Biopsychology Reviewer PDF

BIOPSYCHOLOGY AS A NEUROSCIENCE (CHAPTER 1) Neuroscience is the study of the nervous system - from structure to function, development to degeneration, in health and in disease What is Biopsychology? - also called physiological psychology is the scientific study of the biology...

BIOPSYCHOLOGY AS A NEUROSCIENCE (CHAPTER 1) Neuroscience is the study of the nervous system - from structure to function, development to degeneration, in health and in disease What is Biopsychology? - also called physiological psychology is the scientific study of the biology of behavior. -denotes a biological approach to the study of psychology. Origin of Biopsychology Pre-Biological Explanations - In the past, behavior had been explained as a product of supernatural or natural elements Origin of Biopsychology Psychological Tradition - Insanity was a natural phenomenon, caused by mental or emotional stress - Nicholas Oresme, argued that depression was a result of "bizarre behaviors" Origin of Biopsychology Biological Tradition - Hippocrates, Father of Western Medicine, explained that hysteria is caused by the uterus - Galen adopted the ideas of Hippocrates creating the humoral theory of disorders. Origin of Biopsychology Biological Tradition - Sigmund Freud, behavior is determined by sexual and aggressive drives - Erik Erikson - development follows the epigenetic principle according to a predetermined rate Origin of Biopsychology Hans Eysenck's Biologically Based Factor Theory - Personality has three dimensions: Extaversion, Neuroticism, Psychoticism. They are largely inherited rather than learned Extraversion - cortical arousal and sensory thresholds Neuroticism - diathesis-stress model Psychoticism - predisposition to stress that develops into psychological illness Origin of Biopsychology David Buss' Evolutionary Theory of Personality - Personality is shaped by evolutionary experiences in adaptation problems (survival & reproduction) and their mechanisms (solutions) Physical Mechanisms - physiological organs and systems that evolved to solve problems of survival Physiological Mechanisms - internal and specific cognitive, motivational, and personality systems that solve adaptation problems (Attraction - dominance, Trust - dependability, Intimacy - love) Origin of Biopsychology - It did not become a major neuroscientific discipline until the 20th century - The Organization of Behavior (1949) by Donald O. Hebb - learning based on conjunctures on neural networks and synapses being able to strengthen or weaken over time 3 Major Dimensions of Psychological Research 1. Human or non-human subjects 2. Formal experiments or non-experimental studies 3. Pure or applied 1.1 Human Subjects Advantages * They can follow instructions * They can report their subjective experiences * Humans are often cheaper 1.2 Non-Human Subjects Non-Human Subjects Advantages * The brains and behavior of non-human subjects are simpler than those of human subjects. Comparative approach * the study of biological processes by comparing different species. * Fewer ethical constraints on the study of laboratory species than on the study of humans. 2.1 Experiments -Is the method used by scientists to study causation - to find out what causes what. Independent Variable - the variable that is controlled by the experimenter by administering treatments. Dependent Variable -These variables are expected to change as a result of an experimental manipulation of the independent variable. Confounding Variable - is an outside influence that changes the effect of a dependent and independent variable. - This extraneous influence is used to influence the outcome of an experimental design. - is an extra variable entered into the equation that was not accounted for. Conditions -Designed by the experimenter under which the subjects will be tested. WITHIN-SUBJECTS DESIGN -all participants are exposed to every treatment or condition. Carryover Effect - is a type of practice effect that occurs because the results from one test influences another. (Whenever subjects perform in more than one condition as they do in within-subject designs) there is a possibility of carryover effects. BETWEEN-SUBJECTS DESIGN > A different group of subjects is tested under each condition. > The basic idea behind this type of study is that participants can be part of the treatment group or the control group, but cannot be part of both. > A between subjects design is a way of avoiding the carryover effects that can plague within subjects design. A. Quasi-experimental Studies - studies of groups of subjects who have been exposed to the conditions of interest in the real world. - These studies have the appearance of experiments, but they are not true experiments because potential confounded variables have no been controlled or randomly selected. B. Case Study - Studies that focus on a single case or subjects. - Provide a more in-depth picture that that provided by an experiment or quasi-experimental study. Disadvantage of Case Study > Generalizability - the degree to which the result can be applied to other cases. 