Psych 202 1st Edition Lecture 14 Biological psychology I Genetics the Nervous System and Neurotransmitter Processes Some orienting concepts on genetics in psychology o Human body cell chromosomes DNA genes o What is genetics A heredity of specific characteristics Eye color hair color skin color E g Mendel s peas mathematical laws In plants animals etc there is something that controls the characteristics that will show up in offspring Processes involved in turning genes on and off All cells in our body are genetically identical yet our body contains cells which are dramatically different Genetic switching The way in which genes regulate the encoding of proteins and the way the specific environment turns on or off a genetic switch Polygenic effects Mendel s rules of dominant and recessive characteristics are not useful for looking at many genes simultaneously o Chromosomes Composed of DNA wrapped up around other materials DNA is composed of sediments of genes Genes are pieces of DNA which is in chromosomes Genes expression what controls the switching of a gene on or off DNA is wrapped around a cluster of proteins called histones Genome all genetic material itself Epigenome layer of stuff that is above the genome Unwrapping of DNA and is exposed Gene expression requires unwrapping of DNA When methyl chemical groups attach to the DNA there is reduced accessibility to genes Repression of gene expression can occur through DNA methylation Epigenetic modifications of genes and the impact for human health cancer stress reactivity etc o Genes Affect Behavior Behavioral Genetics Methods Twin Studies Compare MZ and DZ Twins MZ identical DZ two separate fertilized eggs Adoption Studies raised in separate environments and examine the specific role on environment vs genetics in behavior These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute o o Heritability degree to which a specific characteristic intelligence creativity height etc is affected by genes in a population group Can t pinpoint specific role in one individual has to be out of the group Gene Expression Can Be Modified Manipulating Genes Pick your Mouse or person Alcohol preferences video Manipulating Environments Mother Nurture article 2 kinds Anxious genetically Calm genetically Cross fostering taking calm mouse and have it be raised by anxious mother The environment overrides the genetics Genes are turned on and off partially by changing environments Epigenetics again stress reactivity Genes get turned on and of from environmental factors IQ FADS 2 fatty acid and mother s milk Under some conditions breast feeding increases intelligence How Are Neural Messages Integrated into Communication Systems Three systems are coordinated 1 The Central Nervous System CNS Brain and spinal cord 2 The Peripheral Nervous System PNS connects the CNS to the rest of the body through subdivisions 1 The Somatic Nervous System which acts on skeletal muscles the muscles attached to bone Sensory Neurons Afferent Neurons transmit somatosensory information from peripheral sensory organs to CNS and 2 Motor Neurons Efferent Neurons bring motor informational commands from CNS to the muscles SAME Somatic neurons are afferent motor neurons are efferent 2 The Autonomic Nervous System which acts on visceral muscles e g heart arteries gastrointestinal tract and glands e g salivary sweat The Sympathetic Nervous System is activating Fight or Flight Freezing fleeting The Parasympathetic Nervous System is deactivating Rest and Digest Endocrine System The Endocrine System Communicates Through Hormones Actions of the Nervous System and Endocrine System Are Coordinated The hypothalamus is a critical integrating structure as will be explored in the next lecture on brain structure and function Stress and The HPA Axis HPA stands for hypothalamus affects pituitary gland which affects adrenal glands high levels of freely circulating cortisone H P CRF released P A CTH released Example of Stress Response The consequences of dysregulation in the human stress response high amounts of cortisone circulating High amount of abdominal fat Building up of arterial plaques Increase chance of heart disease and stroke Reducing effectiveness of immune system Inhibits hippo genesis and memory function cognition Neurons Nerves and Tracts Neuron principle cell that transmits information to cells Nerve group of axons of many neurons that come together in cable of fibers wire and send info to other places in CNS contract Tract Peripheral Nervous System consists of entire set of nerves cranial and spinal Cranial nerves Neurons are specialized for communication What happens at the 3 parts of neuron Dendrites Collect information from adjacent neurons Cell Body In tegration Axons Part of the cell where decision is made to send an action electrical potential to another cell Some neurons have myelin sheaths protects and insulates and increases speed of neural connections and nodes of ranvier What are those A node of ranvier is the space between two myelin sheaths on an axon where depolarization and action potentials occur A Myelin sheath Is made from glial cells Provides insulation for axons Speeds up neural transmission by causing action potentials to jump across the nodes of ranvier called saltatory conduction Saltatory conduction produces faster neural speed and thereby increases how quickly effects at the synapse can occur Myelin sheaths are made from glial cells Neurons are supported by glial cells but are different Glial Cells Called Glia Outnumber Neurons 10 1 in CNS Most commonly occurring cell glial Form Myelin Sheaths Blood Brain Barrier Help Supply Nutrients to Neurons etc Different Varieties Different Functions Illustration 3 Types of glial cells and their structures and functions Oligodendrocytes Schwann Cells Astrocytes deliver nutrients and sugar to cells