Unit 1 Lecture Notes.docx

**Biological Psychology**: Kalat Intro: The Major Issues **Biological Psychology:** Study relationships between physiology and behavior Neuroscientist: neuroanatomy, neurophysiology Behavioral neuroscientist: behaviors affected by anatomy & physiology Cognitive neuroscientist: thought processes...

**Biological Psychology**: Kalat Intro: The Major Issues **Biological Psychology:** Study relationships between physiology and behavior Neuroscientist: neuroanatomy, neurophysiology Behavioral neuroscientist: behaviors affected by anatomy & physiology Cognitive neuroscientist: thought processes affected by physical substrates **Approaches in Biopsychology** Physiological: body processes EtOH binds to GABA~A~ receptor Ontogenetic: developmental Genetic predisposition? Early exposure? Evolutionary: aids survival, reproduction Intoxication as anxiolytic process? Functional: Why? What does it do? Anxiolytic, increases likelihood of mating? **Brain & Conscious Experience** Cartesian Dualism: mind and body (Body is physical; mind is not) Monism: a single entity Materialism: only the physical Mentalism: only the mind really exists Identity position: mental activity arises from processes in the brain, but described differently Theory of Mind: understanding that others exist as separate entities and can share common experience with our world **Medical Fields (MD)** Neurologist: treats nervous system Neurosurgeon: performs surgery on nervous system Psychiatrist: treats psychological disorders, can prescribe drugs **Academic Subfields (PhD)** Psychopharmacology: Drugs Psychoneuroendocrinology: Hormones Psychoneuroimmunology: Immune Health Psychology: Clinical area, health, stress Neuropsychology: Clinical area, assessment of brain damage in humans Psychophysiology: physiological recordings in humans (ANS) Physiological Psychologist: recordings in animals Comparative Psychologist: compares behavior across species (ethology) Sociobiologist: relies on evolutionary explanations for social development **Animal Research** NIH Guidelines for Care and Use of Animals: Reduce, Replace, Refine IUCAC oversee ethical use of research animals Most animals used in research are rodents Costly Animals provide systems we can study; Sometimes the animal is studied to advance techniques for the species **Simple to Complex** Mammals share aspects of physiology and behavior Simpler systems can be manipulated; More generations to study **Comparisons Across Species: Several Figures comparing neocortex, etc** **Genetics & Evolution CH 4** **Darwin & Mendel** Darwin published on Evolutionary Theory. Mendel recorded observations on inherited characteristics. A common element was genetic transmission; Neither man was aware of genes Darwin never read the manuscripts Mendel wrote **\ ** **Genetics** Eukaryotic cells have a nucleus. Nucleus contains Chromosomes. Chromosomes contain DNA DNA contains genes. Genes code for proteins. Strings of amino acids \> peptides \> proteins Proteins are essential: Structural, enzymes, receptors, neuropeptides **Figure: Structure of Genetic Material** **Terms in Genetics** Genotype: the alleles or forms of the genes Dominant: Expressed T Recessive: Can be hidden t Many genes are not completely dominant Phenotype: the physical or psychological characteristic we can observe; eg, Tt & TT both supertasters **Genetic Transmission** Heterozygous: 2 different alleles: Tt Homozygous: the same allele: tt or TT Predictable outcome of Tt x Tt: One tt, One TT, Two Tt Probability 2:4 children Tt but 1:4 nontaster Not absolute **Twins** Monozygotic: Identical Dizygotic: Fraternal **Heritability** Twin studies are used to determine heritability Correlation expected to be higher between MZ than DZ to support role of genetics Each study is a snapshot; heritability applies to the sample studied **Sources of Variation** Recombination: genes combine to yield characteristics not found in either parent Mutation: a random change in a single gene Contiguous genes are usually inherited together e.g., BC or bc Crossing over: pair of chromosomes