Biological Bases of Behavior - Neuroscience Study Guide PDF

Unit 1: Biological Bases of Behavior Essential Question How are human thought and behavior affected by the following: The Nervous System The Endocrine System The Brain Genetics Unit 3A: Biological Bases of Behavior: Neural Processing and the Endocrine System Object...

Unit 1: Biological Bases of Behavior Essential Question How are human thought and behavior affected by the following: The Nervous System The Endocrine System The Brain Genetics Unit 3A: Biological Bases of Behavior: Neural Processing and the Endocrine System Objectives: 1. To describe the structure of neurons and explain how they communicate. 2. To discuss the nature of the nervous system. 3. To describe the endocrine system and its intimate connection to the nervous system. Unit Overview Neural Communication The Nervous System The Endocrine System Ultimate Concepts to Know: 1. Explain why psychologists are concerned with human biology, and describe the ill-fated phrenology theory. 2. Describe the parts of a neuron, and explain how its impulses are generated. 3. Describe how nerve cells communicate. 4. Describe how neurotransmitters influence behavior, and explain how drugs and other chemicals affect neurotransmission. Know This… EVERYTHING PSYCHOLOGICAL IS SIMULTANEOUSLY BIOLOGICAL!! Without your body—your genes, your brain, your appearance – you are, indeed, NOBODY  In the early 1800s… German physician Franz Gall invented phrenology: A popular but ill-fated theory that claimed BUMPS on the skull could reveal our mental abilities and our character traits. EVEN THOUGH this is NOT true, Gall was correct when he believed different parts of the brain control different aspects of behavior. Introduction Biological psychology: Branch of psychology concerned with the links between biology and behavior. Also called biopsychologist Biopsychosocial systems Biological Psychologists: They help to expand our understanding of sleep/dreams, depression and other psychological disorders, hunger and sex, stress and disease, etc….  Do-Now (Discussion) What is Biological Psychology? What parts of the body do Biological Psychologists primarily study? In understanding psychology, why do you think it is important to understand biological processes?  Biological Psychology Biological Psychology: A branch of Psychology concerned with the links between biology and behavior Biological Psychologists: Behavioral Neuroscientists Neuropsychologists Behavior Geneticists Physiological Psychologists Biopsychologists Biological Psychology  Did you Know? MOST of the research done in this unit was done on animals Neural systems between animals and humans are similar. Researchers can study squids and slugs to understand how our neural systems operate. Even though human brain is more complex, they follow the SAME principle. RATS: #1 animal used in psychological research Because rats and mice have so many biological similarities to humans, they make up 90–95% of the mammals in bio-medical research. The Nervous System  Nervous System- 2 parts Central Nervous System – Brain and Spinal Cord 99% of all nerve cells Peripheral Nervous System – Network of nerves that connects the brain and spinal cord to the other parts of the body. Brings info to and from the brain  The Central Nervous System Brain and spinal cord Neural networks: Neurons network with nearby neurons with which they can have short, fast connections. Learning occurs as feedback strengthens connections. Spinal cord: an information highway connecting the peripheral nervous system to the brain.. Neural Communication A Simple Reflex A Simple Reflex A Simple Reflex 1.RED 2.BLUE  Reflex: A simple, automatic response to a sensory stimulus, such as the knee-jerk response. Interneurons make reflexes happen: These cells in the spinal cord process motor responses quickly to protect the body from harm. Organization of the Nervous System Central Nervous System (CNS) S Sensory A Afferent M Motor E Efferent Brain & Spinal Cord The Peripheral Nervous System  The Somatic Nervous System Consists of neurons that communicate between the body and the brain Motor Neurons Neurons that carry messages from the spinal cord or brain to muscles and glands  Coordinated by The Autonomic hypothalamus Nervous System Sympathetic division Most active when you are angry, afraid, or aroused Increases heart rate and breathing Stops digestion “Fight-or-flight”  The Autonomic Nervous System Parasympathetic division Calms body Produces effects opposite to those of the sympathetic division Reduces heart rate and breathing Restores digestion “Rest and Digest” Peripheral Nervous System Summary Somatic Nervous System & Autonomic Nervous System Voluntary Involuntary Nerves connected to: Nerves connected to: Skeletal Muscles , Blood Vessels, Glands Sensory Receptors Afferent and Efferent Functions we are unaware of Autonomic Nervous System is divided into two subgroups as well: 1. Sympathetic Division – Fight or Flight (Cannon 1932) 2. Parasympathetic Division – Conserves body’s resources The Nervous System The Nervous System The Nervous System The Nervous System The Nervous System The Nervous System The Nervous System Pg. 60 Unit 3-A (A): The Neuron The Neuron Neuron: Nerve cell Basic building block of the nervous system (incoming) (Neurons within brain (outgoing) and spinal cord)  The Neuron Types of Neurons: Sensory