Why botherFacial expressionsIntelligenceSexual orientationAlcoholismPsychological disordersWeight gainAggressive behaviorsThe BasicsChromosomes contain DNASequence of DNA=geneA gene contains information on hereditary characteristicsWe have 46 chromosomes22 paired autosomal chromosomesplus 2x (female)or 1x and 1y (male)From DNA to ProteinDNA RNATranscription-DNA seperates and a copy of one strand is made to be RNARNAProteinTranslation- every 3 bases becomes an amino acidGenetic termsHomozygous and heterozygousDominant and recessivePTC and tasteA gene for a bitter receptorHomozygous recessive (tt)-cant taste PTCHeterozygous(Tt)-somewhat unpleasantHomozygous dominant (TT)-tastes horribleSex-linked genesThe genes on the sex chromosomeUsually on the xFragile x syndrome-mental retardationRed-green colorblindnessDucherine muscular dystrophyHemophiliaSex-Limited genesPresent in both sexes but has an effect in only one sexGenes for chest hair, breast sizeGenes are turned on under influence of sex hormonesHeritabilityEstimate of how much of the variance in a characteristic is due to differences in heredityHow do we know about heritability?Twin studiesIdentical twins share exact DNAThe more DNA they share, the more likely you are to share the traitSuggests that the specific trait is heritableAdoption studiesThe big problem: prenatal developmentTwin studies-MZ twins share chorion and blood supply so could be genetics or could be prenatal environmentAdoption studies- prenatal environmentAnother problem with estimating heritabilityGenes predispose you to behaviors and to different treatment by othersWhat started out as potentially small effect of genes end up having a huge behavioral result…leading to overestimation of heritabilityCan environmental influences affect a trait with high heritabilityYes, inherited or genetic doesn’t equal unmodifiable!EvolutionNatural selectionOnly heritable traits move on to next generationEvolution-improvement?Based on environment, genes are continued through generations of they aren’tEpigeneticsChanges in phenotypeCells of the nervous systemChapter 2.1•Mammalian CellsCytoplasm and organellesNucleus-DNAER-Rough for translation, smooth for transport, modification of proteinsGolgi-finishing touches on new proteinsMitochondria-energy productionLysosome-Clean upPlasma membrane-semi-permeable barrier•Cell membrane of neuronsPhospholipid bilayer-2 layers of fat molecules that are free to float around one anotherSemi-permeable-water, oxygen, carbon dioxide move freely;•Cells of the nervous system•Neurons-70 billion in just the cerebellum!•Glia-way more of these cells then neurons, play vital roles in functions of the nervous system•8.5-10x more glia than neurons!•Neurons•Cells that receive and transmit information•Basic unit of the nervous system•Many neurological diseases are due to damage to a group* of neurons–a group of neurons in the CNS is called a nucleus–PD•NeuronThe cell body is called the somaThe branches coming off the soma are called dendrites, they receive informationThe axon transmits the information through the neuronAt the tips of the axon are axon terminal buttons, goes to the dendrites of other neuronsThe myelin sheath convers the axon, its insulation for the axon• Motor neuron.For example, The cell body (soma) lives in the spinal cord. The axon is part of a nerve in your body. The terminals are in your muscles.• Somatosensory (touch) neuronFor example, The soma lives in a dorsal root ganglion, just outside the spinal cord. Most of its length is an axon. It has specialized endings in the skin, and its terminals are in the spinal cord.•Synapse: where 2 cells “meet”The 2 neurons don’t actually touch when they transmit informationPresynaptic-before the synpasePostsynaptic-after the synapsesynaptic cleftefferent-going away fromafferent-going towards•Dendritic spinesSmall protrusions on dendritesLocation of most excitatory synapses•Glia (or “Glial cells”)Exchange chemicals with neuronsOligodendrocytes-makes myelin sheath in CNSSchwann cells-makes myelin sheath in the PNSMicroglia-repair, remove wasteRadial Glia-guide cell and axon migration during developmentAstrocyte-perform many functions, can wrap around synapses to contain environment, wrap around a bunch of axons, can make blood vessels get bigger to get extra nutrients to the neurons there, used in blood brain barrier•Blood Brain Barrier-surrounds blood vessels that are feeding the brain•Endothelial cells w/ tight junctions surrounding capillaries•Astrocytes surround endothelial cells•BBB keeps out–viruses & bacteria–chemicals–nutrients•BBB lets thru–small uncharged molecules, like oxygen–fat-soluble molecules (vit A and D, psychotropic drugs)–glucose•Sometimes viruses do enter…Some brain regions have incomplete BBB (on purpose!)•Review: parts of a neuron•Study Questions•Know the different organelles and their functions.•Understand the structure of the cell membrane.•Know the parts of a neuron and their functions. Be able to label the parts of a neuron.•Compare motor neurons & sensory neurons: How are they different from each other & how are they the same? Be able to draw each one. Which one is multipolar and which one is unipolar?•Know the different types of glial cells and their functions. ESPECIALLY which one puts myelin on axons in the CNS and which one myelinates axons of the PNS?•Know the parts of a synapse (presynaptic cell (terminal), postsynaptic cell (dendrite or dendritic spine), synaptic cleft).•Understand the terms afferent and efferent.•What/where is the blood brain barrier? What does it keep out, let in? What are the implications of this for drug use and medicine?•Inquiring minds•Mammalian Cells•Mammalian Cells•Mammalian Cells•Mammalian Cells•Mammalian Cells•Mammalian Cells•Mammalian Cells•Types of neurons•Nolte Fig 1.4Gross Anatomy of the Brain4.1, 4.2Review and transitionParts of neuron?Dendrites, soma, axon, terminals, myelin sheathGray matter versus white matterThe grey matter is the primarily cell bodies and dendritesWhite matter is primarily axonsHumans vs. other mammalsBumps-gyrusSmooth-SameBrain areasChemicals (neurotransmitters)Proteins (channels & receptors)DifferentOverall brain sizeSize of individual partsNeocortex (primates)Olfactory bulb (rodents)Auditory cortex (bats)Muscles and sense organs of forelimbs (monkeys)The BrainForebrainThe cool
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