Physiological Psychology Lecture #4 Flashcards
Positive Reinforcement
Add something to the environment.
Negative Reinforcement
Remove something form the environment.
The regions that substances effect
- Basal Ganglia
- Amygdala
- PFC
Basal Ganglia and Substance Exposure
Repeated exposure = decrease sensitivity = tolerance.
Amygdala and Substance Exposure
Withdrawal feelings = motivation to seek out substances.
PFC
Reduced impulse control.
Adolescence = 50% of substance abuse, increase severity and polysubstance use disorder.
What structures are involved in the reward system?
- Ventral Tegmental Area (VTA)
- Nucleus Accumbens
- Amygdala
- Hippocampus
- Prefrontal cortex
Ventral Tegmental Area (VTA)
Dopamine rich nucleus that mediates reward system.
- Located in midbrain.
- Sends dopamine to the nucleus accumbens, hippocampus and prefrontal cortex.
Increases VTA pathways–implicated in OCD.
Nucleus Accumbens
Involved in all motivational-relevant stimuli = rewarding or aversive.
Amygdala
Happiness and enjoyment.
Anxiety, irritability, and unease-withdrawal feelings = motivation to seek out substances.
Hippocampus
Memory and learning.
Prefrontal Cortex
Reasoning, problem-solving, impulse control, creativity, perseverance.
Mesolimbic Dopamine Pathway
Route between VTA, nucleus accumbens, and limbic system.
- Key pathway in pleasure and reward.
- Substance use.
Mesocortical Dopamine Pathway
Route between VTAA/nucleus accumbens, and PFC
Stress
Increase in corticotropin-releasing hormone (CRH)
- Strengthens the amygdala
- Weakens he hippocampus and prefrontal cortex.
Results in:
- Negative emotional state
- Lack of executive control = increase in risk of relapse.
- Memory of relief/cravings.
Is stress a universal construct?
- East Asians: increase in interdependence which results in increase in psychosocial distress.
- Expressions of Stress:
Chinese, Japanese, Korean = emphasis in physical symptoms.
North Americans = emphasize psychological symptoms of stress.
Neural Effects
Cocaine, pathological gambling, nicotine = decrease in gray matter in PFC.
Hypofrontality
Decrease in PFC activity.
- Seen commonly in schizophrenia.
- High comorbidity with SUDs
Peptides
Two or more amino acids linked by peptide bonds.
Endogenous Opioids Receptors
Widely distributed through the CNS and PNS–produced by the body itself.
Functions Include:
- modulation of pain response
- reward and reinfrocement
- inhibit flee response
Most Common:
- Enkenphalins
- Endorphins
- Dynorphins
Endogenous Peptides and Substance Abuse
- Mediate the reward and reinforcement properties.
- Drugs of abuse/exogenous peptides = increase endorphins and enkephalins which leads to a giant dopamine surge.
Moderate Drinking Impact
Small amounts still increase risk of CVD-related illnesses. Risk attenuated by healthy lifestyle.
Moderate Drinking Guidelines
Females = up to 1 drink per day
Males = up to 2 drinks per day
Heavy Drinking Guidelines
Females = 8 or more per week
Males = 15 or more per week
Binge Drinking (in 2-3 hours)
Females = 4 or more
Males = 5 or more
ETOH Cultural Factors
- 5-23% of population are hangover “resistant”.
- Approx. 36% of East Asians experience Asian flush.
Absorption of Alcohol
GI Tact, 20% stomach, 80% small intestine.
- Food inhibits absorption by causing oxidation of alcohol.
- Impacts vitamin absorption.
Metabolism of Alcohol
Primary hepatic (90%)
- Metabolized by alcohol dehydrogenase requires B vitamins.
Excretion of Alcohol
Urine
- Diuretic properties leads to decreased nutrients and dehydration.
Neural Effects of Alchol
ETOH = Overall CNS Depressant
Wernicke-Korsakoff Syndrome
Thiamine Deficiency
- Thiamine plays roles in brain cell energy production and maintenance and synthesis of myelin.
Alcohol Neuropathy
Peripheral Nerve Damage
Alcoholic Cerebellar Damage
Deterioration of cerebellar neurons.
- Chronic incoordination, slurred speech, jerky movements, tremor, nystagmus.
Alcoholic Myopathy
Progressive muscle damage.
- Symptoms include:
Muscle atrophy, stiffness, spasm, and spasms and cramps
Fetal Alcohol Syndrome
- Umbrella term for a range of physical, cognitive and behavioral disorders cause by prenatal alcohol exposure.
- 1-5% of first grade children has FASD.
- Small head, flat mid-face, thin upper lip, short nose, small eye openings, low nasal bridge.
Stimulant Pharmacokinetics
Impact the brain’s level of epinephrine/norepinephrine, dopamine and serotonin.
Primary Risk Factors of Stimulants
- Reduced seizure threshold.
- Increase blood pressure, heart rate, hypertension which can lead to increased risk of store, MI.
- Poor appetite, mood swings, anxiety, insomnia.
Toxic Levels = paranoia, psychosis.
Nicotine Absorption
Enters blood stream via lungs.
Reaches the brain in 7 seconds.
Mimics Ach = arousal, learning, memory and emotion.
Nicotine Effects
Binds to nicotinic receptors which leads to changes in cerebral metabolism.
Stimulates adrenal glands which leads to increase BP, HR, respiration, alertness, and epinephrine.
Nicotine Metabolism and Excretion
- Increased metabolism.
- Metabolized by liver, lungs, kidneys = cotinine.
- Excreted via Urine.
Cannabis
- THC mimics anandamide which effects the endocannabinoid system.
- THC is much more potent than anandamide.
- Effects energy, mood, appetite, and perception of time.
Absorption of Cannabis
- Inhalation–peak plasma concentration 3-10 minutes.
- Oral–peak plasma concentration roughly 120 minutes.
Distribution of Cannabis
Rapidly to well vascularized organs.
Accumulates in adipose tissue.
Metabolism of Cannabis
Predominantly hepatic.
- Able to cross the placenta; released in breast milk.
- Excreted through urine, feces, and sweat.
2 Categories of Hallucinogens
- Classic (impact serotonin): LSD, psillocybin, peyote)
- Dissociative (contribute to reduced control and disconnection): PCP, ketamine.
Sugar
- High sugar diets lead to decrease in brain-derived neurotrophic factors.
- BDNF modulates growth, development and communication between synapses.
Technology Addiction
- Increased used = increase SUD, ADHD, Depression, Anxiety, poor coping.
