Tuesday, February 5
Drugs and Behavior - Chapter 3 (Section 3)
1. Psychoactive Drug: Any substance that affects experience, mood, emotion, activity, or health.
a. Most psychoactive compounds come from evolutionary ancient plants b. Drug will replace and resemble natural neurotransmitters
i. Agonists: Increases production of neurotransmitters.
1. Increases release of neurotransmitters
a. Drug: Amphetamine
2. Bind to autoreceptors and block their inhibitory effect
a. Drug: Clonidine (for high blood pressure)
3. Block the deactivation or reuptake of neurotransmitters
a. Drug: Prozac & Cocaine
4. Bind to postsynaptic receptors and activate them or increase
a. No action potential needed
b. Drug: Nicotine
ii. Antagonist: Decreases production of neurotransmitters.
1. Block production of neurotransmitters
a. Drug: AMPT
2. Decrease neurotransmitters in vesicles Don't forget about the age old question of What is an omnipotent being?
a. Drug: Reserpine (antihypertensive)
3. Block release of neurotransmitters
a. Drug: Botulinum Toxin
4. Activate autoreceptors so that they stop release of
a. Drug: Caffeine
5. Bind to postsynaptic receptors and block neurotransmitters from
a. Drug: Propranolol (beta-blocker) & Haldol (antipsychotic
Don't forget about the age old question of What is the greenhouse effect and what causes it?
2. Addiction/Substance Use Disorder: Compulsive drug craving and use, despite adverse consequences
a. Tolerance: The more you use, the less you feel the drug
i. Rely on bigger doses to get the initial effect
b. Dependence: Compulsive physiological craving or a psychological need to obtain and use the drug
i. Physiological Dependence: Body needs drug for body to function normally.
ii. Psychological Dependence: Rely on drug to complete specific activities. 1. Ex. Get nervous at party - rely on drug to be social
c. Withdrawal: Absence of drug causes physical pain
i. Ex. Drug can cause euphoria, while absence of drug can cause dysphoria. ii. Post Withdrawal Syndrome: Refers to the symptoms that occur when a substance-dependent person stops using. If you want to learn more check out What is the theory of forms by plato?
d. Drug Dependent Newborn
i. Goes through withdrawal symptoms
ii. Increases risk of later addiction, either based on:
1. Parents genetics
2. Physiological craving without consumption of drug
3. Alcohol Use Disorder: A problematic pattern of alcohol use leading to clinically significant impairment/distress, as manifested by at least two of the following: a. Consumed in large amounts or over long periods of time
b. Persistent desire or can’t control consumption
c. Significant amount of time spent consuming
d. Recurrent use inhibits ability to complete obligations If you want to learn more check out What is the value of temperature and pressure at stp?
e. Recurrent use where it is physically hazardous
f. Continue to use regardless of consequences
4. Drug Dependency and Abuse
a. Drug floods “reward pathway” with Dopamine and ramps up Agonist of Dopamine
i. Three different reward pathway hubs:
1. Ventral Tegmental Area (VTA)
a. Origin of reward pathway
b. Release to NAc
2. Nucleus Accumbens (NAc)
a. Motivated and goal-directed behavior
b. Released to Pc
3. Prefrontal Cortex
5. Addiction and Reward Pathways: Continued drug use sharply reduces the number of dopamine receptors in the brain’s reward system
a. Dopamine receptors fade away with drug use
b. Less receptors to bind to dopamine
c. Down regulation of dopamine receptors
d. This is why tolerance increases to get same effect
e. This is why people get hyper-focused on a specific high because other things give them less pleasure because they have less dopamine neurotransmitters
f. Abstinence can be a biological cure to get Dopamine balance back to normal. 6. Drug Class: Depressants: Reduce neural activity and slow body functions a. All depressants are GABA agonists
i. Increase inhibitory postsynaptic potentials and reduce neural activity at site of action. We also discuss several other topics like What dictates the temperature and rainfall in a particular part of the world?
i. Slows down neural processing (ex. judgement)
ii. Acts as GABA agonist
1. GABA inhibits neurotransmitters but alcohol works as an agonist
and speeds things up
iii. Glutamate antagonist
1. Glutamate excites neurotransmitters but alcohol works as an
antagonist and slows things down
iv. Indirectly acts as dopamine agonist
c. Anxiolytics/Sedatives - reduce anxiety
1. Valium, Xanax, Ativan, Klonopin Don't forget about the age old question of What are anorexia nervosa and bulimia nervosa?
d. Hypnotics - induce sleep
i. Ambien, Lunesta, Quaaludes
e. Opiates: Depress neural activity, relieve pain (analgesic), produce feelings of euphoria.
i. Agonists of endorphins and dopamine
1. Decreases pain by being an agonist of endorphins and increases the reward pathway by being an agonist for dopamine
ii. When brain floods with artificial opiates, brain slows production of natural painkilling neurotransmitters (endorphins), leading to higher dependence and opiate use.
iii. With abstinence, endorphins and dopamine will rebound and go back to normal amounts.