exchange parts BC and bc become Bc and bC **Epigenetics Figure Epigenetic Process** Changes in gene expression without the modification of the DNA sequence Some genes are active only at a certain point in one's life, a certain time of day, etc. Changes in gene expression are central to learning and memory Epigenetic differences likely explain differences between monozygotic "identical" twins **Sex Chromosomes** Sex-linked genes on X & Y chromosomes Male (XY) expresses X-linked recessive genes Female (XX) both must be recessive Sex-limited genes: Effect is limited or almost limited to one sex eg, chest hair, breast size Genes expressed only after activation by sex hormones **Heredity & Environment Figure on Reaction Range** Reaction range: born with a range of an ability wherein the environment pushes you up or down. Prenatal influences can affect which genes get turned on Methylation inactivates genes in some cases of malnutrition, stress, drug use Multiplier effect: early tendency can change environment to magnify effect Epigenetics **\ ** **Evolution** Change over generations in the frequency of certain genes in a population Not necessarily progress; some changes are harmful Mutations or recombinations produce unique genetic elements Natural selection in terms of features that aid in SURVIVAL and REPRODUCTION **Misconceptions About Evolution** Use or disuse affects evolution? No. Actually, that's Lamarckian. Reproduction is key. Have humans stopped evolving? No. Not just survival of fittest, but Reproduction Does evolution mean improvement? Maybe. Environment can change so adaptation no longer advantage Survival of individual or species? Neither. Survival of the gene **Neuroconduction: Nerve Cells and Nerve Impulses Kalat Ch 1** **Microscopy** Advances in microscopy and staining was important for understanding the cells of the nervous system. Ramon y Cajal was a pioneer. Used Golgi's silver stain on infant cells Demonstrated independent cells, not 'nets' **Cell Constituents Neuronal Structures Figure** Membrane: separates cell from environment Nucleus: contains the chromosomes (DNA) Mitochondrion: performs metabolic activities Ribosomes: synthesizes new proteins Endoplasmic reticulum: transport newly synthesized proteins to other locations **Types of Cells in Nervous System** Neurons: Receive and transmit information to other cells Functional unit of NS Glia: Structural, ion balance, nutrients & waste Glia are10 x in number but 1/10 in size About 100 billion neurons and glial cells **Anatomy of a Neuron** Dendrites: receive information (see Figure) Dendritic spines: short outgrowths; ↑surface area available for synapses Soma: cell body, contains organelles Axon: send to the pre-synaptic terminals One axon per neuron; hard to find in interneurons **Special Structures of Neuron See Figure of Motor Neuron** Myelin sheath: insulation on axons that speeds up action potential Axon hillock: juncture of soma and axon; High density of Na^+^ channels Presynaptic terminal: the end point on the axon that releases chemicals **Types of Neurons See Figure** Motor neuron: movement Interneuron: processing Sensory neuron: detects environment **Efferent (Motor) Neuron See Figure** Produce movement, contraction Efferent axon carries information away from NS: motor neurons **Interneuron See Figure** Interneuron = relay neuron or intrinsic neuron: processing Axon hard to find to nonexistent; Use graded potentials Local, contained within a single neural structure **Sensory Neuron See Figure** Detects external world Afferent axon brings information into NS: sensory neurons Sensitive to a particular type of stimulation **Properties of Neurons** Size: micro to meter in length Shape: varies (Stellate, Pyramidal) Function: Related to shape; Motor, Sensory, Processing **Types of Glia:** Glial Cells: Basic support: *glia* = glue **See Figure** Astrocytes: star-shaped glia synchronize activity, remove waste, BBB Radial glia: a type of astrocyte guide the migration & development of neurons Micro glia: small immune cell remove wastes, microorganisms Myelin