1. 1 Neuroscience and Behavior Chapter 3

2. 2 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

3. 3 Evolution has fundamentally shaped psychological processes because it favors genetic variations that produce adaptive behavior How Are Genes and Behavior Linked?

4. 4 Innate – Inborn; present at birth; part of the organism’s biological heritage Evolution – The gradual process of biological change that occurs in a species as it adapts to its environment

5. 5 Evolution and Natural Selection Natural selection – The driving force behind evolution by which the environment “selects” the fittest organisms

6. 6 How Natural Selection Works Environmental pressure (changes in the environment) Competition (for resources) Selection of fittest phenotype (from among a variety of phenotypes) Reproductive success (genotype corresponding to fittest phenotypes passed to next generation) Frequency of that genotype increases (in next generation)

7. 7 Genes and Inheritance Genotype – An organism’s genetic makeup Phenotype – An organism’s observable physical characteristics

8. 8 Genes and Inheritance Mutations – Genetic variations, which occur randomly, especially during the recombination of chromosomes in sexual reproduction

9. 9 Chromosomes, Genes, and DNA DNA – A long, complex molecule that encodes genetic characteristics Genes – The functional units of a chromosome –Composed of nucleotides

10. 10 Sex chromosomes – The X and Y chromosomes that determine our physical sex characteristics Genes influence our psychological characteristics as well as our physical traits Chromosomes, Genes, and DNA Chromosomes – Tightly coiled threadlike structures along which the genes are organized

11. 11 History of Mind Plato correctly placed mind in the brain. However, his student Aristotle believed that mind was in the heart. Ancient Conceptions About Mind Today we believe mind and brain are faces of the same coin. Everything that is psychological is simultaneously biological.

12. 12 History of Mind In 1800, Franz Gall suggested that bumps of the skull represented mental abilities. His theory, though incorrect, nevertheless proposed that different mental abilities were modular. Phrenology Bettman/ Corbis

13. 13 The body’s two communication systems, the nervous system and the endocrine system, both use chemical messengers to communicate with targets throughout the body How Does the Body Communicate Internally?

14. 14 The Neuron Types of Neurons –Sensory neurons (carry msgs from sense receptors towards the CNS) Motor neurons (carry msgs from CNS toward muscles & glands) Interneurons (carry msgs b/w nerve cells)

15. 15 Neural Communication The body’s information system is built from billions of interconnected cells called neurons.

16. 16 Neural Communication We are a biopsychosocial system. Cellular Level (Interconnected Neurons) Organ Level (Brain) System Level (Information Processing) Individual Level (Human Being) Group Level (Family) Ethnic Level (Culture) Community Level (Society)

17. 17 Neural Communication Note the similarities in the above brain regions, which are all engaged in information processing. Neurobiologists and other investigators understand that humans and animals operate similarly when processing information.

18. 18 Neuron A nerve cell, or a neuron, consists of many different parts.

19. 19 Action Potential A neural impulse. A brief electrical charge that travels down an axon and is generated by the movement of positively charged atoms in and out of channels in the axon’s membrane.

20. 20 Depolarization & Hyperpolarization Depolarization: Depolarization occurs when positive ions enter the neuron, making it more prone to firing an action potential. Hyperpolarization occurs when negative ions enter the neuron, making it less prone to firing an action potential.

21. 21 Threshold Threshold: Each neuron receives depolarizing and hyperpolarizing currents from many neurons. When the depolarizing current (positive ions) minus the hyperpolarizing current (negative ions) exceed minimum intensity (threshold) the neuron fires an action potential.

22. 22 Refractory Period & Pumps Refractory Period: After a neuron fires an action potential it pauses for a short period to recharge itself to fire again. Sodium-Potassium Pumps: Sodium-potassium pumps pump positive ions out from the inside of the neuron, making them ready for another action potential.

23. 23 Action Potential Properties All-or-None Response: When the depolarizing current exceeds the threshold, a neuron will fire. If the depolarizing current fails to exceed the threshold, a neuron will not fire. Intensity of an action potential remains the same throughout the length of the axon.

24. 24 Synapse Synapse [SIN-aps] a junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. This tiny gap is called the synaptic gap or cleft.

25. 25 Neurotransmitters Neurotransmitters (chemicals) released from the sending neuron travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing it to generate an action potential.

26. 26 Reuptake Neurotransmitters in the synapse are reabsorbed into the sending neurons through the process of reuptake. This process applies the brakes on neurotransmitter action.

27. 27 Lock & Key Mechanism Neurotransmitters bind to the receptors of the receiving neuron in a key-lock mechanism.

