PBIOPSY: BIOLOGICAL PSYCHOLOGY REVIEWER FOR PRELIMINARY EXAMINATION LESSON 1: INTRODUCTION TO BIOLOGICAL PSYCHOLOGY Biopsychology - scientific study of the biology of behavior developed as a major neuroscience discipline in the 20th century a healthy and rapidly growing infant its topics explore sleep to sexuality, emotions to learning, and hunger to psychopathology an integrative discipline in that it draws together other neuroscientific disciplines 6 Fields of Neuroscience Relevant to Biopsychology Inquiry 1. 2. 3. 4. 5. 6. Neuroanatomy Neuroendocrinology Neurochemistry Neuropathology Neuropharmacology Neurophysiology TYPES OF RESEARCH THAT CHARACTERIZED BIOLOGICAL APPROACH 1. Human vs. Nonhuman Experiment - the subject of biopsychological research (human and nonhuman animals) mice and rats are the most common subjects used in nonhumans A. Human Participant Guidelines - coercion of people to participate in the study is unacceptable - participants must be informed that they can leave the experiment t any point in time without penalty - participant must be provided with informed consent B. Nonhuman Participant Guidelines - first provision: animal research should have a clear scientific purpose such as increasing our knowledge of behavior or improving the health and welfare of humans or other animals (American Psychological Association, 2008) - second provision: basic care and housing of the animals - final: experimental procedures should cause as little pain and distress as possible 2. Experiment vs. Non-Experiment A. Experiment - method used to study causation to find out what causes what - designs two or more conditions under which the living subjects will be tested experimenter assigns the subjects to conditions, administers the treatments, and measures the outcome in such a way that there is only one relevant difference between the conditions being compared B. Quasi-experimental Studies - studies group of subjects who have already been exposed to the conditions of interest in the real world - e.g., alcoholics, which in this case, experimenters no longer have to assign the subjects to a condition that involves years of alcoholism, or in other cases, to unethically instigate irreversible damage to the brain - technically not an experiment because participants themselves decided which group they would be in, by drinking alcohol or not, whereas the researchers had no means of ensuring that exposure to alcohol was the only variable that distinguished the two groups C. Case Studies - focus on a single case or subject - problem: generalizability—degree to which the results can be applied to other cases 3. Pure and Applied Research A. Pure Research - motivated primarily by the curiosity of the researcher - done solely for the purpose of acquiring knowledge B. Applied Research - intended to bring about some direct benefit to humankind RESEARCH METHODS IN BIOLOGICAL PSYCHOLOGY 1. Histology - study of microscopic structures and tissues ❖ Anton Van Leeuwenhoek - conducted the first investigation of nerve tissue under a microscope in 1674 - it was only during the 1800 when there has been a clearer microscopic lens ❖ tissue to be studied under the microscope must be 1) prepared for viewing in a series of steps; and 2) made thin enough to allow light to pass through it ❖ microtome - special machine used to slice tissue once it has become fixed ❖ Golgi silver stain - used when making detailed structural analysis of a small number of single cells which was named after Camillo Golgi ❖ Nissl stain - used when identifying clusters of cell bodies, the major bulk of the nerve cell within a sample tissue ❖ Myelin stain - allows to follow pathways carrying information from one part of the brain to another by staining the insulating material that covers many nerve fibers ❖ Horseradish peroxidase - used to discover the point of origin of the end of a pathway 2. Autopsy - examination of a body following death first method that was used because there was no technology to study the brain structures back then ❖ Simon LeVay - used autopsy to examine an area of the brain known as INAH-3 and believed that the size of it might be used to differentiate between homosexual and heterosexual ones 3. Imaging - provides significant advantage over autopsy can read the emotional responses of a person ❖ Wilhelm Rontgen- laid the groundwork for medical imaging and discovered X-rays in 1896 A. Computerized Tomography (CT) - was invented in 1972 by Godfrey Hounsfield and Allan Cormack - “tomography” came from the Greek words tomos which means ‘slice’, and graphia meaning ‘to write or describe’ - does not show anything about the brain activity but the mere structure of it B. Positron Emission Tomography (PET) - allowed researchers to observe the brain activity for the