Brain and Behavior Test 1 Study Guide Lecture 1 Genetics DNA is transcribed to RNA RNA is translated to protein Proteins workhouses of the cell determines body development by forming part of body structure and by serving as enzymes catalysts that regulates chemical reactions in the body Mendel s law of inheritance govern what traits we have one gene copy from each parent Genes autosomal sex linked usually linked to X chromosome or sex limited present in both sexes but expression is contingent upon exposure to factors such as hormones Epigenetics changes in gene expression based on environment without modification of DNA sequence can be active at certain time of day or point in one s life central to learning and memory and is a likely explanation for differences between MZ twins Ex of epigenetics in HLG rats becoming high grooming mothers Transgenic mutant gene to study a particular gene see how gene change gene knocked out affect trait behavior Twins MZ twins 1 egg split share identical genetics prenatal environment DZ twins 2 eggs made at same time share 50 of DNA same prenatal environment Similar traits between twins are often confused to be genetic similarities but are actually a result of a shared prenatal environment Genes do NOT produce behavior but produce proteins that increase the probability that a behavior will develop under certain circumstances Multiplier effect behaviors may be overestimated and increased due to positive feedback ex temper tantrums Lecture 2 Nerve Cells People used to believe cells grew into each other rather than the fact that the nervous system was comprised of individual cells Neurons like other cells contain membrane nucleus mitochondria ribosomes and ER Cell Nucleus contains chromosomes strands of genes Mitochondria performs metabolic activities and provides ATP fuel for cell Mitochondrial Disease muscle hearing vision learning neurological heart etc problems Mitochondrial Eve mitochondria has own mtDNA is unilateral and passed on unchanged Ribosomes synthesizes new protein molecules ER thin tubes that transport newly synthesized proteins to location Membrane phospholipid bilayer with protein molecules as gates channels that uses active transport for things against concentration gradient and facilitated diffusion for things with concentration gradient glucose or oxygen Proteins make you who you are one missing or off AA can cause Cystic Fibrosis tumor suppressor neurological disorders Alzheimer Parkinson Huntington or membrane problem Neurons Soma cell body that contains nucleus mitochondria and ribosomes Presynaptic terminals axon terminals The Squirter releases chemical to next neuron Axon thin fiber responsible for transmitting nerve impulses toward other neurons organs or muscles some are covered by myelin sheath Afferent to Efferent from Dendrites postsynaptic terminals branching fibers lined with synaptic receptors that receive messages from previous neuron Interneuron bipolar relay neuron contained within single structure soma in middle Sensory neuron unipolar highly sensitive at one end to a particular stimulus soma in middle Motor neuron multipolar makes muscles move soma in spinal cord at top Pyrimidal cell widely branching dendrites soma around middle Afferent axon bringing information into Efferent axon carrying information out Neuron to neuron signal 1 Dendrites receive signal 2 If enough signal current goes through soma 3 The current can trigger a signal at base of axon 4 Signal travels down to axon terminal 5 This releases neurotransmitters into synaptic cleft 6 Signal received by dendrites of next neuron Glia other major component of nervous system a Astrocytes synchronize activity by wrapping around presynaptic axon terminal and waiting for enough signal from axon for one pulse temporal or spatial b Microglia garbage men remove waste or harmful material c Oligodendrocytes in CNS and Schwann cells in peripheral NS build myelin sheath Myelin sheath fat and protein membrane around axon that insulates and speeds reaction pain is not myelinated d Radial Glia guide migration and growth of neurons during embryotic development Blood Brain Barrier gooey membrane that blocks harmful material from entering brain uses proteins for active transport of energy oxygen chemicals hormones amino acids and nutrients glucose in and out of brain Brain neurons generally do not regenerate so VERY dangerous for things to sneak across BBB genital herpes rabies psychotrophic drugs penicillin chemotherapy work peripherally Lecture 3 Action Potential Nerve impulse is like domino effect NOT like electric wire electricity carries signal down axon to synapse chemical transmission at synapse to next neuron Neuroanatomy of cockroach leg Cockroach has sensory neuron under each hair Music stimulates motor neuron touch stimulates sensory neuron Nerve impulse closer to the brain affects you more quickly than from farther Membrane maintains electrical gradient by charge concentration and concentration gradient by ion concentration by being selectively permeable with ion channels protein complex For every 2 K ions in cell 3 NA ions are transported out Resting potential inside of cell has more potassium K outside has more sodium NA At resting potential NA channels closed and K channels a bit open Polarization difference in electrical charge inside and outside of cell Sodium NA wants to enter cell by electrical AND concentration gradient Potassium K is thus pushed out by concentration gradient pushed in by electrical gradient Threshold of excitement level above which any stimulation produces a massive depolarization Depolarization uses electricity to fire neuron decrease polarization in cell making inside more and outside more At the end of depolarization there is more Sodium and less Potassium in cell Refractory period after neuron fires like a toilet Absolute refractory period sodium channels close and cell cant fire for 1 ms Relative refractory period requires more than normal stimulation to fire for 2 4 ms All or none law action potential is independent of stimulus neuron either fires or it doesn t Anesthetics novicaine xylocane block sodium channel stopping the cell from firing Hyperpolarization increased polarization making inside more and outside more needs a greater impulse to fire Usually results from GABA inhibitory neurotransmitter from alcohol or depressants Thin axons conduct action potentials at 1 m s thick axons can increase conduction to 10 m s Myelin
View Full Document
Unlocking...