Neurons: Carry incoming information from sensory receptors to the brain/spinal cord E.g. Perceiving something as “hot” Motor Neurons: Carry outgoing information from the brain/spinal cord to the muscles/glands E.g. Clenching a fist Interneurons: Located within the brain/spinal cord Communicate internally between sensory inputs and motor outputs E.g. Reflexes The Neuron Provide an example of information that sensory neurons may transmit. Provide an example of information that motor neurons may transmit. Provide an example of information that interneurons may transmit. Parts of the Neuron  Review What is a neuron? Differentiate between the 3 types of neurons: Sensory Neurons Motor Neurons Interneurons Discuss the functions of the following parts of the neuron: Dendrites Axon Myelin Sheath Terminal Branches What causes neurons to fire? Anatomy of Neurons Dendrite: Branching extensions of a neuron that RECEIVE messages and conduct impulses toward the cell body. (“Listens for messages”) Axon: The extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands. (“Speak the messages”)  Myelin sheath: Layer of fatty tissue encasing the fibers of many neurons; made of glia cells. Enables greater/faster transmission speed of neural impulses. Grows up to approx. age 25 Degeneration of myelin sheath: Multiple sclerosis (MS) Communication to muscle slows…eventual loss of muscle control Did you Know? Nutrients in breast milk enhances brain growth by helping to manufacture growth of myelin sheath. Studies indicated that children who were breastfed have I.Q. scores averaging seven to ten points higher than formula-fed infants. Anatomy of Neurons: Nodes of Ranvier: The spaces in between the myelin cells that encircle the axon. These spaces are important to keeping the charge going through the relatively LONG axon. Without these spaces, the charge might lose its intensity before reaching the end of the cell. LABEL your OWN Neuron: The Firing of a Neuron Neurons Neurons Neurons Neurons How does the firing of neuron work? The Firing of a Neuron Neurons transmit messages when stimulated by our senses, or triggered by chemicals of other neurons Resting Potential: Fluid interior of axon: negatively charged ions Fluid exterior of axon membrane: positively charged ions Threshold: Level of stimulation required to trigger a neural impulse (action potential) Excitatory signals (accelerator) minus inhibitory signals (brakes) must reach minimum intensity Action Potential: Neural impulse Depolarization occurs Brief electrical charge that travels down an axon “All-or-None” Response Speed of a neuron impulse Range from 2 to 200 MPH Measured in millisecond s(thousand ths of a second)  Firing of a neuron: Action potential: A neural impulse Brief electrical charge that travels down an axon. The electrical charge is due the exchange of ions, electrically charged atoms. Positively versus negatively charged Ions: Interior fluid: Negative charged ions Potassium ions Outside fluid: Positive charged ions. Sodium ions Resting potential: positive-outside/ negative- inside state. The axon surface is selectively permeable: Selective about what it allows in. EX: Resting axon has gates that block positive sodium ions.  HOWEVER, this “selective behavior” changes once an action potential fires: Axon gates open and positively charged sodium ions flood through This depolarizes the section of axon, causing axon’s next channel to open... The next….(domino effect) Sodium-Potassium Pump: Mechanism by which ions are allowed to pass through the membrane of the neural cell. Named for the two primary elements present in the ion exchange, this Sodium: pump brings positively charged sodium ions into the + ions cell and then pumps them back out when the action Potassium: potential is over. - ions  During a refractory period: Resting pause Neuron pumps the positively charged sodium ions back outside. Then, it can fire again. This entire process repeats up to 100 or even 1000 times a second. Excitatory versus inhibitory signals from other neurons: Excitatory: somewhat like pushing a neuron’s accelerator. Inhibitory: more like pushing its brake. Threshold: The level of stimulation required to trigger a neural impulse/action potential. Occurs if excitatory signal outweighs inhibitory signal. Most signals from other neurons are excitatory which can create a threshold.  All or none response: Neurons either fire or they don’t. EX: A slap (rather than a tap) will trigger MORE neurons to fire, and to fire more often. This does NOT affect the action potential's strength or speed. EX: “Squeezing a trigger harder won’t make a bullet go faster”  Similar scenario to help you understand: All-or-none law is similar to the strength of each flush. When you depress the lever, the flush is the SAME EACH TIME. Threshold: A softer push of the lever will NOT create a flush at all since it did NOT reach threshold. Refractory Period: In order to flush, the tank must be full. You cannot have two flushes occur in a row if the tank has NOT had time to fill. Action Potential Action Potential Action Potential Action Potential Action Potential https://www.youtube.com/watch?v=b2ctEsGEpe0 How do Neurons Communicate? How Neurons Communicate Synapse: The junction/gap between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. Synaptic gap/cleft: tiny gap at this junction. Less than a millionth of inch wide!!  