first time (red and yellow - high activity; green, blue, and black - low activity) - were made possible by the invention of gamma camera which used to detect radiation released by radioactive atoms that were decaying or breaking up - relies on and combine radioactive tracers with a wide variety of molecules including oxygen, water, and drugs - each gamma ray resulting from the breakdown of the tracer is recorded by detectors and fed to a computer by which the data are reconstructed into images C. Magnetic Resonance Imaging (MRI) - its first MRI image was produced by Raymond Damadian, Larry Minkoff, and Michael Goldsmith in 1977 - uses oxygen levels in the brain to determine the brain activity (the darker the area, the higher the oxygen levels and the more active the area is) ❖ Imaging technology - uses powerful magnets to align hydrogen atoms within a magnetic field ❖ Radio frequency (RF) pulses - directed at the part of the body to be imaged producing “resonance” or spinning of the hydrogen atoms ❖ Voxel - a three-dimensional version of a pixel in which each small area of tissue is assigned in order to construct an image ❖ Functional MRI - used to assess brain activity and takes advantage of the fact that active neurons require more oxygen than less active neurons and that variations in blood flow to a particular area will reflect this need (capable of determining and looking at the functions) - tracks cerebral blood flow through the different magnetic properties of hemoglobin (protein molecule that carries oxygen within the blood) when combined with oxygen or not - the use of this to track blood flow was previewed in the 19th century by William James who was impressed by the observations of Italian psychologist Angelo Mosso on patients with head injuries - Mosso was able to measure and correlate blood flow with the patients’ mental activity due to the nature of head injuries in which some of their skull bones were missing or damaged- - Roy Sherrington confirmed Mosso’s observations in 1890 and reported the existence of “an automatic mechanism by which the blood supply of any part of the cerebral tissue is varied in accordance with the activity of the chemical changes which underline the functional action of that part” 4. Recording A. Electroencephalogram (EEG) - first recordings of human brain’s electrical activity measured through electrodes placed on the scalp and cannot penetrate through the other areas of the brain - made by a German psychiatrist, Hans Berger in 1924 - measure the activity of large number of cells known as a field potential - several factors produce some distortion of the relationship between the actual activity of the brain and the recorded filed potentials - most highly influenced by the activity of cortical cells closest to the electrodes because the recording electrodes are located on the surface of the scalp ❖ Computerized EEG brain tomography - can be used to generate maps of activity, making it possible to pinpoint the source of abnormal activity ❖ EEG brain tomography - can be used to follow a patient through withdrawal from psychoactive drugs or during coma - can aid in diagnoses of many disorders including schizophrenia, dementia, epilepsy, and ADHD B. Evoked Potentials - an application of basic EEG technology and is mostly used in the assessment of the sensory activity (very helpful in ABPSYCH e.g., when a child has an autism, we can determine whether the child can actually hear through observations of evoked potentials to sound) - allows researchers to correlate the activity of the cortical sensory neurons recorded through scalp electrodes with stimuli presented to the participant C. Magnetoencephalography (MEG) - allows researcher to record the brain’s magnetic activity (Cohen, 1972) whereas active neurons put out tiny magnetic fields - measure magnetic activities deep within the brain (usually used alongside MRI) - advantage: recording magnetism rather than electrical activity relates to the interference of the skull bones and other tissues separating the brain from the electrodes - utilizes sensors known as superconducting quantum interference devices or SQUIDs that convert magnetic energy into electrical impulses that can be recorded and analyzed - aside from allowing researchers to localize cognitive functions such as language, it also provides precise localization of the source of the abnormal electrical activity that characterizes a seizure 5. Brain Stimulation - stimulate parts of the brain to know its function as it becomes more active problem: areas of the brain are densely closed to one another (i.e., dikit-dikit) causing it to stimulate other areas of the brain as well that we are not intended to stimulate relates to the localization of functions within the brain and nervous