Neurons, Hormones, and the Brain An Invitation to Psychology Second Edition Carole Wade Carole Tavris

1. Neurons, Hormones, and the BrainAn Invitation to PsychologySecond EditionCarole WadeCarole Tavris Porterville College Psychology 101 Online Norris Edwards

2. Neurons, Hormones and the Brain • When celebrities like Michael J. Foxx or Christopher Reeves is stricken with a neurological disorders or injuries, it reminds us all how complex and sensitive our nervous systems truly are.

3. The Nervous System: A Basic Blueprint ~Divisions of the Nervous System • Central Nervous System • Brain • Spinal cord • Peripheral Nervous System • Somatic • Autonomic

4. The Peripheral Nervous System • Contains all portions of the nervous system out side the brain and spinal cord. • It is the means by which our brains collect information about the outside world. • Comprised of two types of nerves: • Sensory Nerves • Motor Nerves.

5. The Autonomic Nervous System • The Autonomic Nervous System Is Divided Into Two Parts: • The Sympathetic Nervous System • The Subdivision of the Autonomic Nervous System That Mobilizes Bodily Resources and Increase the Output of Energy During Emotion and Stress. • “The Fight or Flight Reaction” • The Parasympathetic Nervous System • The Subdivision of the Autonomic Nervous System That Operates During Relaxed States and That Conserves Energy.

6. The Autonomic Nervous System • Even though we say that the action of the autonomic nervous system are automatic we can learn to heighten or suppress our autonomic responses.

7. The Autonomic Nervous System and Yoga • Many yogis have learn to master their autonomic responses in order to • Slow their heart rates • Reduce their metabolic rates • Reduce the respiration rates

8. The Autonomic Nervous System and Biofeedback • Neal Miller has demonstrated we can learn to control their visceral response by using a technique called biofeedback (Miller et. al. 1978) to • Control their blood pressure • Control their blood flow • Control their heart rates • Control their skin temperature

9. Nervous System ______ Nervous System ______ Nervous System Brain Spinal Cord ______ Nervous System Autonomic Nervous System ______ Nervous System ______ Nervous System Quick Quiz – Let’s Test You Recollection of the CNS Fill in the Blanks

10. Nervous System Central Nervous System Processes, interprets, & Stores information,issues Orders to muscles, organs Peripheral Nervous System Transmits information to And from the CNS Brain Spinal Cord Somatic Nervous System Controls Skeletal Muscles Autonomic Nervous System Regulates glands Blood vessels etc. So, How Did You Do? Sympathetic Nervous System Mobilizes body for Action, energy Output Parasympathetic Nervous System Conserves energy Maintains quiet state

11. Communication in the Nervous System • The Nervous System Is Made up in Part of Neurons or Nerve Cells • A Cell That Conducts Electro-chemical Signals, the Basic Unit of the Nervous System. • The Neurons Are Held in Glial Cells (Greek for “Glue”) • Nervous System Cell That Aid the Neurons by Providing Them With Nutrients, Insulations, and Removing Cellular Debris When They Die.

12. The Structure of The Neuron • The Neuron has three main parts: • Dendrite • Cell Body • Axon • Myelin Sheath • Nerve

13. The Structure of the Neuron • Until recently neuroscientist thought that neurons in the CNS could not reproduce or regenerate themselves. • Based upon this assumption physical injuries to the spine were assumed to be more or less permanent.

14. The Structure of the Neuron • Schnell & Schwab in 1990, however, demonstrated in animal studies that severed axons in the spinal cord card regrow in treated with certain nervous-system chemicals. • Reynolds & Weiss, 1992 demonstrated that immature cells (precursor cells will give birth to new neurons neurogenesis), when immerse in growth-promoting protein.

15. The Structure of the Neuron • We know that human brain also contains precursor cells (progenitor or stem cells) • Areas associated with learning and memory continue to divide and mature throughout adulthood (Gage et.al. 1998) • Physical and mental exercise promote the production and survival of new cells (Gould et. Al., 1999)

16. How Neurons Communicate • Axon terminals release neurotransmitter • Neurotransmitter enters synaptic gap • Neurotransmitter binds to receptors that it fits

17. The Synapse

18. Stimulation and Synaptic Development • This plasticity of the nervous system may account for how stoke victims by recover the use of a limb, due to the brains rewiring or adapting to the damage. • Recent research with stroke patients has supported this view. (Liepert et. al., 2000)

19. The Action Potential

20. The Synapse and Neurotransmitters

21. Lock & Key Neurotransmitters

22. Chemical Messengers in the Nervous System • Neurotransmitter • A chemical substance that is released by a transmitting neuron at the synapse and that alters the activity of a receiving neuron. • There are literally hundreds of substances in the body who are known or suspected to be neurotransmitters.

