Biological Psychology EXAM 3 (Ch 10-15)

Psychoactive drug

A substance that alters mood, perception, mental functioning, or behavior

Addiction

A pattern of drug use that impairs ability to fulfill responsibilities. leads to risky behavior, dangerous situations, and causes legal or social problems

Addiction (Koob & Volkow definition)

A chronic, relapsing disorder involving compulsive drug seeking, loss of control in limiting intake, and withdrawal symptoms when access is prevented

escalation in frequency and intensity of use over time

Core features of addiction are-

Binge/intoxication stage

Drug use driven by pleasure (hedonic effects) and social influences (pressure/norms)

Withdrawal/negative affect stage

Characterized by physical & motivational ________, dysphoria, irritability, and emotional distress

Preoccupation/anticipation stage

Compulsive drug seeking and craving at the expense of other rewards

positive reinforcement (pleasure) to negative reinforcement (relief of withdrawal)

Transition to addiction is the shift from- ( ___ to ___ )

Positive reinforcement

Drug use increases because it produces rewarding effects

Negative reinforcement

Drug use increases because it removes unpleasant withdrawal symptoms

Human drug research methods

Double-blind studies, Drug vs Placebo, self-reports, physiological measures (BP), neuroimaging

Animal drug research

Self-administration and behavioral models

Operant self-administration

Behavior (e.g., lever pressing) leads to drug delivery

- Presumptive rewarding effects of drug increase occurrence of this behavior in the future

Conditioned place preference (CPP)

Preference for environment associated with drug reward

Two-bottle preference test

Measures voluntary drug consumption

Elevated plus maze

Assesses anxiety during withdrawal

Forced swim test

Measures depressive-like behavior

Startle response

Measures withdrawal-related sensitivity

Acquisition (self-administration)

Learning drug-taking behavior/ operant-reinforce contingency (model of vulnerability)

Maintenance

Stable drug use with ongoing reinforcement

- Well-trained animals presented with pharmacological or

behavioral challenges

Reinstatement

Return of drug-seeking after extinction, or removal of operant-reinforcer contingency

- Behavior can be reinstated by drug, cues, stress

- model of relapse 😢

Extinction

Removal of drug reinforcement reduces behavior

Acquisition, Maintenance, Reinstatement, (extinction)

phases of Self-administration are-

Relapse triggers

Drug exposure, cues, stress are-

Classical conditioning in addiction

Environmental cues become associated with drug effects

in a different setting

When a drug is taken ____, it is more likely to result in an overdose

Learned tolerance

linked to environment; overdose risk increases in new settings

Sensitization

Increased response to drug after repeated exposure

- in humans is reflected in craving or wanting drug

Conditioned physiological responses

Body prepares for drug effects in familiar contexts

Craving

Conditioned response to drug-related cues

Negative Reinforcement

Drug use removes unpleasant effects of withdrawal

- Increases the proclivity to use drugs again

Mesolimbocortical dopamine system

Primary reward pathway in the brain

Nucleus accumbens (NAc), medial forebrain bundle, ventral tegmental area (VTA)

Key structures in reward system (mesolimbocortical DA)

Role of dopamine (DA)

Signals reward and prediction errors

- implicated in the rewarding effects of drugs, food, sex, and electrical stimulation.

ventral tegmental area (VTA) and Nucleus accumbens (NAc)

Most drugs increase dopamine in the-

ventral tegmental area (VTA)

midbrain structure where dopamine is produced: associated with mood, reward, and addiction

Nucleus Accumbens (NAc)

structure receives dopamine from ventral tegmental area and is thought to be involved in reinforcement and attention

Cocaine and amphetamines

drugs that increase dopamine by blocking reuptake or stimulating release

Opioids

Increase dopamine indirectly by reducing GABA inhibition from VTA

- Activate _______ receptors in VTA, NAc

PCP

drug that blocks glutamate receptors (excitatory neurotransmitter)

Alcohol

drug that enhances GABA, increases dopamine, releases opioid peptides

Nicotine

drug that activates acetylcholine receptors directly or indirectly through interneurons

Role of nucleus accumbens

Integrates emotional and motivational input into action

(-receives input from amygdala, frontal cortex, and hippocampus)

Prefrontal cortex

Involved in compulsive drug use and decision-making

- Compulsive use may be due to glutamatergic projections from ______ to NAc

Intracranial self-stimulation

Animals learn to press a lever to stimulate reward brain areas (over food and safety!! 😱)

- Most sensitive areas contain DA neurons, such as medial forebrain bundle

Prediction error (dopamine theory)

Dopamine signals respond to unexpected or missing expected rewards

dendritic complexity

Neuroplasticity in addiction Increases ________ in nucleus accumbens

emotion and learning areas

Craving brain activity include hyperactivity in-

frontal lobe dysfunction

Pathologically, addiction brain changes include malformed dendrites and-

Eliminate negative reinforcement

Withdrawal treatment goal is to-

Cue avoidance

Avoid triggers associated with drug use

Extinction therapy

Reduce conditioned responses to drugs

Spontaneous recovery

Extinguishing drug responses can have risk of relapse in drug-seeking behavior

Agonist treatment

Mimics drug effects (e.g., methadone for opiate addiction, nicotine patch)

Antagonist treatment

Blocks drug effects (e.g., naltrexone for opiate and alcohol)

- don't replace the drug, so compliance depends on the addict's motivation to quit

Aversive treatment

Produces unpleasant reaction to drug (e.g., Antabuse for alcohol addiction)

- Treatment compliance depends on the addict's

motivation to quit.