Production: Oligodendrocytes CNS axons; Schwann cells PNS axons **Astrocytes & Synchrony of Neurons See animation** Astrocytes surround presynaptic terminals Absorb chemicals to inhibit firing at axons Axons then released for synchronous firing **Blood-Brain Barrier See Figure** Endothelial cells of capillary walls joined tightly to form BBB Assisted by extensions (feet) of astroglia. Keeps out viruses, bacteria, toxins Passive crossing: O~2~, CO~2,~ lipophilic molecules, small Active transport system: glucose, amino acids (protein building blocks), vitamins and hormones **Blood-Brain Barrier** Tight junctions of endothelial cells of capillary Glial feet also help produce physical barrier **Neuroconduction** Neuroconduction is communication within a neuron Requires graded potentials or action potentials Action potentials occur in axons. Impulses that travel 10 -100 m/sec **Ions** Ions are charged particles: Anions-negative charge Cations-positive charge Sodium: Na+ Potassium: K+ Chloride: Cl- Calcium: Ca++ Protein Anions: A- **Resting Membrane Potential See Figure for Ion Distribution at RMP** RMP means neuron can respond rapidly to stimulus RMP = -70 mV Semipermeable membrane: prevents Na+ flow into cell (influx) Contains voltage-gated ion channels Protein Anions line membrane Sodium-potassium pump: 3 Na+ ions out /2 K+ ions pumped in **Semipermeable Membrane Figure** Ion Channel in green: Protein molecules; Voltage gated **Contributions to RMP** Concentration gradient: \[Na+\] Out \> \[Na+\] In \[K+\] In \> \[K+\] Out Flow from Hi to Lo concentration: Pressure for Na+ influx Electrostatic pressure: Net negative charge on membrane Opposites attract: Pressure for Na+ influx **Polarization** Depolarization: Excitatory ↓ negative charge inside the neuron EPSP (Excitatory Post-Synaptic Potential) Hyperpolarization: Inhibitory ↑ negative charge inside the neuron IPSP (Inhibitory Post-Synaptic Potential) Repolarization: return to RMP **Nerve Impulses** Graded Potentials: passive, electrical, fast, decremental from source; Not at axon (dendrites, soma) Excitatory or Inhibitory Post-synaptic potentials: EPSP or IPSP Action Potentials: active, electrochemical, nondecremental (constant magnitude) Occur in axons (neuroconduction); Ultimately release neurotransmitters **Na+ & K+ Waveforms See Figure on Action Potential** Red Na+: Influx Blue K+: Efflux **The Action Potential (AP) See Figure of AP** Depolarization exceeds threshold (15 mV) Na+ voltage gated channels open Na+ influx occurs to generate AP K+ channels open shortly after, K+ efflux Repolarization: At peak, Na+ close but K+ stay open Hyperpolarization due to K+ efflux: Refractory period RMP: restored by Na+-K+ pump **Features of Action Potential See Figure** Back-propagate into cell body and dendrites: Increases susceptibility of dendrites to structural changes Fires as all-or-none once threshold depolarization achieved Constant Magnitude: height of waveform unchanging Speed depends on diameter of neuron: wider = faster Travels away from soma: Membrane behind AP is hyperpolarized Generated at Axon Hillock in motor neurons: Hi density of Na+ channels **Refractory Period:** Resists producing more AP Absolute refractory (\~1ms): Na+ gates are firmly closed Relative refractory periods (2-4 ms): Na+ gates are reverting to their usual state K+ gates remain open; Strong stimulus can produce AP **Propogation of Action Potential** AP begins at the axon hillock Na+ ions depolarize adjacent membrane; Membrane behind AP in in refractory period AP travels to axonal terminals **Saltatory Conduction** Myelin sheaths ↑speed to 100 m/s or more No Na+ channels beneath myelin; Nodes of Ranvier: unmyelinated sections (Na+ channels) Saltatory conduction occurs as AP jumps from node to node **Myelin Sheath** Myelin (red): Fatty layer; Insulates Nodes of Ranvier: Na+ gates **Synapses: Neurotransmission Kalat Ch 2** **Neurotransmission:** Communication between 2 neurons Pre-synaptic: releases neurotransmitter Post-synaptic: binds neurotransmitter at receptor site Chemical Synapse: gap between these