Neurobiological Basis Of Psychology PDF

Module 2 GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain Why isn’t the brain a nose? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview...

Module 2 GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain Why isn’t the brain a nose? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain The brain does not develop into a nose because of instructions contained in your genes. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain Genes are chains of chemicals arranged like rungs on a twisting ladder. About 20,000 to 25,000 genes that contain chemical instructions. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain These chemical instructions in the genes program the development of millions of individual parts into a complex body and brain. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain Brain’s Early Stages of Development Six-Week-Old-Brain 3 major divisions of the mature human brain. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain Brain’s Early Stages of Development Mature Brain 3 major divisions of the mature human brain. Weigh almost 3 pounds. Contain 1 trillion cells. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain What’s in your brain? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain A human brain weighs about 1,350 grams. Has pinkish-white color. Has the consistency of firm JELL-O. Fueled by sugar (glucose). Has about 1 trillion cells. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain Two Groups of Cells in the Brain The most numerous brain Glial Cells cells, about 900 billion. Neurons About 100 billion. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain Two Groups of Cells in the Brain Glial Cells The most numerous brain cells, about 900 billion. Glial Cells (astrocytes) have three functions: 1. Providing scaffolding to guide the growth of developing neurons; 2. Wrapping around neurons to form insulation to prevent interference from other electrical signals; and 3. Releasing chemicals that influence a neuron’s growth and function. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 A. Overview: Human Brain Two Groups of Cells in the Brain Neurons About 100 billion. A neuron is a brain cell with two specialized extensions. One extension is for receiving electrical signals, and the second, longer extension is for transmitting electrical signals. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function - are branchlike extensions that arise from the cell body; they receive signals from other neurons, muscles, or sense organs and pass these signals to the cell body. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function Soma (Cell body) – is a relatively large, egg-shaped structure that provides fuel, manufactures chemicals, and maintains the entire neurons in working order. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function Axon - is a single threadlike structure that extends from, and carries signals away from, the cell body to neighboring neurons, organs, or muscles. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function Myelin Sheath – looks like separate tubelike segments composed of fatty materials that wraps around and insulates an axon. It prevents interference from electrical signals generated in adjacent axon. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function Presynaptic terminals/End-bulb/terminal bulbs – look like tiny bubbles that are located at the extreme ends of the axon’s branches. Each end bulb is like a miniature container that stores chemical called neurotransmitters, which are used to communicate with the neighboring cells. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function Synapse Synapse – is an infinitely small spaces (20-30 billionths of a meter) that exists between an end bulb and its adjacent body organ (heart), muscles (head), or cell body. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function Can a brain grow new neurons? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 B. Neurons: Structure & Function Yes! But only limited number throughout adulthood. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 C. Neurons vs Nerves Nervous System Central Peripheral Nervous Nervous System System (CNS) (PNS) GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 C. Neurons vs Nerves Peripheral nervous system (PNS) is made up of nerves which are located Peripheral throughout the body except in the Nervous brain and spinal cord. System (PNS) Nerves are stringlike bundles of axons and dendrites that come from the spinal cord and are held together by connective tissue. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 C. Neurons vs Nerves Can damaged or severed limbs be reattached? Peripheral Nervous System Yes! (PNS) Because nerves can regrow, reattach or transplants are possible. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 C. Neurons vs Nerves Central The Central Nervous System is made Nervous up of neurons located in the brain and System spinal cord. (CNS) GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 D. Sending Information How does a neuron fires? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 D. Sending Information Here’s how it works: 1. RESTING POTENTIAL State: The neuron is at rest, maintaining a stable resting membrane potential of approximately -70 millivolts (mV) inside the +30 cell compared to the outside. Ion Distribution: The inside of the neuron is -55 negatively charged due to the presence of large -70 Resting potential negatively charged proteins and a higher -90 concentration of potassium ions (K+) compared to outside. Sodium ions (Na+) are more Time in milliseconds concentrated outside the neuron. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 D. Sending Information Here’s how it works: 2. THRESHOLD +30 If the depolarization is strong enough to raise the membrane potential to a specific level, -55 threshold typically around -55 mV, the threshold is Resting potential reached. This level is crucial because it triggers -70 the opening of voltage-gated sodium channels. -90 Time in milliseconds GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 D. Sending Information Here’s how it works: 3. DEPOLARIZATION Activation: If the stimulus reaches a threshold level (typically around -55 mV), voltage-gated sodium +30 on channels in the neuron's membrane open. izati olar n depNa + = i Influx of Sodium Ions: Sodium ions rush into the neuron, moving down their concentration gradient -55 threshold and causing a rapid depolarization of the membrane -70 Resting potential potential. -90 Action Potential: The membrane potential rapidly shifts from negative to positive, reaching Time in milliseconds approximately +30 mV. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 D. Sending Information Here’s how it works: 4. REPOLARIZATION Closure of Sodium Channels: Shortly after opening, sodium channels become inactive and close. +30 on K pola Re izati + = dep a = in ou rizat Opening of Potassium Channels: Voltage-gated N + olar t io potassium channels open, allowing potassium ions to -55 threshold n flow out of the neuron. -70 Resting potential -90 Restoration of Membrane Potential: Potassium efflux causes the membrane potential to return to its Time in milliseconds negative resting state. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 D. Sending Information Here’s how it works: 5. HYPERPOLARIZATION +30 on Overshoot: In some cases, potassium channels K pola Re izati + = dep a = in ou rizat N + continue to remain open briefly, causing an olar t io undershoot of the resting membrane potential -55 threshold n (hyperpolarization) before returning to baseline. -70 Resting potential Hyperpolarization -90 Time in milliseconds GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 D. Sending Information Here’s how it works: 6. REFRACTORY PERIOD In neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters What makes your heart pound? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters A transmitter is a chemical messenger that carries information between nerves and body organs, such as muscles and heart. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters What makes your brain work? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters Neurotransmitters are about a dozen different chemicals that are made by neurons and then used for communication between neurons during the performance of mental or physical activities. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters What does alcohol do? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters Alcohol (ethyl alcohol) is a psychoactive drug that is classified as a depressant, which means that it depresses the activity of the central nervous system. Alcohol molecules so closely resemble those of the GABA (gamma-aminobutyric acid) neurotransmitter that alcohol can function like GABA keys and open GABA receptors. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters What are the latest discoveries? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters Endorphins – brain’s own painkiller, very similar to morphine. They are called neurotransmitter endorphin, which is secreted to decrease pain during great bodily stress, such as an accident. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters Endorphins – brain’s own painkiller, very similar to morphine. They are called neurotransmitter endorphin, which is secreted to decrease pain during great bodily stress, such as an accident. If natural endorphins lessen pain and boost mood, why not increase this effect by flooding the brain with artificial opiates, thereby intensifying the brain’s own “feel-good” chemistry? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters DRUGS and OTHER CHEMICALS BRAIN CHEMISTRY EXCITING or INHIBITING GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters AGONIST molecules increase a neurotransmitter’s action. Some agonists may increase the production or release of neurotransmitters, or block reuptake in the synapse. What will happen if a person takes opiates drugs? Some opiate drugs are agonists and produce temporary “high” by amplifying normal sensations of arousal or pleasure. ANTAGONIST molecules decrease a neurotransmitter’s action by blocking the production or release. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters Example: Botulinium Toxin (BOTOX) treatment GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters Anandamide – Similar in chemical makeup to THC (tetrahydrocannabinol), the active ingredient in marijuana. This may help people regulate emotions, which would help them better cope with anxiety and stress. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 E. Transmitters Nitric Oxide - Regulates emotions, aggressive and impulsive behaviors. Orexin (hypocretin) - involved in the brain’s pleasure and reward system; also involved in regulating sleep and wakefulness. Low levels of this neurotransmitter have been linked to a serious sleep disorder called narcolepsy. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 F. Reflex Response Can you move without thinking? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 F. Reflex Response If you accidentally touched a hot light bulb, your hand would instantly jerk away, without any conscious thought or effort on your part. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 F. Reflex Response A reflex is an unlearned, involuntary reaction to some stimulus. The neural connections or network underlying a reflex is prewired by genetic instructions. Knee-jerk is controlled by the spinal cord. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 F. Reflex Response GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 F. Reflex Response SENSORY AFFERENT EFFERENT RECEPTORS INTERNEURON NEURON NEURON 3 TYPES OF NEURONS 1. Afferent (AFF-er-ent), or sensory, neurons carry information from the senses to the spinal cord. 2. Interneuron is a relatively short neuron whose primary task is making connections between other neurons. 3. Efferent (EFF-er-ent), or motor, neurons carry information away from the spinal cord to produce responses in various muscles and organs throughout the body. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 Activity #1: Get ¼ sheet of paper GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 Activity #1: Identify the parts 7. How do neurons communicate with other neurons or muscles? GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC  Module 2 End of Module 2 Prepare for a 20-item exam for next meeting. GENERAL PSYCHOLOGY Prepared by: Leomar Hermosilla, RGC