1. Biopsychology Chapter 3

2. Brain Basics  About the size of a grapefruit  Weighs about 3 lbs.  Has a pinkish/gray wrinkled surface  The home of some 100 billion nerve cells. Each making connections with up to 10 thousand nerve cells  Most complex structure known to man  It’s cells out number ALL the stars in the galaxy

3. Development Stages  At birth: the brain has an extra supply of nerve cells. Many die in our first few years.  Adolescence: The brain cell number stabilizes.  Adulthood: Our brains generate some new nerve cells throughout our lives, but the total remains basically constant.  New cells in our brain do expire at a low rate!  200,000, will die everyday of your adult life. But b/c we start off with so many we still have 98% of our cells at age 70!

4. Brain Capabilities  Regulates our body functions  Control over our behavior  Generates our emotions and desires  Process the experiences of a lifetime  Brain has the ability to think about itself  Brain has circuits capable of producing emotions, motives, and insights.

5. What is biopsychology?  Biopsychology  The specialty in psychology that studies the interaction of biology, behavior, and the environment  Neuroscience – Interdisciplinary field that focuses on the brain and its role in psychological processes

6. Biopsychology  How are genes and behavior linked?  Innate (inborn) abilities!  Examples of innate abilities:  At birth we are “programmed” for language, social interaction, and self preservation.  How does this happen/change?  Evolution: the process by which succeeding generations of organisms change as they adapt to a changing environment.  Ex: adapting to new diseases

7. Charles Darwin  He was originally trained for medicine and ministry. But decided biology was his calling.  1831 : signed on as a naturalist about the HMS Beagle to survey the coastline of South Africa.

8. 5 years later…  He returned from the HMS Beagle. He brought home the radical idea of relationship among species.  He observed organisms exquisitely adapt to their environments  He observed variation among individuals within species (finches beaks)

9. Natural Selection  Natural selection – The driving force behind evolution, by which the environment “selects” the fittest organisms  “Weeding out” process individuals best adapted to the environment are more likely to flourish and reproduce.  Those who don’t adapt will most likely die out.

10. How Natural Selection Works… Environmental pressure Competition Selection of fittest phenotype Reproductive success Frequency of that genotype increases

11. Evolutionary Psychology  Fairly new to the field of psychology.  It’s pretty controversial  Nature vs. Nurture. Evolutionary Psychology places too much emphasis on nature and not enough on nurture (role of learning)  It has made sense of some things:  Human phobias : they almost always involve a stimulation that signaled danger to our ancestors. (snakes, blood, darkness)

12. Genetics and Inheritance  Genes: The functional units of a chromosome  Composed of nucleotides  Chromosome: tightly coiled threadlike structure along which genes are organized. (beads on a necklace)  DNA – A long, complex molecule that encodes genetic characteristics.

13. Genes/Chromosomes

14. Genes and Inheritance  Your genes encode information that can become your inherited traits.  Your height, weight, facial features, and hair color all originate in the encoded genetic “blueprint” inherited from your parents.  Many of our psychological features are inherited from our parents as well. Like our basic temperament, fears, behavior patterns..  Who can give examples?

15. But despite genetic heritage…  You are a unique individual!  1. Your differences lie in your experiences, in the environment in which you grew up distinct to time.  2. The random combination of traits  Each parent passed onto you genes from past generations of their family lines (eye color, skin color, personality) they are combined randomly to produce you.

16. Genotype  This hybrid of genetic inheritance produces your genotype.  The genetic pattern that makes you different from everyone else. “genetic blueprint”

17. Phenotype  Your physical characteristics, including visible traits, but also the chemistry and wiring of your brain.  Examples: hair color, facial structure

18. Genes and Inheritance  Mutations – Genetic variations, which occur randomly, especially during the recombination of chromosomes in sexual reproduction

19. Heredity  How your genes are passed down.  Heredity never acts alone but always in partnership with the environment.  Example: biological influences like nutrition, diseases, and stress.  Poor medical care can result in a birth defect.

20. Chromosomes, Genes, DNA  Human makeup:  DNA contains approximately 30,000 genes  Your genes reside on 46 chromosomes that are arranged in 23 pairs.  One in each pair comes from each parent. (The genes are randomly shuffled)

21. Sex Chromosome  The X and Y chromosomes that determine our physical sex characteristics  Named “X” and “Y” for their shape  These chromosomes carry genes encoding for male or female phenotype  “X” chromosome comes from the mother  “y” chromosome comes from the father  When paired: “XX” is the phenotype for a female, “XY” is the phenotype for male  Chromosomes from the biological father determine the baby’s sex.

22. How does the body communicate internally?  The brain coordinates the body’s 2 communication systems  1. The Nervous System  2. The Endocrine System  Both systems use similar chemical processes to communicate with targets throughout the body.

23. Terms  Neurons: a cell specialized to receive, process and transmit information to other cells.  Three types: sensory, motor, interneurons

24. Sensory (afferent) Neurons  One way streets that carry traffic from the sense organs towards the brain.  They tell the brain all your sensory experiences; vision, taste hearing, touch, smell, pain, balance.

25. Motor (efferent) Neurons  One way streets that transport messages away from the brain to the muscles, organs, and glands.

26. Interneurons  Sensory and motor neurons rarely communicate directly with one another.  They rely on the interneurons, “the go between”  They relay messages from sensory neurons to other interneurons or to motor neurons.  Example: Shower: You use your hand to check the water temperature. Sensory neurons carry the sensation to the brain. Motor neurons deliver the message from the brain about the temperature.