two neurons **Axonal Terminal See Video in MindTap** The axonal terminal contains vesicles of neurotransmitters (NT) AP reaches terminal → Depolarizes membrane → Ca++ channels open Ca++ influx signals exocytosis (Kiss and Run): Release of NT **Synapse See Figure** Synapse is gap or cleft between neurons: NT passively diffuses across synapse NT bound to post-synaptic receptor Binding changes cell membrane: IPSP (Inhibitory) or EPSP(Excitatory) **Fate of Neurotransmitter** NT dissociates from receptor Reuptake: molecule pumped back into pre-synaptic neuron Catabolism: molecule is broken down At cleft OR In pre-synaptic terminal **Steps in Neurotransmission See Figure** Synthesis of NT: Requires precursor & synthetic enzymes Transport of NT: Requires proteins for transfer in microtubules; Some made at terminal Storage of NT: Vesicles at terminal Exocytosis of NT: AP reaches terminal, Ca++ influx Ligand-receptor binding at post-synaptic membrane: produces change in postsynaptic cell Dissociation from receptor Deactivation of NT: Reuptake & catabolism **Deactivation of Neurotransmitter** Reuptake: molecule pumped back into pre-synaptic terminal eg, 5HT Catabolized: broken down OR Stored in vesicle for future release Catabolism can also occur at cleft eg, ACh **Ligand-Receptor Binding** Receptors are protein molecules that bind NT (the ligand): Found in membrane of post-synaptic cell Autoreceptors are on pre-synaptic cell; inhibit NT synthesis/release Many have 7 trans-membrane spanning regions Fast Receptor (ionotropic) Slow Receptor (metabotropic) **Ionotropic Receptor See Figure** Fast Receptors: quick start (10 ms) Short duration (30 ms) Ion Channel as part of receptor Localized effect on membrane Nicotinic: Na+ channel NMDA: Ca++ channel GABA-A: Cl- channel Ionotropic synapses are used for quick events like visual stimulation, muscle movements, etc. **Metabotropic Receptor** Slow receptor: late start (30 m) with duration up to hours Activates G-protein inside membrane; G-Protein activates second messenger system Opens or closes ion channels Changes protein production Activates chromosomes in cell Neurotransmitters: DA, NE, 5HT, some Glut, GABA Metabotropic events: taste, smell, pain **Neuropeptides See Table** Metabotropic effects utilize a number of different neurotransmitters Neuropeptides are often called neuromodulators; Release requires repeated stimulation Released peptides trigger other neurons to release same neuropeptide Diffuse widely and affect many neurons via metabotropic receptors **Electrical Synapse: Gap Junction** Classic Chemical Synapse is most studied Gap junctions are electrical synapses: Cells share an ion channel **Post-synaptic Potentials** EPSP: Excitatory, graded depolarizations IPSP: Inhibitory, graded hyperpolarization In 1960s Eccles used microelectrodes to measure postsynaptic potentials; Can add up or summate to produce AP **Summation of EPSP/IPSP** Temporal Summation: occurring in short time → AP Spatial Summation: arriving from different locations → AP Depends on which gets to axon hillock first. Axon hillock site of AP generation **Cleft or Net?** Nervous system as net or individual cells? Ramón y Cajal: Stains show one neuron separate from another: synapse Sherrington inferred several properties of synapses Delayed transmission; temporal summation; spatial summation **Neurotransmitters** **Neurotransmitters: History** Otto Loewi: stimulate vagus nerve → ↓HR Collected fluid applied to second heart → ↓HR Nerves send messages by releasing chemicals (neurotransmitters) at synapse: Vagustuff (Ach) Elliot (1905): adrenaline mimics SANS Suggested that synapses use chemicals to link neurons **Types of Neurotransmitters** (NT = neurotransmitter) Amino acids (aa): acidic, amine (-NH) Monoamines: nonacidic, amine Acetylcholine: small molecule, similar to aa Purines: adenosine and derivatives Peptides: long chains of amino acids (polypeptides, proteins) Gases: soluble **Criteria for Neurotransmitter** 1\. Synthesized in neuron 2. Catabolic process and enzymes 3\. Stimulations of target cell mimics application