces its own hormones
- posterior pituitary through axons
→ enter bloodstream to target endocrine glands
Hierarchical Control of Hormones
III. Target Endocrine Glands
IV. Target Organs & Tissues
in response to pituitary hormones
→ release own hormones → stimulate target organs/tissues
in response, hypothalamus & pituitary ↓ hormone production
Hormone Classification by Function
(3)
a) Homeostatic Hormones
b) Stress Hormones (Glucocorticoids)
c) Gonadal (Sex) Hormones
a) Homeostatic Hormones
Maintain internal metabolic balance & system regulation
→ sugars, proteins, carbs, salts, water in blood, brain, cells etc.
- aldosterone, vasopressin
b) Stress Hormones (Glucocorticoids)
secreted in times of mental/physical stress
works in opposition to homeostatic hormones
c) Gonadal (Sex) Hormones
sexual appearance & gender identity
control reproductive functions
role in some cognitive & motor functions
Vasopression
ADH
↑ water reabsorption (retention)
Stressor
stimulus that challenges homeostasis & triggers arousal
Stress Response
physiological & behavioral arousal & attempt to ↓ stress
Stress Response
- (2) types
a) Fast-Acting Pathway
b) Slow-Acting Pathway
Stress Response
a) Fast-Acting Pathway
(5)
hypothalamus sends neural msg through spinal cord
→ activates sympathetic ANS → fight or flight
→ stimulates medulla of adrenal gland
→ releases epinephrine
→ activates cells/endocrine glands/brain
Stress Response
b) Slow-Acting Pathway
hypothalamus → releases CRH into pituitary gland
→ releases ACTH into adrenal cortex
→ releases cortisol into blood
→ activates cells, endocrine gland, brain
Function of:
a) Fast-acting Pathway
b) Slow-acting Pathway
a) stimulates cell metabolism
b) turn off systems not immediately required to deal with stressor
- insulin
- reproductive functions
- growth hormone production
Stress Response
- brief vs. prolonged
stress responses → generally brief
- turned on/off by hippocampus
prolonged stress can lead to hippocampal damage
Gonadal Hormones
- (2) effect types
a) Organizational
b) Activational
Gonadal Hormone Effects
a) Organizational
during development
alter tissue differentiation causing enduring body/brain changes
SRY gene on Y xsome → causes male gonads to develop
- testes secrete androgens → Anti-mullerian hormone inhibits female sex organs
testosterone masculinizes brain → cognitive differences
Sex-Related Cognitive Differences → Evidence (3)
a) males → better @ spatial tasks
females → better @ verbal tasks
b) fluctuations in spatial/verbal tests scores across menstrual cycle
c) pre & post menopausal women, stages of pregnancy, M/F with various levels of circulating hormones → affects cognitive functions
XY but androgen-insensitive
appear female
→ attracted to men
Gonadal Hormone Effects → b) Activational
circulating sex hormones across lifespan
- transient effects on body/brain/behavior
(puberty onward)
Activating Hormones Effects in Women
→ act on hypothalamic nuclei
low estradiol phase
✓ spatial tasks
x verbal tasks
high estradiol phase
x spatial tasks
✓ verbal tasks
Role of Amygdala & Hypothalamus in Sexual Behavior
Amygdala
- M/F → influences sexual motivation
Hypothalamus
- M/F → controls copulatory behavior
Sexual Orientation
person’s sexual attraction to:
- opposite sex
- same sex
- both sexes
Gender Identity
person’s feelings of being male/female