3.1 Pure Research -Is research motivated primarily by the curiosity of the researcher. - It is done solely for the purpose of acquiring knowledge. 3.2 Applied Research -Is research intended to bring about some direct benefit to humankind. Six Major Divisions of Biopsychology A. Physiological Psychology B. Psychopharmacology C. Neuropsychology D. Psychophysiology E. Cognitive Neuroscience F. Comparative Psychology A. Physiological Psychology -Study of the neural mechanisms of behavior by manipulating the nervous systems of non-human subjects in controlled experiments. B. Psychopharmacology -Study of the effects of drugs on the brain and behavior. -The goal is develop therapeutic drugs or reduce drug abuse C. Neuropsychology -Study of psychological effects of brain damage in human patients. D. Psychophysiology -Study of the relation between physiological activity and psychological processes in human subjects by noninvasive physiological recording. E. Cognitive Neuroscience -study of the neural mechanisms of human cognition, largely through the use of functional brain imaging. Types of Brain Imaging 1. Functional Magnetic Resonance Imaging (fMRI) - can be used to produce activation maps showing which parts of the brain are involved in a particular mental process. 2. Computed Tomography (CT) Scan - builds up a picture of the brain based on the differential absorption of X-rays. 3. Positron Emission Tomography (PET) - uses trace amounts of short-lived radioactive material to map functional processes in the brain. 4. Electroencephalography (EEG) - is the measurement of the electrical activity of the brain by recording from electrodes placed on the scalp F. Comparative Psychology - study of the evolution, genetics, and adaptiveness of behavior, largely through the use of the comparative method. Chapter 2 EVOLUTION, GENETICS, AND EXPERIENCE There is a tendency in the scientific field to think about behavior in terms of dichotomies is illustrated by two kinds of questions: (1) Is it physiological, or is it psychological? 2) Is it inherited, or is it learned? PHYSIOLOGICAL OR PSYCHOLOGICAL (Original meaning of terms such as psyche) The dichotomy rose to prominence in the Western world after the Medieval Ages Much of the scientific knowledge that accumulated during the Renaissance was at odds with Church dictates. However, the conflict was resolved by the prominent French philosopher René Descartes René Descartes argued that physical matter (the brain) could be observed scientifically, but that the mind (soul) has no physical substance and is thus under the scope of religion Cartesian dualism was sanctioned by the church and and so, the idea that the human brain and the mind are separate entities became even more accepte THE PROBLEM WITH DICHOTOMIES There are two lines of evidence against physiological-or-psychological thinking: 1. Complex psychological changes can be produced by damage to, or stimulation of parts of the brain * The Case of the Man Who Fell Out of Bed THE CASE OF THE MAN WHO FELL OUT OF BED The patient felt fine when he woke, until he touched the thing in bed next to him. It was a severed human leg, all hairy and still warm! At first, the patient was confused. Then, he figured it out. One of the nurses must have taken it from the autopsy department and put it in his bed as a joke. Some joke; it was disgusting. So, he threw the leg out of the bed, but somehow, he landed on the floor with it attached to him. The patient became agitated and desperate, and Dr. Sacks tried to comfort him and help him back into the bed. Making one last effort to reduce the patient's confusion, Sacks asked him where his left leg was, if the one attached to him wasn't it. Turning pale and looking like he was about to pass out, the patient replied that he had no idea where his own leg was it had disappeared. (ASOMATOGNOSIA- awareness part of the body, which cannot detect a part of the body) 2. Some nonhuman species, particularly primate species, possess abilities that were once assumed to be purely human, such as self-awareness INHERITED OR LEARNED? For centuries, scholars have debated whether humans and other animals inherit their behavioral capacities or acquire them through learning. Commonly referred to as the nature-nurture issue The majority of early North American psychologists were committed to the nurture side of the issue John B. Watson, father of behaviorism “Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select