of chemical **Synthesis of Neurotransmitters** Neurons synthesize NT from precursors in the diet Cauliflower and milk → choline Protein rich meals → tryptophan Synthetic pathways compete for enzymes, maintain at homeostasis Smaller NT synthesized in presynaptic terminals, close to release point **\ ** **Amino Acid NTs: Glutamate See Figure** Glutamate: major excitatory NT in CNS Sites: ubiquitous Function: Learning, Memory Receptors: NMDA (Ca++ channel) AMPA (Na+ channel) Kainate Drugs: dissociative anesthetics: NMDA blocker Ketamine **Amino Acid NTs: GABA See Figure** GABA: major inhibitory NT in CNS Gamma amino butyric acid Precursor: Glutamate Sites: many, amygdala Function: inhibition, anxiolytic, anti-seizure Receptors: GABA~A~ (Cl- channel) Drugs Sedative Hypnotics: EtOH; Barbiturates Anxiolytics: benzodiazepines (BNZs: Xanax, Ativan) **Endorphins (ß-EP) See Figure** Endogenous morphine-like Opioids: polypeptides Dynorphins, Enkephalins, Endorphins ß-EP = beta endorphin Precursor: POMC & others Site: spinal cord, PAG, reward systems Function: analgesia, euphoria, social facilitation, impair memory, endocrine regulation Receptors: mu, kappa, delta Deactivation: catabolic enzymes Drugs: Opiates are opioid agonists Heroin, Morphine, Oxycontin, Fentanyl **Acetylcholine (ACh) See Figure** Precursor: choline Sites: NMJ, PANS, ANS ganglia, basal forebrain, basal ganglia, hippocampus Function: movement, conserving energy, memory, REM sleep Receptors: muscarinic (heart, CNS) (4 types) Nicotinic (NMJ) (5 types) Fate: catabolism at cleft by AChE **Cholinergic Agonists** Nicotine: nicotinic receptor agonist (Locks channel open) Muscarine: muscarinic receptor agonist α-Latrotoxin: Induces massive ACh release (black widow venom) Physostigmine: AChE Inhibitor **Cholinergic Antagonists** Atropine: blocks muscarinic receptor *Atropa belladonna (deadly nightshade)* Anticholinergics can be hallucinogenic Botulinus Toxin: Inhibits the release of Ach *Clostridium botulinum* a-Bungarotoxin: Prevents channel opening *Bungarus* snake venom *d*-Tubocurarine: Prevents ACh receptor channel opening Curare -- paralyzes motor end-plate **Deactivation See Figure** Monoamines (DA, NE, 5HT): Reuptake Ach: AChE (catabolized at cleft) **Dopamine (DA) See Figure** Precursor: tyrosine Catecholamine monoamine Sites: nucleus accumbens, subanstia nigra, ventral tegmentum, mesolimbic, mesocortical Function: movement, reward systems, schizophrenia, endocrine regulation Receptors: D1,D2: movement, schizophrenia D3, D4, D5: schizoprhenia, minimal movement Fate: Reuptake & catabolism by MAO (monoamine oxidase) Drugs: psychostimulants Amphetamine, Cocaine Methylphenidate **Norepinephrine (NE) see Figure** Precursor: tyrosine (aa); DA Catecholamine monoamine Sites: SANS targets, locus coeruleus Function: arousal, mood Receptors at SANS: α1:vasoconstriction α2: autoreceptors β1:cardioselective β2: bronchodilator Fate: Reuptake & catabolism by MAO Drugs: psychostimulants Amphetamine, Cocaine **The Heart** HR is an index of autonomic arousal: Consider how drugs could affect this PANS: ACh → muscarinic receptors → ↓HR SANS: NE → β~1~ receptors → ↑HR **Serotonin (5-HT) see Figure** Precursor: tryptophan Indoleamine monoamine Sites: Raphe nuclei Function: mood, impulse control, pain modulation, sleep, carbohydrate intake Receptors: 5-HT~1A~-5-HT~5~ (15 receptors) Fate: Reuptake & catabolism by MAO Drugs: Antidepressants: SSRIs Hallucinogens: LSD **Cannabinoids See Figure** Sites: central & peripheral Anandamide: endogenous ligand Function: pain modulation, anti-emetic, euphorogenic, psychodelic, anti-cholinergic Receptors: CB1 (CNS); CB2 (Peripheral) 2-AG receptors on presynaptic neurons or GABA Drugs: THC active ingredient of marijuana **Terms in Pharmacology** Agonist: a drug that mimics or increases the effects of a neurotransmitter Antagonist: a drug that blocks or takes away from the effects of the neurotransmitter Affinity: ability of a drug to bind a receptor Intrinsic Activity: the degree to which the drug activates the receptor once bound **Example: DA** AMPT: can