PSY 241 Lecture 20

  1. Opiates
    • Opium poppy plants contain morphine, an effective analgesic, or painkiller
    • Morphine and heroin related and highly addictive
    • Opiates bind to opiod receptors in brain, especially in the periaqueductal gray to reduce pain
    • Also found in the hypothalamic, and limbic regions of the brain
  2. Endogenous opioids
    • Enkephalines (in head)
    • Endorphins (engodenous morphine)
    • Dynorphins (dynamic morphine)
  3. Opioid Receptors
    • Delta
    • Kappa
    • Mu

    • Metabotropic receptors
    • If blocked, effects of opiates can be reversed
    • Rewarding effects are thought to be mediated by mu receptors in the Ventral Tegmental Area which when activated cause an increase in dopamine
    • Effect is caused by inhibition of GABA in the VTA
  4. Naloxone
    • Antagonist that can be used to reverse heroin overdose
    • Effective in relieving craving in alcoholics
  5. Marijuana
    • Main ingredient: delta-9-tetrahydrocannabinol (THC) - found in Cannabis Sativa
    • Depressant - stimulation, mild hallucination, parnoia
    • Receptros found in substantia nigria, hippocampus, and cortex
  6. Cannabinoid receptors (CB1)
    • Mediate effects of THC 
    • Are metabotropic receptors
    • Antagonist at CB1 receptors may be useful for weight loss
  7. Endocannabinoids
    Analogs of marijuana produced in the brain, such as anandamide
  8. Stimulants
    • Increase activity of nervous system
    • Alerting and activating effect

    • Nicotine - tobacco plant
    • Cocaine - Coca shrub
    • Amphetamine - Africa shrub - khat
  9. Nicotine
    Increases heart rate, blood pressure, digestive action, and alertness

    • Acts an agonist on nicotinic ACh receptors
    • in the cortex it enhances cognitive function
    • in the ventral tegmental area it stimulates rewarding/addicting effects
  10. _______________________ normally reduce transmitter release but are blocked by _________, resulting in increased transmitter release
    Presynaptic adenosince receptors normally reduce transmitter release but are blocked by caffeine, resulting in increased transmitter release
  11. Cocaine
    • Used as an anesthetic in soda (Coca-Cola) but is  highly addictive because when smoked (crack) or snorted it produces strong pleasurable effects
    • Acts by blocking reuptake of monoamine transmitters so that they accumulate in synapses throughout the brain, boosting their effects
    • Heavy cocaine use raises risk of serious side effects like stroke, psychosis, loss of gray matter, and severe mood disturbances
  12. Amphetamines
    • Work first in axon terminals, causing larger-than-normal release of transmitter by reversing the transporter and causing release
    • Amphetamine then interferes with the breakdown of the transmitter and the synapses become quite potent in their effects on behavior
    • Addiction and tolerance develop rapidly
    • Prolonged use leads to symptoms that resemble those of schizophrenia or brain damage
  13. Dissociative drugs
    • Produce feelings of depersonalization and detachment from reality
    • Phencyclidine (PCP, or angel dust) and ketamine (Special K) are both NMDA-type glutamate receptor antagonists
    • Regular use produces symptoms of psychosis and degenerative brain changes
  14. Emotion
    • Change in physiological arousal, ranging from slight to intense
    • An affective response, feelings that are pleasant or unpleasant
    • Capacity to motivate specific behavior
  15. James-Lange Theory
    • View that physiological changes that occur in response to an event determine the experience of an emotion
    • Ex: "Fear" because of rapid heartbeat
    • Sensory stimuli are received by cortex which triggers activity of the autonomic nervous system which is interpreted as emotion
  16. Superficial facial muscles
    Attach to facial skin
  17. Deep facial muscles
    Attach to skeletal structures in the head
  18. Facial muscles are innervated by two cranial nerves
    • Facial nerve (VII)
    • Trigeminal nerve (V)
  19. Facial feedback hypothesis
    Sensory feedback from our facial expressions can affect our mood
  20. Cannon/Bard Theory of Emotion
    • Emotional stimuli produce excitatory effects on both the autonomic nervous system and the brain (simultaneously)
    • Emotions result from sensory input. All sensory input must go through the Thalamus.
    • Emotions are the result of central processing from the Thalamus to cortex and autonomic nervous system
  21. Schachter's Cognitive Model of Emotion
    • We become aware of physiological reactions, we seek to identify the cause, and we attribute the reactions to our environmental conditions
    • All emotions are essentially the story that the brain makes up to explain the bod reactions
  22. Shacter-Singer Experiment
    • Participants were given an injection of epinephrine, which increases autonomic arousal, or placebo and they were told what to expect (informed), were told a list of side effects not produced by eepinephrine (misinformed) or were not told anything (uninformed)
    • Informed were less affected by confederate because they attributed their physiological reactions to injection
    • Cognitive processes play a role in the interpretation of emotion
  23. The Limbic System
    Emotional expression and experience are mediated by a system of interconnected forebrain structures known as the Papez circuit (later expanded and called the limbic system by MacLean)
  24. Decorticate rage
    Sudden intense rage in dogs with their cortex removes-suggests that the cortex inhibits rage
  25. Phineas Gage
    • Tamping iron through face, skull, and brain and out the other side
    • Damage to medial prefrontal lobes
  26. Amygdala
    Involved in mediating fear and in memories associated with emotionally arousing situations (stressful condition)
  27. Auditory Fear Conditioning
    • Blocked with medial geniculate nucleus (MGN) lesions - remember this would destroy auditory sensory pathways
    • Not affected by auditory cortex leions - Conslusion: Fear Conditioning is not processed by cortex
    • Critical pathway: MGN also projects to amygdala
    • Amygdala lesion blocks fear conditioning - animals never learn to associate the tone with the shock and never elicit a conditioned response (i.e., freezing)
  28. Galvanic skin response
    measure of sympathetic nervous system activity
Card Set
PSY 241 Lecture 20
arturo zavala psychobiology drug abuse 3 emotion