doctor, lawyer, artist, merchant-chief and, yes even beggar-man and thief.” INHERITED OR LEARNED? Coinciding with North Americas experimental psychology was European ethology, which focused on instinctive behaviors THE PROBLEM WITH DICHOTOMIES It was changed after it was argued that behaviour always develops under the combined control of both nature and nurture o It is better to think of it as genetics and experience interacting rather than a dichotomy BEHAVIORAL DEVELOPMENT Ontogeny: Development of individuals over their life span Phylogeny: Evolutionary development of species through the ages EVOLUTION Modern biology began in 1859 with the publication of Charles Darwin's On the Origin of Species where he described his theory of evolution THREE OF DARWIN'S SUPPORTING EVIDENCE 1. He documented the evolution of fossil records through recent geological layers 2. He described striking structural similarities among living species, which suggested that they had evolved from common ancestors 3. He pointed to the major changes that had been brought about in domestic plants and animals by programs of selective breeding EVOLUTION Evolution occurs through natural selection: heritable traits that are associated with high rates of survival and reproduction are the most likely ones to be passed on to future generations Repeated cycles of this process lead to evolution of the species that are better adapted to surviving and reproducing in their particular environmental niche MECHANISMS OF BEHAVIOR Social Dominance: Males of a species often establish a hierarchy of social dominance, sometimes through combat. The dominant male usually copulates more than lower-ranked males. Courtship Display: The male usually signals to the female to elicit a response, though copulation may fail if one of the pair fails to re appropriately to the signal BEHAVIORAL DEVELOPMENT Robert Tryon theorized that behavioral traits can be selectively bred He experimented with rats by teaching them how to run a maze He mated the males and females that entered incorrect alleys least frequently (maze-bright) and he mated the males and females that entered incorrect alleys most frequently (maze-dull) By the 8th generation, the worst of the maze-bright strain made fewer errors than the best of the maze-dull strain GENETICS OF HUMAN PSYCHOLOGICAL DIFFERENCES All human traits are highly heritable Being raised in different family environments contributes little to the diversity of behavioral traits. A Minnesota study of twins had results that showed that even if monozygotic twins were raised in different family environments, they were substantially more like one another than fraternal twins BEHAVIORAL DEVELOPMENT Phenylketonuria (PKU): Neurological disorder born from a genetic mutation. Low levels in the amino acid phenylalanine can lead to intellectual disability if untreated. Was discovered by the Norwegian dentist Ivar Asbjorn Folling when he noticed that the urine of his mentally retarded children had a peculiar odor (samples of their urine showed high levels of phenylpyruvic acid) ANATOMY OF THE NERVOUS SYSTEM STANDARD ANATOMICAL POSITION It refers to the specific body orientation used when describing an individual's anatomy. It consists of the body standing upright and facing forward with the legs parallel to one another. The upper limbs, or arms, hang at either side and the palms face forward. PLANES OF THE BODY These are imaginary reference points that divide the body into various sections in order to help describe relative anatomy. SAGITTAL PLANE- DIVIDES THE BODY INTO RIGHT AND LEFT PARTS. CORONAL PLANE- DIVIDES THE BODY INTO ANTERIOR AND POSTERIOR PARTS. TRANSVERSE PLANE- DIVIDES THE BODY INTO SUPERIOR AND INFERIOR PARTS. NERVOUS SYSTEM Coordinates all activities of the body Enables the body to responds and adapts to changes CELLS OF THE NERVOUS SYSTEM ANATOMY OF NEURONS NEURONS Are cells that are specialized for the reception, conduction, and transmission of electrochemical signals. EXTERNAL ANATOMY OF NEURONS NUCLEUS - contains the cell's genetic material CELL BODY - also called the soma, provides energy, maintains structure, and contains genetic information. DENDRITE - are projections from the cell body. The main function of dendrites is to receive information from other neurons, AXON - long, thin nerve fiber that transmits electrical impulses away from a neuron's cell body MYELIN SHEATH - a fatty layer that surrounds and Insulates nerve cells, NODE OF RANVIER - are gaps in the myelin sheath that regenerate action potentials along axons, allowing for faster and more efficient communication. action potential is a rapid change in the voltage across a cell membrane AXONTERMINAL - the ends of axons which transmit messages to other cells via use of neurotransmitters