system ❖ Individual variations - occur in the patterns of localization of many cognitive functions such as language 6. Lesion - damaging the area of the brain - an injury to the neural tissue and can be either naturally occurring or deliberately produced - generally performed in a number of ways (e.g., large areas of brain tissue are surgically removed in some studies) and in research using laboratory nonhuman animals - occasionally used to treat cases of epilepsy that do not respond to medication - identified a role for the ventromedial hypothalamus (VMH) in satiety with the use of animals (classic example of lesion work) - experimentally produced when an electrode is surgically inserted into the area of interest - electrode is insulated except at the very tip to prevent damage to cells lining the entire pathway of the electrode; heat is generated at the tip of the electrode which effectively kills a small population of cells surrounding the tip ❖ Small lesions - can be produced by applying neurotoxins, chemicals that specifically kill neurons, into the area of interest through a surgically implanted micropipette ❖ Reversible lesion - can be produced by cooling an area using a probe ❖ Cooling - freezing the area of the brain then returning it to its normal function so as to not cause irreversible damage 6 MAJOR DIVISIONS OF BIOPSYCHOLOGY 1. Physiological Psychology - - division of biopsychology that studies the neural mechanisms behavior through direct manipulation and recording of the brain in controlled experiment—surgical and electrical methods are most common has a tradition of pure research that emphasizes on research that contributes to the development of theories of the neural control of behavior rather than on research of immediate practical benefit 2. Psychopharmacology - focuses on the manipulation of neural activity and behavior with drugs its substantial portion is applied to develop therapeutic drugs or to reduce drug abuse 3. Neuropsychology - - study of the physiological effects of brain in human patients uses quasi-experimental when using human subjects and uses nonhuman if the damage is to be inflicted by the neuropsychologists themselves ❖ Cerebral cortex - outer layer of the cerebral hemispheres that is most likely to be damaged by accident or surgery; this is one reason why neuropsychology has focused on this important part of the human brain most applied of the biopsychosocial subdisciplines ❖ Neuropsychological tests -facilitate diagnosis and help attending physician prescribe effective treatment; can also be an important basis for patient care and counseling (Kolb & Wishaw, 1990) 4. Psychophysiology - studies the relation between physiological activity and psychological processes in human subjects its recording procedures are typically noninvasive in that physiological activity is recorded from the surface of the body of human subjects ❖ Scalp electroencephalogram (EEG)- usual measure of brain activity; other measures include muscle tension, eye movement, and several indicators of autonomic nervous system activity (e.g., heart rate, blood pressure, pupil dilation, and electrical conductance of the skin) 5. Cognitive Neuroscience - youngest division of biopsychology ❖ Functional brain imaging - major method of cognitive neuroscience which refer to recording images of the activity of the living human brain while a participant is engaged in a particular cognitive activity 6. Comparative Psychology - deals generally with the biology of behavior rather than specifically with the neural mechanisms employ comparative analysis LESSON 2: BIOLOGICAL PSYCHOLOGY OF THE BRAIN THE CELLS OF THE NERVOUS SYSTEM ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ The nervous system consists of two kinds of cells, neurons and glia. Adult human brain contains approximately 86 billion neurons on average. The brain consists of individual cells. Charles Sherrington and Santiago Ramon y Cajal – scientists of the late 1800s who are widely recognized as the main founders of neuroscience Microscopy revealed few details about the nervous system during late 1800s not until Camillo Golgi, an Italian investigator, found a way to stain nerve cells with silver salts. Cajal used Golgi’s methods but applied them in infant brains, in which the cells are smaller and therefore, easier to examine on a single slide. His research demonstrated that nerve cells remain separate instead of merging into one another. Most chemicals cannot cross the membrane, but protein channels in the membrane permit a controlled flow of water, oxygen, sodium, potassium, calcium, chloride, and other important chemicals. All animal cells have a nucleus, the structure that contains the chromosomes, EXCEPT for mammalian red blood cells. Mitochondrion (plural: mitochondria) - performs metabolic activities, providing energy that the cell uses for all activities have genes separate from those in the nucleus of a cell differ from one another genetically Ribosomes - sites within a cell that synthesize new protein molecules some float freely within the cell but others are attached to the endoplasmic reticulum, which is a network of thin tubes that transport newly synthesized proteins to other locations Neurons - responsible for transmitting information from one neuron to another all include a soma (cell body), and most have dendrites, an axon, and presynaptic terminals tiniest lack axons and some lack well-defined dendrites TWO TYPES OF NEURONS 1. Motor Neuron - transmits messages for the movement (i.e., muscles) with its soma in the spinal cord, receives excitation through dendrites and conducts impulses along its axon to a muscle efferent 2. Sensory Neuron - transmits messages from the senses (i.e., vision, olfactory, gustation, etc.) specialized at one end to be highly sensitive to a particular type of stimulation such as light, sound, or touch conducts touch information from the skin to the spinal cord afferent Vertebrate Axons - covered with an insulating material called myelin sheath (a protective covering that protects the axon) with interruptions known as nodes of Ranvier (RAHN-vee-ay) Dendrites - comes from the word "tree" the one receiving information from the other neurons has wider range (mas malaki ‘yung sakop) in which the wider it becomes, the more information it is capable of admitting branching fibers that get narrower near their ends its surface is lined with specialized synaptic receptors at which the dendrite receives information from other neurons Cell Body or Soma (plural: somata) - - head of neurons contains the nucleus, ribosomes (synthesized cells, and mitochondria (it is the power house of the cell because it is where the energy production for the neurons occur; people could have overactive or less active mitochondria; people who have overactive one tends to fuel easily; those who have less active mitochondria are more susceptible/predisposed to depression) most of the metabolic activities occur here Axon - thin fiber of constant diameter comes from a Greek word meaning “axis” conveys impulse towards other neurons, muscle, and organ, or a muscle tail of neurons longer compared to dendrites (malawak lang ang dendrites) A. Afferent Axon (A - admit) - brings information into a structure - all sensory neurons are afferent to the nervous system B. Efferent Axon (E - exit) - carries information away from a structure - all motor neurons are efferent to the nervous system Glia or Neuroglia - has different functions depending on its type (e.g., astrocyte and oligodendrocytes) mas marami sa cerebral cortex removes weak synapsis (information na hindi na nagagamit) TYPES OF GLIA Astrocytes - star-shaped wrap around the synapses of functionality related to axons responsible for synchronization of neurons which is necessary for our behaviors that need to be synchronized dilate blood vessels so that more nutrients can enter the brain in the more active area - responds to the hormones it is the active partner of the neuron as it always works together with it Microglia - act as part of the immune system that removes viruses and fungi from the brain responsible for weakening the synapsis (space between the neuron) removes the dead neurons more effective against several other viruses that enter the brain, mounting an inflammatory response that fights the virus without killing the neuron (Ousman & Kubes, 2012) Oligodendrocytes - oligodendrocytes in the spinal cord but Schwann cells in periphery of the body build the myelin sheaths that surround and insulate certain vertebrate axons supply the axon with nutrients necessary for the neurons to function well Radial Glia - guide the migration of neurons and their axons and dendrites during the embryonic development most of it differentiate into neurons while a smaller number differentiate into astrocytes and oligodendrocytes when embryological development finishes guides the migration of neurons and their axons and dendrites during embryotic development Blood-brain Barrier - - mechanism that excludes most chemicals from vertebrate brain when a virus invades a cell, mechanisms within the cell extrude virus particles through the membrane so that the immune system can find them when the immune system cells discover a virus, they kill it and the cell that contains it for protection so that there will be no intruders that can enter and might damage our nervous system blocks some of the nutrients that we need in which there is a mechanism that they have to do first in order for them to enter oxygen, carbon dioxide, and all molecules that dissolve