23. Major Neurotransmitters • Acetylcholine (ACh) • Dopamine • Serotonin • Endorphins • Norepinephrine • Gamma amino butryic acid (GABA)

24. Opioids and Substance P

25. The Endocrine System • Endocrine glands release hormones into the bloodstream • Hormones regulate growth, metabolism, sexual development and behavior, and other functions

26. Hormones: Melatonin • A hormone secreted by the pineal gland that is involved in the regulation of daily biological rhythm. • Promotes sleep and helps to regulate the 24 hour wake-sleep cycle (Haimov & Lavie, 1996-

27. Hormones: Adrenal Hormones • Hormones that are produced by the adrenal glands and that are involved in emotion and stress. • Cortisol increases blood sugar levels and boost energy. • Epinephrine (adrenaline) and Norepinephrine activates the sympathetic nervous system.

28. Hormones: Sex Hormones • Hormones that regulate the development and functioning of reproductive organs and that stimulate the development of male and female sexual characteristics; including androgens, estrogens, and progesterone.

29. Electroencephalogram

30. Positron Emission Tomography • PET Scan (Positron - Emission Topography • A method for analyzing biochemical activity in the brain, using injections of a glucose-like substance containing a radioactive element.

31. Magnetic Resonance Imaging • Magnetic fields align certain ions and compounds • When field is removed, these molecules release energy as radio waves • Computer calculates tissue density from radio waves • Provides clear, 3D images

32. A Tour Through the Brain • All modern brain theories assume that different parts of the brain perform different although overlapping functions. • This concept is know and localization • The concept was first proposed by Joseph Gall (1758-1828) as part of his theory of phrenology.

33. Brainstem • The part of the brain at the top of the spinal cord, consisting of the medulla, the pons and the reticular activating system (RAS).

35. Limbic System • A group of brain areas involved in emotional reactions and motivated behaviors, including • The Amygdala • The Hippocampus

36. Lobes of the Cerebral Cortex

37. Lobes of the Cerebral Cortex

38. Cerebral Cortex in Animals

39. Comparative Neuroanatomy • The cerebral cortex (roughly 3 millimeters thick) accounts for three fourths of the cells in our brain. • Notice the relative size of our cerebral cortex when compared to other animals.

40. The Strange Case of Phineas Gage • Gage was a railroad construction foreman • An 1848 explosion forced a steel tamping rod through his head • Others said he was “…no longer Gage…” • Lost his job, worked as a sideshow exhibit

41. Phineas Gage • Gage was treated with such skill by Cavendish physician Dr. John Harlow that he returned to his home In 1867, Gage's body was exhumed from San Francisco. The skull and tamping iron were delivered to Dr. Harlow. Harlow reported his findings, including his estimate of the brain damage, in 1868. • his case had an influence on the science of localization of brain function.

42. The Corpus Callosum • Millions of myelinated axons connecting the brain’s hemispheres • Provides a pathway for communication between the hemispheres • If surgically severed for treatment of epilepsy, hemispheres cannot communicate directly

43. Sperry’s Split-Brain Experiment • Split-brain subjects could not name objects shown only to the right hemisphere • If asked to select these objects with their left hand, they succeeded • The right side of the brain doesn’t control speech

44. Visual Processing • Both eyes send information to both hemispheres • Right half of the visual field goes to the right hemisphere • Left half of the visual field goes to the left hemisphere

45. Right-Handed Objects • Many common objects are designed for right-handed use • Left-handers often must put their hands into awkward or dangerous positions to use them

46. Left Hemisphere Right-handed people and the majority of left-handed persons process language mainly in the left hemisphere (Springer & Deutch 1998) More active in logical, symbolic, and sequential tasks For these reason referred to as Dominant. Right Hemisphere Superior in spatial-visual abilities e.g. Maps, facial recognition. Cognitive style intuitive and holistic Contains the regions that process negative emotions e.g. fear, sadness and the tendency to withdraw (Davidson, 1995) A Question of Dominance

47. The Talking Left Hemisphere • Brighter areas indicate higher activity levels • During hearing words, for example, auditory cortex and Wernicke’s area are most active

48. Left-Handedness Across the Life Span • Proportion of left handers drops with age • 15% of 10-year-olds • 5% of 50-year-olds • < 1% of 80-year-olds • Cause is unknown • Longevity hypothesis • Modification hypothesis

49. Why Do We Dream? • One possible function of dreams and sleep is to allow the body with a time-out period. • To allow the body time to eliminate waste products, repair cells, and strengthen the immune system. • Another thought is that dreams help the brain function efficiently. • Chronic sleep deprivation, results in higher level of Cortisol which may damage or impair brain cell (Leproult et.al., 1997)

50. The Realms of Sleep • Nathaniel Kleitman and Eugene Aserinsky (1955) • Using an electroencephalograph measured the brain activity of sleeping subject to explain the variation in eye movement during sleep. • Correlated with changes in brain wave patterns.