at synapses Classes of Neurons UNIPOLAR NEURON A neuron with one process extending from its cell body. Only occurs in invertebrate glands and muscles. PSEUDO-UNIPOLAR NEURON The nerve process extending from the cell body splits into two branches or axons. Sensory neurons BIPOLAR NEURON has two distinct structures extending from the cell body. One is an axon, and the other is a dendrite. olfactory epithelium, retina, and certain nerves within the ear MULTIPOLAR NEURON A neuron with more than two process extending from its cell body Are present throughout a person's CNS, including the brain and associated nerves in the autonomic nervous system GLIAL CELLS Found throughout the nervous system The glial cells surround neurons and provide support for and insulation between them. Glial cells are the most abundant cell types in the central nervous system. TYPES OF GLIAL CELL Oligodendrocytes - their main functions are to provide support and insulation to axons in the central nervous system. Schwann cells - any of the cells in the peripheral nervous system that produce the myelin sheath around neuronal axons. They guide axonal regeneration (regrowth) after damage GENERAL LAYOUT OF THE NERVOUS SYSTEM CENTRAL NERVOUS SYSTEM (CNS) Division of the nervous system that is located within the skull and spine the integrating and control center of the nervous system 1. BRAIN Part of the CNS that is located in the skull Controls all major body function the organ inside the head that controls thought, memory, feelings, and activity FIVE MAJOR DIVISIONS OF THE BRAIN HINDBRAIN a region of the brain that controls many vital functions, including breathing, heartbeat, and motor coordination MYELENCEPHALON (MEDULLA) The most posterior division of the brain is composed largely of tracts carrying signals between the rest of the brain and the body. Medulla Oblongata helps control vital processes like your heartbeat, breathing and blood pressure. METENCEPHALON Part of the hindbrain that differentiates into the pons and the cerebellum PONS -. It is involved in the control of breathing, communication between different parts of the brain, and sensations such as hearing, taste, and balance. CEREBELLUM - receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements. MIDBRAIN a small but important part of the brain that connects the forebrain and hindbrain MESENCEPHALON (MIDBRAIN) Is a portion of the central nervous system associated with vision, hearing, motor control, sleep/wake, arousal and temperature regulation. TWO DIVISIONS OF MESENCEPHALON TECTUM -dorsal (top) part of the midbrain. * -INFERIOR COLLICULI - is involved in auditory processing. * -SUPERIOR COLLICULI - is involved in visual function and control of eye movements. TEGMENTUM - is the division of the mesencephalon ventral (lower) to the tectum. It promotes cardiorespiratory functions and airway-protective reflexes FOREBRAIN controls body temperature, reproductive functions, eating, sleeping, and the display of emotions. DIENCEPHALON is situated between the telencephalon and the midbrain. Composed of two structures: THALAMUS AND HYPOTHALAMUS THALAMUS Is a large mass of grey matter in the dorsal part of the diencephalon of the brain. relays motor and sensory signals to the cerebral cortex. It also regulates sleep, alertness, and wakefulness HYPOTHALAMUS It exerts its effects in part by regulating the release of hormones from the pituitary gland which dangles from it on the ventral surface of the brain. It plays an important role in the regulation of several motivated behaviors (e.g., eating, sleep, and sexual behavior) TELENCEPHALON (CEREBRUM) The largest division of the human brain. responsible for the integration of complex sensory and neural functions and the initiation and coordination of voluntary activity in the body. FRONTAL LOBE The frontal lobes make up the largest part of the cortex. - Their central functions are to process information relating to memory, planning, decision making, goal setting, and creativity. -The frontal lobes also contain the primary motor cortex that regulates muscular movements. TEMPORAL LOBE located on the side of the cerebrum, is responsible for processing auditory information. PARIETAL LOBE - Located at the top of the brain in the cerebrum are responsible for the sense of touch, and they help to determine body position and integrate visual information. -The parietal lobes have anterior (front) and posterior (rear) sections. OCCIPITAL LOBE are primarily concerned with processing visual information. The occipital lobe also is known as the visual cortex. CEREBRAL CORTEX The outermost layer of the brain contains gray matter. Responsible for many higher order functions like language and information processing. LIMBIC SYSTEM Is involved in the regulation of