1. Morphine, Heroin, Methadone, Prescription Painkillers (codeine,
hydrocodone, oxycodone, dilaudid, fentanyl).
7. Drug Class: Stimulants: Excite neural activity and speed body functions. a. Amphetamines/Methamphetamines
i. High Effect
1. Causes heightened energy and mood
2. Increased concentration
3. Motor agitation and decreased sleep
ii. Effect on Neurotransmitters
1. Triggers release of dopamine (DA agonist)
2. Blocks norepinephrine reuptake (NE agonist)
iii. ‘Post-acute withdrawal’ symptoms:
i. High Effect
2. Elevated mood/euphoria
3. Loss of appetite
ii. Effect on Neurotransmitters
1. Blacks reuptake of dopamine, norepinephrine, and serotonin
iii. ‘Crash’ of Symptoms
1. Occurs 15-60 minutes after intake
a. Irritability, anxiety, tremors, low mood
iv. Super active cocaine Molecule: Cocaine and alcohol in liver 8. Risk of Overdose
a. Approximately 70,000 drug overdoses occur annually in the United States. i. 90% unintentional
ii. 10% suicide
iii. Opioids are most common - fentanyl
b. Most common drugs:
1. Fentanyl, heroin, hydrocodone, oxycodone
9. Psychedelics: Distort perceptions, alter mood and thinking
a. Act on serotonin receptors as an agonist (increase production) b. One class of drug that doesn’t target reward pathway
c. Not physiologically addictive but can have psychological dependence. d. Doesn’t need to take more to feel the same high.
10. Ecstasy/Molly/MDMA (Methylenedioxymethamphetamine)
a. Synthetic stimulant that increases dopamine and serotonin levels
b. High Effect
i. Heightens physiological arousal
iv. Artificial feeling of social connectedness and intimacy
v. Can last up to hours
1. Releases oxytocin
a. Leaves and flowers of cannabis/hemp plant
i. Anandamide & 2-AG: Brains natural cannabinoid.
1. Increases appetite
2. Decreases pain sensitivity / increases pleasure
3. Impair memory
ii. THC (cannabinoid): Psychoactive chemical that produces high in cannabis 1. Acts on cannabinoid receptors in the brain.
2. Inhibits release of glutamate and GABA.
3. Inhibiting GABA release in the VTA leads to increased dopamine
Friday, February 8
Brain and Behavior - Chapter 2
1. Nervous System
a. Central Nervous System
1. Cerebellum: Coordination + muscle memory
a. Cerebral Cortex: Controls perception, emotion, movement,
and thought. Contains 20% of brains neurons.
i. Cerebral Lobes:
1. Occipital: Visual info
2. Temporal: Hearing (Auditory Cortex) and
Language (Wernicke’s Area).
3. Parietal: Touch (Somatosensory Cortex)
4. Frontal: Speech and movement (motor
ii. Spinal Cord: Signals to and from brain.
b. Peripheral Nervous System
i. Somatic Nervous System (voluntary): Relays info to and from skin and skeletal muscles.
ii. Autonomic Nervous System (involuntary): Relays info to internal organs 1. Sympathetic: Arousal and stress
2. Parasympathetic: Calming
2. Brain Development
a. Prenatal Brain Development
i. By 3 weeks, a neural tube of stem cells form
ii. Neural stem cells divide and multiply
1. Produce neurons and glial cells
iii. Eventually thicken and develop the brain’s main regions
b. The Formative Years
i. Birth-3 years: Branching ‘neural networks,’ allowing walking, talking, and remembering.
ii. 3-6 years: Frontal lobe develops allowing rational planning.
iii. 6-13 years: Association areas strengthens, improving thinking, memory, language, and reading.
3. The Brainstem: Supports life-sustaining bodily functions.
a. Medulla: Controls heart rate, blood pressure, and reflexes such as vomiting, sneezing, and coughing.
b. Pons: Regulates breathing, salivating, swallowing, basic motor control and balance, receives auditory and pain signals (sensory input).
4. Huntington Disease affects what parts of the brain?
a. Basal Ganglia
b. Thalamus: Dampens other material and spotlights certain information (someone says name at party)
c. Cerebellum: Muscle memory (helps remember new skill - procedural memories) + enables “auto-pilot” response.
5. The Limbic System: Allows us to process large amounts of emotion and memory on daily basis.
b. Hypothalamus: Regulates the endocrine system (through pituitary glands), hormones; controls stress response, and sleep-wake cycles.
i. Encodes long-term memories and organizes them in brain. ii. Helps us remember how to get from point A to point B. iii. Neurogenesis: The process of forming new neurons within the brain d. Amygdala:
i. Controls emotional/motivational states
ii. Notices unknown stimuli
iii. Fear processing
1. “Threat Management System”
e. Anterior Cingulate Cortex (ACC):
i. Connects Limbic System to Prefrontal Lobe
ii. Active when consciously dealing with emotions (top down) iii. Responds to other people’s pain (someone else is crying) 1. Connectivity