Chapter 3: Neuroscience and Behavior The McGraw-Hill Companies, Inc.

Transcription

1 Chapter 3: Neuroscience and Behavior

2 Parts for study Nervous system Brain Endocrine system Behavior hereditary and evolutionary

3 Neurons: The Basic Elements of Behavior From Neurons to Nervous System: The Biology Underlying Behavior Your nervous system is living tissue composed of cells. Divided into neurons and glia

4 Neuron: Basic Structure Dendrites Receive message s from other neurons

5 Neuron: Basic Structure Axon- Carries messages destined for other cells Myelin Sheath- Wrapped around the axon, a protective coating Soma- cell body

6 Neuron: Basic Structure All-or-none law Neurons are either on or off Resting state Negative electrical charge within a neuron Action potential An electric nerve impulse that travels through a neuron, changing the cell s charge from negative to positive

7 Neuron: Basic Structure

8 Neural impulses Hodgkin and Huxley study- find out what this impulse was (p.75) Squid axons, inserted microelectrodes, What did they find out? Ions are present outside of neuron, pos and neg travel across cell membrane at diff times, Cell is resting, stable- negative charge When stimulated, positive sodium ions sent in and actions potential happens. Refractory period lasts seconds, when another action potential cannot take place.

9 Neuron continued Neurotransmitters- chemicals that are secreted from the Terminal buttons Terminal buttons are clusters at end of axon Neurons vary in size and shape Glia- glue, support cells, outnumber neurons 10-1, nourish, eliminate waste, unsung heroes, new research shows they can communicate as well.

10 Neuron: Basic Structure Excitatory messages A chemical secretion that makes it more likely that a receiving neuron will fire and an action potential will travel down its axon Inhibitory messages A chemical secretion that prevents a receiving neuron from firing

11 Neuron: Basic Structure Neurotransmitters Chemicals that carry messages across the synapse to the dendrite (and sometimes to the cell body) of a receiver neuron Synapse A chemical connections that bridges the gap between two neurons

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13 Neuron: Basic Structure Acetylcholine (Ach) Location Brain, spinal cord, peripheral nervous system, especially some of the organs of the parasympathetic nervous system Effect Excitatory in brain and autonomic nervous system; inhibitory elsewhere Function Muscle movement, cognitive functioning Acetylcholine (ACh)

14 Neuron: Basic Structure Glutamate Location Brain and spinal cord Effect Excitatory Function Memory Glutamate

15 Neuron: Basic Structure Gamma-amino butyric acid (GABA) Location Brain and spinal cord Effect Main inhibitory neurotransmitter Function Eating, aggression, sleeping Gamma-amino butyric acid (GABA)

16 Neuron: Basic Structure Monamines( also noreph. and serotonin) Dopamine Location Brain Effect Inhibitory or excitatory Function Muscle disorders, mental disorders, Parkinson s disease Dopamine

17 Neuron: Basic Structure Serotonin Location Brain and spinal cord Effect Inhibitory Function Sleeping, eating, mood, pain, depression Serotonin

18 Neuron: Basic Structure Endorphins Location Brain, spinal cord Effect Primarily inhibitory, except in hippocampus Function Pain suppression, pleasurable feelings, appetites, placebos Endorphins

19 Neurotransmitters

20 The Nervous System and the Endocrine System

21 Central and Peripheral Nervous Systems

22 Central Nervous System Spinal Cord Reflexes Sensory (Afferent) Neurons Motor (Efferent) Neurons Interneurons

23 Nervous system Includes brain Org: 110 billion neur. in brain= 100 trillion synapses Divided into CNS and peripheral CNS includes brain and spinal cord Peripheral is divided into 2 sections: Somatic autonomic

24 Peripheral Nervous System Somatic division Controls voluntary movement Autonomic division Controls that parts of the body that keep us alive the heart, blood vessels, glands, lungs, etc.