27. Structure of a Neuron

28. Neural Impulses  Neural impulse – Brief electric surge that carries the neuron ’ s message  Ions – Charged particles that are moved across the cell membrane

29. How Neurons work:  Dendrites : finely branched fibers that extend outward from the cell body.  They accept incoming messages.  They act like a net, collecting messages received by direct stimuli,

30. How Neurons work:  Soma: Cell Body  Dendrites complete their job by passing incoming messages to the soma.  The soma contains the cell’s nucleus and accesses all the messages received/collected from the dendrites.

31. The Neural Impulse  Action Potential  Resting Potential  Synapse  Synaptic Transmission

32. How Neurons Work:  A typical neuron receives 1,000’s of messages from other neurons. But, if the messages get relayed it depends on 2 things.  1. Excitatory  fire  2. Inhibitory  Don’t fire  When excitation trumps inhibitory the neuron generates a message of its own and sends it through an axon.  Axon: is single transmitter fibers

33. Action Potential  Nerve cells employ both electrical and chemical signals to process and transmit information.  Ions: Axon gets its electrical energy to transmit information through these charged chemicals.  When the cell body becomes excited it triggers a cascade of events that temporarily reverse the charge and cause an electrical signal to race along the axon

34. Resting Potential  “Normal State” of a neuron  During this state ions within the cell give the axon a small negative charge.  *This resting potential state in-balance can be easily upset*

35. In Balance upset when…  During action potential, when the cell body becomes excited it triggers a cascade of events that temporarily reverse the charge and cause an electrical signal to race along the axon

36. Axon Principles  All or none principle:  Either the axon “fires or it doesn’t, there is no in-between.”

37. Axons-Synaptic Transmission:  Synaptic Transmission:  There is a remarkable sequence of events, the electrical message morphs into a chemical message that flows across the synaptic gap btw neurons  Synaptic Transmission  Synapse : acts as an electrical insulator, preventing the charge speeding down the axon from jumping to the next cell. (Synaptic Gap)  To pass the message across the synaptic gap a neuron must initiate a process in a tiny bulb structure  terminal buttons  Terminal buttons: are found at the ends of the axons.

38. Synaptic Vesicles (SACS)  Contain neurotransmitter molecules that connect the presynaptic membrane, releasing the neurotransmitter into the synapse.

39. Neurotransmitters  Chemical messengers that relay neural messages across the synapse.

40. 7 Important Neurotransmitter  Dopamine  Serotonin  Norepinephrine  Acetylcholine  Gaba  Glutamine  Endorphins

41. Dopamine  Produces sensations of pleasure and reward; used by CNS neurons in voluntary movement  Problems with imbalance:  Schizophrenia, Parkinson’s disease  Substances that Affect:  Cocaine, amphetamines, Ritalin, alcohol

42. Serotonin  Regulates sleep and dreaming, mood, pain, aggression, appetite and sexual behavior  Problems with imbalance:  Depression, certain anxiety disorders, obsessive-compulsive disorder  Substance that Affect:  Prozac, hallucinogenics (e.g. LSD)

43. Norepinephrine  Controls heart rate, sleep, sexual responsiveness, stress, vigilance and appetite  Problems with imbalance:  High blood pressure, depression  Substances that Affect:  Tricyclic antidepressants, beta blockers

44. Acetylcholine  Primary transmitter used by neurons carrying messages from CNS; involved in some kinds of learning and memory  Problems with imbalance:  Certain muscular disorders, Alzheimer’s disease  Substances that Affect:  Nicotine, botulism toxin, curare, atropine

45. GABA  Most prevalent inhibitory neurotransmitter in neurons of CNS  Problems with imbalance:  Anxiety, epilepsy  Substances that Affect:  Barbiturates, tranquilizers (e.g. Valium, Librium), alcohol

46. Glutamine  Primary excitatory neurotransmitter in CNS; involved in learning and memory  Problems with imbalance:  Brain damage after stroke  Substances that Affect:  PCP (“angel dust”)

47. Endorphins  Pleasurable sensations and control of pain  Problems with imbalance:  Lowered levels resulting from opiate addiction  Substances that Affect:  Opiates: opium, heroin, morphine, methadone

49. Process  1.Vesicles spill contents  2.Transmitter molecules diffuse across the synaptic gap  3.If they have the right shape of the target key receptor the message is carried forward  After the transmitter molecules have done their work, they are broken down and recycled back to the terminal buttons=REUPTAKE

51. Plasticity Neurons  Have the ability to change. They make new connections or strengthen old ones.  The nervous system has the ability to adapt or modify itself based on experience.  Example: Brains ability to compensate for injury (stroke)  “Brain is reprogrammed: by experience

52. Plasticity Neurons  Have the ability to change. They make new connections or strengthen old ones.  The nervous system has the ability to adapt or modify itself based on experience.  Example: Brains ability to compensate for injury (stroke)  “Brain is reprogrammed: by experience  http://www.youtube.com/watch?v=VaDlLD97C LM

53. Glial Cells  “Glue neurons” together!  They provide structural support for neurons, as well as help from new synapses.  Glial cells form a myelin sheath, a fatty insulation around the spinal cord and axons in the brain.  Protects the cell and helps speed the conduction of impulses along the axon.  MS attacks the myelin sheath