28. 28 Agonists Ex: Beta Blockers (used to treat high bp, glaucoma, migraines)

29. 29 Antagonists Ex: Nicotine

30. 30 Neurotransmitters

31. 31 7 Important NTsDopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins

32. 32 NeurotransmittersDopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: 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

33. 33 Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Regulates sleep and dreaming, mood, pain, aggression, appetite and sexual behavior Problems with Imbalance: Depression, certain anxiety disorders, obsessive- compulsive disorder Substances that Affect: Prozac, hallucinogenics (e.g. LSD)

34. 34 Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Controls heart rate, sleep, sexual responsiveness, stress, vigilance and appetite Problems with Imbalance: High blood pressure, depression Substances that Affect: Tricyclic antidepressants, beta blockers

35. 35 Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Primary transmitter used by neurons carrying messages from CNS; involved in some kinds of learning and memory; involved in muscle movements Problems with Imbalance: Certain muscular disorders, Alzheimer’s disease Substances that Affect: Nicotine, botulism toxin, curare, atropine

36. 36 Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Most prevalent inhibitory neurotransmitter in neurons of CNS Problems with Imbalance: Anxiety, epilepsy Substances that Affect: Barbiturates, tranquilizers (e.g. Valium, Librium), alcohol

37. 37 Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Primary excitatory neurotransmitter in CNS; involved in learning and memory Problems with Imbalance: Brain damage after stroke Substances that Affect: PCP (“angel dust”)

38. 38 Neurotransmitter s Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Pleasurable sensations and control of pain Problems with Imbalance: Lowered levels resulting from opiate addiction Substances that Affect: Opiates: opium, heroin, morphine, methadone

39. 39 Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS)

40. 40 The Nervous System Nervous System: Consists of all the nerve cells. It is the body’s speedy, electrochemical communication system. Central Nervous System (CNS): the brain and spinal cord. Peripheral Nervous System (PNS): the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

41. 41 The Nervous System

42. 42 Kinds of Neurons Sensory Neurons carry incoming information from the sense receptors to the CNS. Motor Neurons carry outgoing information from the CNS to muscles and glands. Interneurons connect the two neurons. Sensory Neuron (Bipolar) Interneuron Neuron (Unipolar) Motor Neuron (Multipolar)

43. 43 Glial Cells Provide structural support for neurons Help in forming new synapses Form myelin sheath

44. 44 Peripheral Nervous System (PNS) Somatic Nervous System: controls the body’s skeletal muscles (voluntary activities). such as climbing the stairs. Autonomic Nervous System: controls the glands & other muscles (involuntary activities)  Heartbeat, pupil dilation, breathing, etc.

45. 45 The Nerves Nerves consist of neural “cables” containing many axons. They are part of the peripheral nervous system and connect muscles, glands, and sense organs to the central nervous system.

46. 46 Autonomic Nervous System (ANS) Sympathetic Nervous System: Division of the ANS that arouses the body, mobilizing its energy in stressful situations. Parasympathetic Nervous System: Division of the ANS that calms the body, conserving its energy.

47. 47 Autonomic Nervous System (ANS) Sympathetic NS “Arouses” (fight-or-flight) Parasympathetic NS “Calms” (rest and digest)

48. 48 ANS Sympathetic –Increases blood pressure –Suspends digestion –(expends energy)

49. 49 ANS Parasympathetic (calming) –Works to conserve energy & to enhance the body’s ability to recover from strenuous activity –Reduces heart rate

50. 50 ANS Parasympathetic –Reduces bp –Brings body back to resting state –(conserves energy)

51. 51 The Endocrine System The Endocrine System is the body’s “slow” chemical communication system. Communication is carried out by hormones synthesized by a set of glands.

52. 52 Hormones Hormones are chemicals synthesized by the endocrine glands that are secreted in the bloodstream. Hormones affect the brain and many other tissues of the body. For example, epinephrine (adrenaline) increases heart rate, blood pressure, blood sugar and feelings of excitement during emergency situations.

53. 53 Pituitary Gland Is called the “master gland.” The anterior pituitary lobe releases hormones that regulate other glands. The posterior lobe regulates water and salt balance.

54. 54 Thyroid & Parathyroid Glands Regulate metabolic and calcium rate.

55. 55 Adrenal Glands Adrenal glands consist of the adrenal medulla and the cortex. The medulla secretes hormones (epinephrine/adrenaline & norepinephrine/nor- adrenaline) during stressful and emotional situations, while the adrenal cortex regulates salt and carbohydrate metabolism.

56. 56 Gonads Sex glands are located in different places in men and women. They regulate bodily development and maintain reproductive organs in adults.