motivated and emotional behaviors process your memory, thoughts and motivations, then tell your body how to respond. AMYGDALA is involved in the control of emotion, survival instincts and memory. The amygdala's function is to assess the harmfulness of sensory inputs. HIPPOCAMPUS is the brain structure responsible for memory of the immediate past. FORNIX - is a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus. - Damage to the fornix has been associated with anterograde amnesia-inability to create new memories. CINGULATE CORTEX It is involved in processing emotions and behavior regulation. It also helps to regulate autonomic motor function. BASAL GANGLIA responsible primarily for motor control, as well as other roles such as motor learning, executive functions and behaviors, and emotions. CAUDATE NUCLEUS Means "tail-like” The caudate nucleus is a C-shaped structure. It's responsible for processing visual information, movement, and memory. PUTAMEN the outer part of the nucleus of the brain. is involved in motor learning, speech articulation, language functions, reward, cognitive functioning, and addiction STRIATUM decision making functions, such as motor control, emotion, habit formation, and reward. GLOBUS PALLIDUS control conscious and proprioceptive movements. (your body's ability to sense movement, action, and location) 2. SPINAL CORD Is a long, thin bundle of nervous tissue and support cells connected to the brain and located along your back and neck Receives and transmits electrical signals throughout the entire body and then back to the brain The spinal cord is protected by the vertebrae, which are bones running down your back, and also by cerebral spinal fluid, which help to cushion the nerve tissue TWO DIFFERENT AREAS OF SPINAL CORD GRAY MATTER WHITE MATTER GRAY MATTER is a tissue in the brain and spinal cord that processes and interprets information. It plays a significant role in mental functions, memory, emotions and movement. is composed largely of unmyelinated axons. 3 LAYERS OF MENINGES Are layers of tough and connective tissue that protect and cover the brain and spinal cord MENINGES, VENTRICLES, AND CEREBROSPINAL FLUID 3 LAYERS OF MENINGES A.DURA MATER - the thickest and outermost of the three meninges surrounding the brain and spinal cord. B. ARACHNOID MATER - Spider weblike membrane - the middle of the three membranes covering the brain and spinal cord. It is separated from the pia mater by the “subarachnoid cavity" which is filled with "cerebrospinal fluid." C.PIA MATER - is the meningeal envelope that firmly adheres to the surface of the brain and spinal cord. It is a very thin membrane composed of fibrous tissue covered on its outer surface by a sheet of flat cells CEREBRAL VENTRICLES Are the four large internal chambers of the brain; the two lateral ventricles, the third ventricle, and the fourth ventricle are responsible for the production, transport and removal of cerebrospinal fluid, CENTRAL CANAL also known as ependymal canal, is the cerebrospinal fluid-filled space that runs longitudinally through the length of the entire spinal cord. The central canal is continuous with the ventricular system of the brain. CEREBROSPINAL FLUID (CSF) is a clear, colorless body fluid found in the brain and spinal cord. Fills the subarachnoid space, the central canal of the spinal cord, and the cerebral ventricles of the brain BLOOD-BRAIN BARRIER Composed of tightly packed cells of the brain's blood vessel walls Impedes the passage of many toxic substances from the blood into the brain B. PERIPHERAL NERVOUS SYSTEM (PNS) is the division of the nervous system containing all the nerves that lie outside of the central nervous system (CNS). The primary role of the PNS is to connect the CNS to the organs, limbs, and skin. TWO DIVISIONS OF PNS Somatic Nervous System (SNS) Autonomic Nervous System (ANS) 1. SOMATIC NERVOUS SYSTEM (SNS) "VOLUNTARY" The somatic nervous system derives its name from the Greek word soma, which means "body." Is the part of the PNS that responsible for carrying sensory and motor information to and from the central nervous system. It is composed of afferent and efferent nerves A. AFFERENT NERVES Also known as sensory neurons Carry sensory signals from the skin, skeletal muscles, joints, eyes, ears, and so on, to the central nervous system B. EFFERENT NERVES Also known as motor neurons Carry motor signals from the central nervous system to the skeletal muscles. 