25 Peripheral continued Somatic- skeletal muscles and sensory organs Includes cables to and from muscles to CNS Afferent nerves Efferent nerves

26 Peripheral Nervous System

27 CNS Brain and Spinal cord Brain- integrator Spinal cord- big long axon

28 Evolutionary Foundations of The Nervous System Evolutionary Psychology The branch of psychology that seeks to identify behavior patterns that are a result of our genetic inheritance from our ancestors Behavioral Genetics The study of the effects of heredity on behavior

29 The Endocrine System Endocrine system Sends messages throughout the nervous system Hormones Affect the functioning or growth of other parts of the body Pituitary gland The master gland

30 The Endocrine System

31 The Brain

32 Spying On the Brain: Research Methods Electroencephalogram (EEG) Computerized Axial Tomography (CAT) Scan Positron Emission Tomography (PET) Scan Functional Magnetic Resonance Imaging (fmri) Transcranial Magnetic Stimulation (TMS)

33 Spying On the Brain: Research Methods Advances in brain imaging also have given rise to neuroforensics, the application of brain science, behavioral genetics, and neural imaging to legal questions

34 Spying On the Brain: Research Methods be sure to know different technology

35 The Old Brain Central core Controls basic functions like eating and sleeping Medulla Pons Reticular Formation

36 The Old Brain Central core Cerebellum Controls balance Thalamus Relay station for information concerning senses Hypothalamus Maintains homeostasis and produces vital basic behavior

37 The Limbic System: Beyond the Central Core Part of the brain that controls eating, aggression, and reproduction Amygdala Hippocampus Fornix

38 Peripheral cont d Autonomic Heart, blood vessels, glands Heart rate, physiological arousal Cannon study Divided into sympa and para

39 The New Brain Cerebral cortex Responsible for the most sophisticated information processing in the brain 4 Lobes Association (Speech) areas Aphasia Broca s area Wernicke s area

40 The New Brain Motor area Responsible for voluntary movements of particular parts of the body Sensory area Somatosensory area Auditory area Visual area

41 Mending the Brain Regeneration of neurons Stem cell research Neuroplasticity Changes in the brain that occur throughout the life span relating to the addition of new neurons, new interconnections between neurons, and the reorganization or informationprocessing areas

42 The Specialization of the Hemispheres Hemispheres Two symmetrical left and right halves of the brain that control the side of the body opposite to their location Lateralization The dominance of one hemisphere of the brain in specific functions

43 The Split Brain: Exploring the Two Hemispheres Surgically cutting the corpus callosum Split brain patients A person who suffers from independent functioning of the two halves of the brain Biofeedback Procedure in which a person learns to control through conscious thought internal physiological processes such as blood pressure, heart and respiration rate, skin temperature, sweating, and the constriction of muscles

44 Biology and behavior Reminder that the endocrine system plays a role: hormones that affect our processing and behaviors, include Pituitary- mater gland Adrenal- fight or flight( Cannon study) Pineal- wake sleep cycles Thyroid-metabolism Pancreas insulin Ovaries and testes estrogen and testosterone Genetics and heredity: Chromosomes- are DNA strands, 23 pairs Genes are DNA segments, also operate in pairs, one dominant and one recessive, child has 50 % probability of inheriting a gene from parent Genotype- our blueprint Phenotype- our appearance Abnormalities include downs Syndrome, Huntington s disease and Turners Syndrome Our traits are influences by more than one gene- Polygenic traits, so hard to predict certain behaviors since it can come from many different areas. Family and twin studies assist with figuring it out Genetic mapping documents genetic sequences, does not reveal how genes govern behavior but hope to understand in future issues such as schizo, personality traits etc Heredity and role of environment is studied- Plomin 2004 jointly influences behavior but to what degree of vulnerability?

45 Evolutionary Darwin s ideas had great influence early on( as did others) Noted that some of our characteristics are heritable, looked into why a species survives Reproductive fitness Natural selection Modern models: Adaptation- inherited characteristics that increased in a population bc it helped survival Behavior as an adaptive trait: learned beh that increase our reproductive success, seen in animals and humans, ex on p. 109 in text