Anti-drug vaccines

stimulate the immune system to make antibodies that decrease the rate of into the brain

Cognitive Behavioral Therapy (CBT) and contingency management

Psychological treatments for addiction include

Cognitive Behavioral Therapy (CBT)

a popular integrative therapy that combines changing self-defeating thinking with changing behavior)

contingency management

undesirable behavior is not reinforced, while desirable behavior is reinforced

Pharmacological treatment

is controversial due to belief that recovery should involve the exercise of will and that it is wrong to give an addict another drug, such as methadone.

combining behavioral and pharmacological approaches

Addiction treatment had higher success when-

Heritability of addiction

Genetic contribution varies by drug (e.g., alcohol 50-60%, cocaine ~72%)

Type 1 alcoholism

Late-onset, influenced by environment

Type 2 alcoholism

Early-onset, largely genetic

Genes

Often affect neurotransmitter systems or drug sensitivity

Homer gene (glutamate regulation)

Knockout mice lacking either of two ________, which regulate glutamate activity, are more susceptible to cocaine

- Absence increases cocaine vulnerability

Clock gene

Mice lacking ________ release more dopamine in reward areas of the brain and are more vulnerable to cocaine's effects.

- Increases dopamine release and addiction risk

Opioid receptor gene (G allele)

Individuals report greater intoxication and are 3x more likely to have a history of alcoholism.

Low sensitivity to alcohol

People who do not respond to the negative effects of alcohol, such as motor impairment, are 4x more likely to become alcoholic later

ALDH deficiency

causes a defect in metabolizing alcohol and decreases risk of alcoholism

Nicotine metabolism deficiency

causes a defect in metabolizing nicotine a protects some people from nicotine addiction

Personality traits linked to addiction

Impulsivity, risk-taking, novelty-seeking, stress sensitivity

high frequency

Increased ________ EEG occurs in alcoholics and their offspring.

P300 wave abnormality

Alcoholics and their offspring also show a reduction in the

normal "dip" in the _______

- Reduced response to stimuli in high-risk individuals

genetics and environment

addiction behavior results from interaction between-

willpower

Addiction cannot be explained by ________ alone

Circadian rhythm

A biological rhythm that lasts about 24 hours

Suprachiasmatic nucleus (SCN)

The main biological clock in mammals located in the hypothalamus

- regulates the pineal gland's melatonin secretion

Regulates sleep-wake cycles, hormone release, body temperature, and other circadian rhythms

What are the function of the suprachiasmatic nucleus?

Eliminates normal 24-hour rhythms (sleep, activity, temperature, etc.)

What is the effect of SCN lesion on rats?

Zeitgebers

External cues that synchronize circadian rhythms (e.g., light)

Light

Most important zeitgeber that supresses melatonin secretion

Pineal gland

Brain structure that releases melatonin

Melatonin

Hormone that promotes sleep and regulates circadian rhythms

Effect of light on melatonin

Suppresses melatonin secretion

Body temperature, metabolism, blood pressure, hormone levels, and hunger

Examples of bodily function circadian rhythms are....

High, low

Cortisol and Epinephrine circadian patterns are ______ after waking, _____ before sleep

Ultradian rhythms

Biological rhythms shorter than 24 hours

Basic rest-activity cycle (BRAC)

90-100 minute cycle of alertness and fatigue

- This cycle also extends into sleep, with 90-minute

variations in arousal

Jet lag

Disruption and desynchronization of circadian rhythms due to time zone changes

- melatonin can "reset" the biological clock to aide with this

jet lag, insomnia, night shift work, blindness

Melatonin helps reset biological clock for those with.....

Retinohypothalamic pathway

Pathway through which light information travels from retina to SCN

Melanopsin

Light-sensitive photopigment in retinal ganglion cells

- explains why some blind individuals entrain to light

light cues

Circadian cycles are self-sustaining and can function in the absence of _________.

Clock genes

Genes that regulate circadian rhythms within the SCN

slightly longer than 24-hour cycles (~24.18 hours)

Isolation study found that Humans naturally follow-

- ex: michel siffre cave experiment

Restorative hypothesis of sleep

Sleep replaces energy and repairs the body

sleep more

Evidence for restorative hypothesis is that animals with higher metabolism-

Adaptive hypothesis of sleep

animal sleep patterns evolved for survival (safety + food access)