in fats can cross its walls easily and freely without such a mechanism because no special molecule is required for small, uncharged molecules most of the drugs used in chemotherapy do not really cross/enter the blood-brain barrier which is the reason why it is not 100% effective depends on endothelial cells that form walls of the capillaries—such cells are separated by small gaps outside the brain but are in the brain, joined together so tightly that they block viruses, bacteria, and other harmful chemicals from passage water crosses through special protein channels in the wall of the endothelial cells (AmiryMoghaddam & Ottersen, 2013) ❖ Active transport - protein-mediated process that expends energy to pump chemicals from the blood into the brain; used by the brain for certain chemicals such as glucose (main fuel of brain), amino acids (building blocks of proteins), purine, choline, a few vitamins, and iron) - - insulin and certain other hormones also cross blood-brain barrier in small amounts although the mechanism is not yet known Synapse - specialized gap between neurons (Charles Scott Sherrington, 1906) where the transfer of neurotransmitters or chemicals of our brain occur ❖ Charles Scott Sherrington - physiologically demonstrated that communication between one neuron and the next differs from communication along a single axon ❖ Ramon y Cajal - anatomically demonstrated a narrow gap separating one neuron from another in late 1800s ❖ If communication between neurons is special in some way, neurons are anatomically separate from one another. Presynaptic Terminal - also known as end bulb or bouton (French for “button) which refers to the swelling in the end of each branch of axon where the chemicals are being released junction or point where the chemicals are being released where the chemicals came from Presynaptic Terminal - receives the chemicals that will be bind in the receptors allowing the neurotransmitters to do its function storage of neurotransmitters ❖ Synthesis of smaller neurotransmitter such as acetylcholine. - neurotransmitters usually do not get to be released immediately once they were formed as it will first reside in the presynaptic terminal. we have to wait for calcium to enter into the cells before they are released ❖ Action potential causes calcium to enter, releasing neurotransmitter. - exocytosis will occur once the calcium enters inside the cells, which is the release/burst of neurotransmitters - calcium enters our cells because of our action potential (travels down towards the axon at kapag umabot na sa pinakadulo/terminal o bulb/endpoint, it would allow the calcium to enter the cells and as it enters the cells, the neurons will then release neurotransmitters) ❖ Neurotransmitter binds to the receptor. - as it binds with the receptor, neurotransmitters can now do their functions. - different situation happens depending on the function of the neurotransmitters: some will diffuse (goes to our feces na nililinis ni nitric oxide), some will reuptake (babalik sa pinanggalingan, sa presynaptic terminal, para magamit/marecycle ulit - the more na mas matagal na nakabind sa receptor, the more na mas matagal yung function o effect dun sa tao ❖ Nitric oxide - oddest transmitter because pag naform, marerelease na agad sya, hindi na nya inaantay ang calcium NEUROTRANSMITTERS Inactivation & Reuptake - e.g., acetylcholinesterase: acetate (reuptake), choline (diffuses) Negative Feedback (from the postsynaptic cells) - occurs when neurons release too much neurotransmitters A. Presynaptic Terminal - have receptors sensitive to same transmitter they release in which these receptors are called autoreceptors that respond to the released transmitter by inhibiting the further synthesis and release of the same chemicals B. Postsynaptic Neurons - respond to stimulation by releasing chemicals that travel back to the presynaptic terminal to inhibit further release of transmitter (e.g., nitric oxide) Electrical Synapses - synchronous in that it releases synapses at the same time occur when our body engages in movements that require synchronization Hormones - - one of its major differences with neurotransmitters is that most of the hormones have long-term effect once it took effect (e.g., growth hormone) while neurotransmitter has short-term effect in that the effect eventually loses its effect there are certain behaviors caused by hormones (e.g., stress hormones) the more fluctuated it is, the more possible that a mood disorder may develop/arise Nervous System - - composed of 1) central nervous system (CNS) which contains the brain and spinal cord and 2) peripheral nervous system (PNS) which connects the brain and spinal cord to the rest of the body PNS contain 1) somatic nervous system which consists of the axons conveying