Chapter 3, Biological Bases of BehaviorOverview of the nervous systemOverview of the NeuronSomaDendritesAxonMyelin sheathTerminal ButtonsSynapseTypes of neuronsNeurons do 2 things:The Neural ImpulseAll or None LawSynaptic cleft, figure 3.4NeurotransmittersAcetylcholineDopamineNorepinephrineSerotoninGABAGlutamateEndorphinsOrganization of the nervous systemhomeostasisSympathetic vs. ParasympatheticCentral Nervous SystemZe BrainHindbrainMidbrainForebrainLimbic SystemCerebrumThe Four LobesBroca’s AreaWernicke’s AreaEndocrine SystemHeredity and BehaviorChromosomesGenotype vs. PhenotypePolygenic InheritancePolygenic Inheritance cont.Behavioral GeneticsTwin Studies Twin StudiesA Hypothetical Phenotype Data ChartTwin RisksTypes of ImagingChapter 3, Biological Bases of Behavior9/17/12, 9/19/12, 9/24/12Overview of the nervous systemCommunicates in complex waysSignals are constantly being received, processed, emigrated, etc.Human behavior is explained and due to the information processing(flow chart in book)Neurons vary in size and shapeshapeContribute to neurophysiologyOverview of the NeuronFigure 3.1Somacell body, contains the nucleus, the control regionDendritesbranch-like structures that receive information or chemical messages from other neurons and send information to somaAxontransmits signal, conducts electrical/nerve impulse or action potentialMyelin sheathMADE OF GLEEL CELLS WHICH INSULATES THE AXON IN ORDER TO SPEED UP NERVE IMPULSE, NOT COMPLETELY FORMED AT BIRTH (MUSCULAR COORDINATION AND COGNITIVE FUNCTION)Terminal Buttonsknob-like structures, connected to the dendrites, which secrete neurotransmittersSynapseGAP WHICH ALLOWS THE NEUROTRANSMITTER TO LEAVE THE TERMINAL BUTTON AND ATTACH TO DENDRITESTypes of neuronsInter-neurons: communicate with other neurons, link input-output functionsSensory neurons: neuron receives signals from outside the nervous system (from sensory modalities), carry input messages from sense organs to the brainMotor neurons: carry messages from nervous system to the body’s muscles and organs, output messagesNeurons do 2 things:Help generate electricity that creates a nerve impulseRelease chemicals, or neurotransmitters, which allows for communication with other neuronsThe Neural Impulse•Figure 3.2 A &B•Outside the axon are + and – ions which dictate the resting state of the nerve•When ions are flowing in and out, there is a change in charge, facilitating the impulse•Inactive neuron is -70 millivolts•Action potential spiked by sodium channel openings, releases potassium to restore resting potential•Sodium in, potassium out•Refractory period: minimum length of time (textbook)All or None LawAction potentials occur with uniformity and maximum intensityIt either happens or does notSynaptic cleft, figure 3.4NeurotransmittersAcetylcholineDopamineNorepinephrineSerotoninGABAGlutamateEndorphinsDADAMotor function, voluntary movementMotor function, voluntary movementReward pathway, emotional arousalReward pathway, emotional arousalDysregulation linked with Parkinson’s and Dysregulation linked with Parkinson’s and Addictive disordersAddictive disordersIncrease in dopamine leads to Increase in dopamine leads to Schizophrenic disorders Schizophrenic disordersSerotoninObsessive-compulsive disordersDepressive disordersEating disordersAssociated with aggressive, regulation of sleep/wakefulness, pleasure/ painGABADysregulation linked with Anxiety disordersMain inhibitory (will not allow neural impulse) neurotransmitterGlutamateDysregulation linked with schizophreniaExcitatory (encourages neurons to be fired) neurotransmitterEndorphinsPain reliefStress responseOrganization of the nervous systemPeripheral Nervous systemMade of Somatic and autonomic nervous systemSomatic: nerves that connect voluntary skeletal muscles and voluntary sensory receptors to the central nervous system (afferent nerves: incoming) or the other direction (efferent nerves: outgoing)Autonomic: controls automatic involuntary functions like heart rate, digestion, perspiration; connects to heart, blood vessels, glands, etc.homeostasisState that our body works to maintainSympathetic vs. ParasympatheticFigure 3.8Fight or flightWhen a person is autonomically aroused, the sympathetic division speeds up in order to react (pupils dilate, bronchial passages open for more oxygen, increased heart rate, digestion inhibited, adrenaline)And then…The parasympathetic division allows homeostasis to come into play (conserve bodily resources, decreased heart rate, stimulate digestion, pupils constrict, bronchial passages close)Central Nervous SystemBrain and spinal chordProtected by cerebral spinal fluid to cushion and nourish the brainspinal chord is extension of brain which has all the connective tissuesZe BrainHindbrainMidbrainForebrainHindbrainCerebullum: coordination of movement, equilibrium, physical balance Medulla: regulates breathing, maintains muscle tonePons: regulation of sleep and arousal, role in respirationMidbrainAssociated with sensory processesVision, hearingVisual-spatial aptitudeNeurons affected by Parkinson’s released here (dopamine)Reticular formation: group of fibers that run through both the hindbrain and midbrain associated with muscle reflexes, breathing, regulation of sleep and arousalForebrainThalamus: main hub or switchboard for sensory information, relay station to cerebral cortexHypothalamus: regulates basic biological drives, the Four Fs (fighting, fleeing, feeding, and fucking), regulates hunger, thirst, linked to endocrine system and release of hormonesHPA Axis: Hypothalamus, pituitary, and adrenal axis; engaged during arousal or stress, releases cortisolLimbic System“Pleasure center”Emotion, motivation, memoryIncludes HypothalamusAmygdala: emotions, fear, aggression, sexual drive, hunger, thirst, etc.Hippocampus: involved in emotional memories and learningCerebrumLargest and most complex part of human brainHouses the cerebral hemispheres and corpus callosumCorpus callosum: bundle of fibers that pass information between the two hemispheresCerebral Cortex: intricately folded layer of cerebrum, about ¼ inch sheet of gray matter covering the outermost layer of the brainThe Four LobesFrontal: largest and most involved lobe