2. AUTONOMIC NERVOUS SYSTEM (ANS) "INVOLUNTARY" is the part of the peripheral nervous system that regulates the body's internal environment. It is composed of afferent nerves that carry sensory signals from internal organs to the CNS and efferent nerves that carry motor signals from the CNS to internal organs. TWO KINDS OF EFFERENT NERVES UNDER ANS A.Sympathetic Nervous System (makes you alert) B. Parasympathetic Nervous System (makes you calm) A. SYMPATHETIC NERVOUS SYSTEM Are those autonomic motor nerves that project from the CNS in the lumbar (small of the back) and thoracic (chest area) regions of the spinal cord Regulates the flight or fight responses. B. PARASYMPATHETIC NERVOUS SYSTEM Are those autonomic motor nerves that project from the brain and sacral (lower back) region of the spinal cord Regulates the rest or digest response FUNCTIONS OF SYMPATHETIC AND PARASYMPATHETIC SYSTEMS SYMPATHETIC SYSTEM * Stimulate, organize, and mobilize energy resources in threatening situations * Sympathetic changes are indicative indicative of psychological of arousal PARASYMPATHETIC SYSTEMS * Act to conserve energy * Indicative of psychological relaxation Neural Conduction and Synaptic Transmission How Neurons Send and Receive Signals This chapter introduces you to their function how neurons conduct and transmit electrochemical signals through your nervous system * how signals are generated in resting neurons; * The signals are conducted through neurons and transmitted across synapses to other neurons. * how drugs are used to study the relation between synaptic transmission and behavior The Lizard, a Case of Parkinson s Disease Thave become a lizard, he began. A great lizard frozen in a dark, cold, strange world. His name was Roberto Garcia d Orta. He was a tall thin man in his sixties, but most like patients with parkinson's disease he appeared to be much older than his actual age. Not many years before, he had been an active, vigorous businessman. Then it happened not all at once, not suddenly, but slowly, subtly, insidiously. Now he turned like a piece of granite, walked in slow shuffling steps, and spoke in a monotonous whisper. What had been his first symptom? A tremor. Had his tremor been disabling? No, he said. My hands shake worse when they are doing nothing at all a symptom called tremor-at-rest. The other symptoms of Parkinson s disease are not quite so benign. They can change a vigorous man into a lizard. These include rigid muscles, a marked poverty of spontaneous movements, difficulty in starting to move, and slowness in executing voluntary movements once they have been initiated. The term reptilian stare is often used to describe the characteristic lack of blinking and the widely opened eyes gazing out of a motionless face, a set of features that seems more reptilian than human. Truly a lizard in the eyes of the world What was happening in Mr. d Orta s brain? A small group of nerve cells called the substantia nigra (black substance) were unaccountably dying. These neurons make a particular chemical called dopamine, which they deliver to another part of the brain, known as the striatum. As the cells of the substantia nigra die, the amount of dopamine they can deliver goes down. The striatum helps control movement, and to do that normally, it needs dopamine. RESTING MEMBRANE POTENTIAL Recording the Membrane Potential Position the tip of one electrode inside the neuron and the tip of another electrode outside the neuron in the extracellular fluid. The intracellular electrodes are called microelectrodes; their tips are less than one-thousandth of a millimeter in diameter. When both electrode tips are in the extracellular fluid, the voltage difference between them is zero. When the tip of the intracellular electrode is inserted into a neuron, a steady potential of about 70 millivolts (mV) is recorded In its resting state, with the 70 mV charge built up across its membrane, a neuron is said to be polarized. The membrane potential is the difference in electrical charge between the inside and the outside of a cell. Resting Membrane Potential Neurons have a selectively permeable membrane During resting conditions membrane is; Permeable to Potassium (K+) (channels are open) Impermeable to Sodium (Na+) (channels are closed) lonic Basis of the Resting Potential RII The resting potential is -70 millivolts The resting potential exist because positively and negatively charged ions are distributed unequally on the two sides of the neural membrane: the concentration of Na+ and CI-are higher outside the neuron, and the concentration of the K+ and various negatively charged proteins are higher inside the neuron Resting Membrane Potential Diffusion force pushes K+ out (concentration gradient) This creates a positively charged extracellular space Electrostatic force pushes K+ in Thus, there is a dynamic equilibrium with zero net movements of ions The resting membrane potential is negative Two (2) factors that act to distribute ions equally throughout the intracellular and extracellular fluids of the nervous system RANDOM MOTION: The ions in neural tissue are in constant