block synthesis DOPA: can increase amount synthesized MAOIs: antidepressants, block catabolism Reserpine: causes leaky vesicles Amphetamine: increases release Cocaine: blocks reuptake, TCA also Haloperidol: blocks D~2~ receptor **Psychotropic Drugs** Drugs that cross the BBB and change Affect, Behavior, Cognition Most are lipophilic, small molecules: Fat soluble, allows passage through biomembranes **Drug Classifications** Psychostimulants Depressants Hallucinogens Narcotics Therapeutic: Anti-depressants; Anti-psychotics **Psychostimulants:** Enhance catecholamines (DA, NE) Reduce fatigue, enhance vigilance; Focus attention Induce paranoia, hallucinations, anorectic Drugs: Cocaine Amphetamine Methylphenidate **Depressants:** Facilitate GABA Inhibit → disinhibit at low doses Anti-seizure Anxiolytic Drugs: Anxiolytic: Benzodiazepines (BNZ) Sedative/Hypnotic: Alcohol (EtOH) **Hallucinogens:** Variety of mechanisms Distortion in perception, cognition Enhance monoamines: LSD (5-HT), mescaline (catecholamines) Cannabinoid agonists: THC (marijuana) Anti-cholinergics: Atropine Dissociative anesthetics (block NMDA): Ketamine **Narcotics:** Bind to opioid receptors Induce sleep (narkos), analgesia, euphoria Drugs: Opium, Morphine, Heroin **Therapeutics** Anti-depressants: Enhance monoamines SSRIs -- 5-HT TCAs & MAOIs -- monoamines Antipsychotics: Block DA Chlorpromazine Haloperidol **Hormones & Behavior:** Glands secrete blood borne molecules **Hormones** Chemicals secreted by glands and conveyed by the blood to influence other organs Produced by endocrine glands Coordinate long lasting changes: Growth Sexual differentiation Metabolism **Classes of Hormones** Protein & peptide hormones (amino acids) Thyroid hormones (contain iodine) Monoamines (NE, DA, EPI) Steroid hormones (cholesterol based): Four carbon rings; Pass through membrane (lipophilic) Nuclear receptors → gene transcription **Endocrine System See Figure** Hypothalamus Pituitary Target gland **Hormone Release** Hypothalamus (HT): neural control center for endocrine system Pituitary: master gland controlled by HT Anterior pituitary; Posterior Pituitary Target gland: peripheral organ Responds to hormone if receptors present **Anterior Pituitary** Adenohypophysis contains glandular cells cells that secrete hormones Corticotrophs: ACTH → adrenal cortex Thyrotrophs: TSH → thyroid Gonadotrophs: FSH, LH → gonads Lactotrophs: PRL → mammary glands Prolactin promotes milk production Somatotrophs: GH → somatic growth (Growth Hormone) **Posterior Pituitary** Neurohypophysis: extension of HT tissue, secretes hormones OTC: Oxytocin controls uterine contractions, milk release, sexual climax. AVP: Vasopressin constricts blood vessels and raises blood pressure; decreases urine volume **Adrenal Steroids** Released from Adrenal Cortex Glucocorticoids: Cortisol; Stress hormone, mobilizes glucose, anti-inflammatory Mineralocorticoids: Aldosterone; Regulates salt balance **Sex Steroids:** Gonadal Testes in men Ovaries & corpus luteum in women A matter of ratio Serve as precursors for each other: P4 → T2 → E2 **Sex Steroids: Androgens** Androgens: testosterone (T2) Build muscle, promote body hair Sexual arousal, aggression Source is testis and adrenal gland T2 → DHT: potent androgen T2 → ~aromatase\ enzyme~ → E2 (Aromatase: converting enzyme) **Sex Steroids: Estrogen (E2)** Estrogens: estradiol (E2) Source is ovaries Secondary female characteristics (breasts, hips) Verbal memory Masculinizes hypothalamus? Creativity? Protect against schizophrenia? **Sex Steroids: Progesterone (P4)** Source is corpus luteum Prepares uterus for pregnancy Affects mood Anesthetic Thermogenic **Hormones** Thyroid Hormones (T4; T3): metabolism, prevent mental retardation (Necessary for post-natal development) Growth Hormone (GH): somatic growth Melatonin (MLT): regulates sleep Insulin: regulates glucose entry into cell CCK: satiety hormone Angiotensin (AII): regulates blood pressure **Glands** Pineal → Melatonin MLT Thyroid → T3, T4 Adrenal → Cort, Aldo Ovary → E2, P4 Testis → T2 Pancreas → insulin Kidney → Angiotensin II