OUTLINE Chapter 3 Mod 7 8 9 NEUROSCIENCE BEHAVIOR 1 Neurons and Neural communication a Neurons neural impulses b Neural communication c Neurotransmitters 2 Nervous system a Structure and function b Reflexes vs Neural networks 3 The Brain a Studying the brain b Brain regions function c Plasticity d Hemispheric differences Gazzaniga article video NEURONS STRUCTURE Dendrite the in box it receives signals from Cell body basic cell functions Axon the out box axon away sends signals to o Other neurons o Effector cells muscles Myelin Sheath a fatty substance that encases the axon of some cells o Increases the speed of transmission Terminal Vesicles axon terminals store and eventually releases enzyme called neurotransmitters The neurotransmitters are released into the synapse Synapses a small space between the axons of one cell and the dendrites of the next cell Receptor Sites locations on the dendrite of the next neuron neurotransmitters bind to receptor sites and the whole process begins anew NEURONS COMMUNICATION How do neurons communicate 1 How does information travel within a neuron 2 How is information passed from one neuron to the next NEURONS communication WITHIN ACTION POTENTIAL 1 All neurons have a resting state 70 mv Has more negative ions than positive ions 2 Dendrite is stimulated Positive ions flow into the cell until 3 Threshold is reached 65 mv Action potential is triggered all or nothing because it is a little bit more positive than at resting state 4 Wave moves down the axon happens immediately 5 Wave reaches the terminal vesicles NEURONS communication BETWEEN 5 Wave reaches the terminal vesicles 6 Neurotransmitters NTs are released into the synapse 7 NTs bind with receptors on dendrite of next neuron 8 Process starts in the next cell NTs can Excite the next neuron Inhibit the next neuron Refractory period again Brief period when the neuron is unable to fire o Reuptake occurs excess NTs are taken back for reuse in the axon of the neuron to release then o Axon returns to resting state at 70 mv NEUROTRANSMITTERS Acetylcholine Needed for movement learning and memory Alzheimer s patients have too little Blocking acetylcholine causes paralysis Endorphins Nature s pain reliever Eating chocolate athletics stress Serotonin Affects mood sleep hunger arousal Low levels of serotonin causes depression and anxiety Prozac increases serotonin levels Dopamine Related to movement learning attention emotion o Too much schizophrenia o Too little Parkinson s Disease Hard to get a balance because if prescribed too much causes schizophrenia or not prescribed enough causes Parkinson s GABA Eating sleeping Inhibitory rather than excitatory DRUGS effect on neural communication Drugs can have two effects 1 Agonists the enhancer mimic the action of the NT Binds a NT site receptor site Blocks reuptake of NT leaving more Counteracts enzymes that clean out synapses 2 Antagonists the blocker block the action of the NT Blocks NT sties Destroys NT leaving less Decreases effectiveness of the NT NERVOUS SYSTEM TYPES OF NEURONS 1 Sensory Neurons Afferent From the body towards the brain Specialized for different sensations 2 Motor Neurons Efferent From the brain back to the body 3 Interneurons Does the communication between sensory neurons and motor neurons Example Mosquito lands on your arm Sensory Neurons body feels bug on arm so sensory neurons tell brain that there is something itch on your arm Motor Neurons brain tells body to swat the bug off your arm CENTRAL NERVOUS SYSTEM SPINAL CORD Certain emergency messages very fast response Q How A Reflexes Skip the brain Info is fed up and down the spinal cord only o Fast response o Poor motor control Ex Step on something in the middle of the night 1 Draw back foot 2 Feeling pain 3 Identify roommate s junk on floor CENTRAL NERVOUS SYSTEM BRAIN Connection between brain and behavior What does what Early Theory PHRENOLOGY Does size matter What is it Tried to relate behavior to bumps on the skull If you have a lot of bumps you have more of a certain trait brain power If you have small little bumps you have less of a certain trait Problems with Phrenology Shape of the brain and skull does not always match It was difficult to falsify Couldn t see the brain CURRENT TECHNIQUES Neuroimaging X ray of your brain Good to see the picture of the brain but not CAT scan activity MRI Bombard your brain with radio waves which affects the naturally occurring magnetic field of your brain Active areas produce different magnetic fields than inactive areas PET scan glow Inject with radioactive glucose Active area in the brain use the glucose and BRAIN STRUCTURE AND FUNCTION Region BRAINSTEM medulla oblongata pons reticular formation cerebellum little brain Associated Behavior breathing heart rate etc pathway from spinal cord to higher brain sleep wake arousal coordination movement balance thalamus hypothalamus switchboards for the brain limbic system amygdala hippocampus Cerebral Cortex emotion memory sensation movement and all higher order behaviors BRAIN CEREBRAL CORTEX strategic behavior helps to organize plan FRONTAL LOBES Functions and strategize emotional behavior o Ex Phinneus Gage Contains the Motor Cortex Sends information out to the body Related to movement Receives incoming information Related to sensation PARIETAL LOBE Contains the Sensory Cortex OCCIPITAL LOBE Functions vision TEMPORAL LOBE Functions auditory behavior language memory BRAIN WHAT DOES WHAT Localization of function Reading a written word involves all of the following 1 retina 2 optic nerve 3 through diencephalon LGN 4 visual cortex parietal lobe 5 Temporal lobe 6 Wernicke s Area comprehension 7 Broca s Area speaking 8 Motor Cortex 9 Lungs vocal cords mouth lips etc 10 Auditory system becomes activated provides feedback BRAIN FUNCTION Hemispheric Differences Left Hemisphere logic speech analytical Right Hemisphere emotion music artistic Corpus Collosum membrane that connects divides halves Left favors tasks that require analytical processing Right favors tasks that require holistic artistic processing E E E E E E EEEEEEEEE E E E E E E more right hemisphere activity if asked to name H more left hemisphere activity if asked to name E SPLIT BRAINS NORMAL Division of labor works very nicely IN ALL OF US Left side of the brain right side of body Right side of the brain left side of the body Left visual field is processed by right hemisphere and Left and right sides of brain can communicate with vice versa
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