random motion, and particles in random motion tend to become evenly distributed because they are more likely to move from areas of high concentration to areas of low concentration than vice versa. ELECTROSTATIC PRESSURE: Any accumulation of charges, positive or negative, in one area tends to be dispersed by the repulsion among the like charges in the vicinity and the attraction of opposite charges concentrated elsewhere. Four kinds of ions that contribute significantly to the resting potential: * sodium ions (Na*), * potassium ions (K*), * chloride ions (CI+), * Negatively charged protein ions. Synaptic Transmission: Chemical Transmission of Signals among Neurons Synapses: The places where neurons connect and communicate with each other Neurotransmitters: Neurotransmitter molecules are endogenous chemicals that allow neurons to communicate with each other throughout the body Release of Neurotransmitter Molecules EXOCYTOSIS: is the process of neurotransmitter release. When a neuron is at rest, synaptic vesicles that contain small-molecule neurotransmitters tend to congregate near sections of the presynaptic membrane that are particularly rich in voltage-activated calcium channels Reuptake, Enzymatic Degradation, and Recycling Reuptake is the process in which the majority of neurotransmitters, once released, are almost immediately drawn back into the presynaptic buttons by transporter mechanisms. Other neurotransmitters are degraded (broken apart) in the synapse by the action of enzyme proteins that stimulate or inhibit biochemical reactions without being affected by them. Glial Function and Synaptic Transmission Astrocytes have been shown to release chemical transmitters, to contain receptors for neurotransmitters, to conduct signals, and to participate in neurotransmitter reuptake Gap junctions are narrow spaces between adjacent neurons that are bridged by fine tubular channels, called connexins, that contain cytoplasm Neurotransmitters Chemical messengers that allow signals to cross synapses to transmit information from a nerve cell or neutron to a target cell Coordinate behavior by stimulating an action or inhibiting an impulse Amino Acid Neurotransmitters GLUTAMATE - excitatory neurotransmitter important to memory, cognition, and mood regulation. High levels = Parkinson's Alzheimer's; Low Levels = learning and memory issues GAMMA-AMINOBUTYRIC ACID (GABA) - slows down your brain by blocking specific signals in your central nervous system. Low levels = mood disorders, anxiety, schizophrenia, autism Monoamine Neurotransmitters They are subdivided into two groups, catecholamines and indolamines DOPAMINE - plays a role as a "reward center" and in many body functions, including memory, movement, motivation, mood, attention and more. EPINEPHRINE - also known as adrenaline, plays an important role in your body's "fight-or-flight" response. NOREPINEPHRINE - increases alertness, arousal and attention and affects your sleep-wake cycle, mood and memory SEROTONIN - regulates your mood. It's often called your body's natural "feel good" chemical. When serotonin is at normal levels, you feel more focused, emotionally stable, happier and calmer. Acetylcholine It is created by adding an acetyl group to a choline molecule. Acetylcholine is the neurotransmitter at neuromuscular junctions, at many of the synapses in the autonomic nervous system, and at synapses in several parts of the central nervous system. Acetylcholine is a neurotransmitter that plays a role in memory, learning, attention, arousal and involuntary muscle movement. Medical conditions associated with low acetylcholine levels include Alzheimer's disease and myasthenia gravis. Unconventional Neurotransmitters These neurotransmitters are produced in the neural cytoplasm and immediately diffuse through the cell membrane into the extracellular fluid and then into nearby cells SOLUBLE GAS- includes nitric acid and carbon monoxide. ENDOCANNABINOIDS- synthesized from fatty compounds in the cell membrane; they tend to be released from the dendrites and cell body, an anandamide Neuropeptides: are small proteinaceous substances produced and released by neurons through the regulated secretory route and acting on neural substances. Pituitary peptides contains neuropeptides that were first identified as hormones released by the pituitary; a Hypothalamic peptides contains neuropeptides that were first identified as hormones released by the hypothalamus; Brain gut peptides contains neuropeptides that were first discovered in the gut. Opioid peptides contains neuropeptides that are similar in structure to the active ingredients of opium, Miscellaneous peptides is a catch-all category that contains all of the neuropeptide transmitters that do not fit into one of the mother four categories.