messages from sense organs to the CNS and from CNS to the muscles and 2) autonomic nervous system (ANS) which controls the heart, intestines, and other organs ANS consists of 1) sympathetic nervous system, a network of nerves that prepare the organs of vigorous activity and consists of chains in ganglia just to the left and right of spinal cord’s central regions (thoracic and lumbar areas) / fight or flight / releases norepinephrine; and 2) parasympathetic nervous system which is responsible for resting or calming / "para" so tigil / releases acetylcholine MAJOR DEVISIONS OF THE BRAIN Hindbrain - posterior part of the brain that consists of medulla, pons, and cerebellum 1. Medulla Oblongata - responsible for vital reflexes (e.g., coughing, sneezing) necessary for survival has many opiate receptors that suppress the activity of the medulla oblongata 2. Pons - Latin term for bridge (because it connects axons to the spinal cord) helps medulla oblongata in our vital reflexes most vital among the three because once it is damaged will lead to sudden death contain many nerves like cranial nerves vagus nerve is the longest cranial nerve 3. Cerebellum - large hindbrain structure with many deep folds first to become affected when a person is intoxicated with alcohol because it is responsible for balance and coordination damage with this causes problem with shifting of attention from auditory to visual stimuli and difficulty in timing/reaction time necessary for learning and conditioning in that the conditioned behavior happened because of it Forebrain - most prominent part of the mammalian brain which consists of two cerebral hemispheres 9one on left and one on right) 1. Thalamus - all the sensory information (except for olfaction) goes here first coming from the structure of our body before it goes to the cerebral cortex responsible for further processing them and then returning it back to the thalamus 2. Hypothalamus - responsible for our motivated behaviors feeding, fighting, fleeing, and sexual behavior the one communicating with the pituitary gland to release certain hormones 3. Basal Ganglia - its main function is movement responsible for habitual learning 4. Basal Forebrain - arousal, attention, and wakefulness (related with sleep and attention) 5. Hippocampus - responsible for memory - - people easily forgot things when they are depressed or stressed because prolonged stress result to too much cortisol damaging the hippocampus (lumiliit) thereby affecting its functioning or impairment in memory some people are born with small hippocampus which makes those people more susceptible to predisposal to certain disorders Cerebral Cortex - occipital (at the back), frontal (front), parietal (tuktok), and temporal (temples sa dalawang sides) has the same positions with all other species; the only difference is the convolutions (folding) wherein more convolutions/folding, the more intelligent an organism is 1. Occipital Lobe - - vision primary visual cortex responsible for visionary experience—if a personal only has a cortical blindness (the problem is in the cortex which affects the occipital lobe), they have normal eyes but they never experience dreams and any visual perception such that the cortex is the one that gives us visual experiences people who became blind because of certain damage in the eyes still have visual experience because there is no problem with their visual cortex the eyes provide the stimulus but the cortex provides the visual experiences as it interprets visual information occipital lobe is responsible for our dreams 2. Parietal Lobe - monitors information of the positions of our body (spatial information) and sends it to primary somatosensory cortex which is responsible for controlling and correct movement 3. Temporal Lobe - - responsible for understanding spoken language (Wernicke area); speech production (bronchus area) in relation to schizophrenia, the bronchus area is over active to people with this condition (auditory hallucinations) which imply that they are not really hearing something from the outside but from themselves responsible for emotions Kluver-Bucy Syndrome - nawawalan ng emotions 4. Frontal Lobe - human executive functioning (thinking, decision-making, personality, etc.) could cause major change in behavior and personality if damaged most of its anterior portion is the prefrontal cortex posterior portion is associated mostly with movement middle zone pertains to working memory (ability to remember your recent events without interrupting what you are doing), cognitive control, and emotional reactions anterior zone of the prefrontal cortex is most important for making decisions, evaluating which of several courses of action is likely to achieve the best outcome (affected when drinking alcohol)