When an action potential reaches the knoblike terminals at an axon’s end, it triggers the release of chemical messengers, called neurotransmitters. Within 1/10,000th of a second, the neurotransmitter molecules cross the synaptic gap and bind to receptor sites on the receiving neuron– as precisely as a key fits a lock. For an instant, the neurotransmitter unlocks tiny channels at the receiving site, and electrically charged atoms flow in, exciting or inhibiting the receiving neurons' readiness to fire. Then, in a process called reuptake, the sending neuron reabsorbs the excess neurotransmitters. How Neurons Communicate How Neurons Communicate How Neurons Communicate How Neurons Communicate How Neurons Communicate  How do Neurons Communicate? www.youtube.com/watch?v=LT3VKAr 4roo What Is Neurotransmission? A person reads. The words on the page enter the brain through the eyes and are converted into information that is relayed, from one neuron to the next, to regions that process visual input and attach meaning and memory. When inside neurons, the information takes the form of an electrical signal. To cross the tiny gap, or synapse, that separates one neuron from the next, the information takes the form of a chemical signal. The specialized molecules that carry the signals across the synapses are called neurotransmitters. How Neurons Communicate https://www.youtube.com/watch?v=uU_4uA6-zcE How Neurotransmitters Influence Us Acetylcholine (AcH) Dopamine Serotonin Norepinephrine GABA Glutamate Endorphins: “Morphine within”, natural opiate-like neurotransmitter linked to pain control and to pleasure; “runner’s high” Did you Know? Neurotransmitters are chemically similar to a drug or other chemical that affects behavior, cognition, and emotion. Dopamine is similar to cocaine Serotonin is similar to LSD and Ecstasy/MDMA. Marijuana causes increase in dopamine In healthy people, these chemicals are balanced to produce normal experiences. Taking illegal or non-prescribed drugs disrupts this balance, causing abnormal levels of energy, emotion, and sensory experience. Homework reading: https://www.drugabuse.gov/news-events/nida-not es/2017/03/impacts-drugs-neurotransmission https://ocw.mit.edu/ans7870/SP/SP.236/S09/lectur enotes/drugchart.htm How Neurotransmitters Influence Us: How Drugs and Other Chemicals Alter Neurotransmitters Agonists versus antagonists molecules Agonists: MIMICS Antagonists: BLOCKS Agonists and Antagonists Agonists and Antagonists Agonists and Antagonists Agonists and Antagonists  Did you Know? Curare is derived from a plant. Proun: “Cure-are-ee” Used among South American indigenous people. They would dip their blowgun darts/arrows in Curare to kill their prey.  Neuron Communication Review Myelin Sheath – speeds up transmission Terminal Button – end of axon; secretes neurotransmitters Neurotransmitters – chemical messengers Synapse – point at which neurons interconnect Hodgkin & Huxley (1952) Ions -70millivolts Action Potential All-or-None  Neurotransmitters…what are they? Specific neurotransmitters work at specific synapses Agonist – mimics neurotransmitter Antagonist – opposes action of a neurotransmitter 15 – 20 neurotransmitters known at present https://www.drugabuse.gov/news-events/nid a-notes/2017/03/impacts-drugs-neurotrans mission Unit 3A: Biological Bases of Behavior: Neural Processing and the Endocrine System  Did you Know? Endocrine means “within”. Endocrine glands secrete from within the body into the bloodstream. Endocrine System Endocrine system: The body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream. Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues. The Endocrine System Controlled by the Hypothalamus Helps coordinate and integrate complex psychological reactions Endocrine glands (organs of tissue) secrete hormones into the bloodstream Hormones are chemical substances (similar in function to neurotransmitters) that help regulate bodily activities. Pituitary gland Referred to as the “master gland” because it regulates many other glands Influences blood pressure, thirst, contractions of the uterus during childbirth, sexual behavior and interest, body growth etc. (posterior pituitary produces oxytocin)  Thyroid gland Secretes hormones (primarily thyroxin) that control metabolism How alert an energetic or how fat and thin you are Overactive Thyroid can mean insomnia, reduced attention span, agitation Too little thyroxin can mean feeling constantly tired Parathyroid glands Control levels of calcium and phosphate which in turn controls levels of excitability  Gonads Ovaries and testes secrete estrogens and androgens (testosterone) We know they play a role in sexual development, aggression and sexual drive but don’t have the whole story. Adrenal glands Secretes hormones in reaction to stress Activates (via epinephrine) the sympathetic nervous system.  Pineal gland Secretes melatonin which regulates the sleep-wake cycle Disturbances in melatonin are responsible for “jet lag” Pancreas Located under the stomach Regulates blood-sugar levels Secretes insulin and glucagon (hormones) Related to metabolism, body weight  Disorders of the Endocrine System: Diabetes (issues with blood sugar/insulin) Abnormal growth (pituitary) Hypo- and hyperthyroidism (metabolism and weight gain/loss) Hyperparathyroidism (too much calcium in blood) Including osteoporosis (weakening of the bones) and kidney stones.