CHAPT 5 Psychological Psychology Study of brain behavior and brain cognition Phineas Gage mid 1800s worked for Transcontinental Railroad very conscientious Injury rod through his head buy recovered but personality had changed Because a drunkard and womanizer Physiological Psychology Brain has plasticity Brain is responsible for higher setters as sophisticated as personality cognition Infer what s going on in the mid by looking at the brain Scientists are reductionists break everything down into the smallest units relationship between the brain and behavior and the brain and Gross level top to down the whole Cellular Level down to up Neurons The Neuron Cell body Dendrites Receptors pick up signals then transmit them across dendrites and soma Soma similar to all the other cells in the body the branches pick up signals form other neurons have receptors dendritic spines Electricity spreads across the dendrites then to the soma Local potentials graded potential individual bursts of electricity Electrical signal Signals Axon hillock where axon and soma meet Makes decision based on how much electricity has come through the dendrites and soma Summation occurs if enough electricity reaching axon hillock at the same time neuron sends signal down the axon All or None Principle If not wipes it clean send electrical signals from soma to axon terminal Axon Membranes in axon open and close Ions charged particles come in and out Leads to an electrical signal Come from Glial Cells glue support cells auxiliary cells Help brain and nerve keep their functions Make signals travel faster Myelin sheath Action Potential adaptive located around the nerve cells layer of fat over axon adaptive In axon K Potassium inside Na Sodium outside When the neuron gives the signal membranes open up sodium flows in and potassium goes out Brain communicates through electrical signals Ca Calcium flows in at axon terminal Nodes of Ranvier saltatory conductor gaps between glial cells Instead of the signal being propagated in the axon saltatory conduction with myelin sheath Causes vesicles containers holds neurotransmitter Goes to membrane Vesicles open and neurotransmitter defuses form them into a small gap Gaps is called synapses and react with receptors on dendritic spines Neurons look differently and have many different structures and make many connections Synaptogenesis brain makes connection with other nerve cells at infancy Certain nerve cells making the right connections and getting stronger Others are not making connection and they die Grow more neurons than you need Apoptosis the cells death Neurotransmitters NTs Sherrington Law 100 substances being released form axon terminal Classical Neurotransmitter widespread distribution and Sherrington Law is true for each neuron there is one and only one neurotransmitter FALSE Lock Key right transmitter for right receptor Neurotransmitter could be excitatory or inhibitory Drugs can manipulate the transmission neurotransmitter increase the activity of neurotransmitter Agonist Antagonist Acetylcholine the nervous system Curare reception from acetylcholine Causes paralysis decrease the activity of neurotransmitter peripheral nervous system brain and spina cord all neurons that goes through Acetylcholine antagonist blocks receptor on motor tissues so they can t pick up the Epinephrine adrenaline endocrine system hormone system both hormone and Neuro muscular junction neurotransmitter When travels through neuron neurotransmitter When released form adrenal gland hormone Excitatory or inhibitory When it comes across synapse and receptors react could be either more or less active More or less likely to send neurotransmitter Norepinephrine found in the brain Leads to REM sleep rapid eye movement Leads to the feeling of pleasure reward Motor pathway control movement Voluntary control of movement Dopamine found throughout central nervous system Meso limbic pathway related to schizophrenia Reward pathway anything you do something that furthers your survival sends a signal of pleasure Dopamine and norepinephrine flowing though Help the individual and species to survive Dopamine agonist ex methamphetamine cocaine Nonadaptive part drugs Drugs can mimic Tolerance level the effect wears down therefore needing to intake more Homeostasis balance in the body Neurons want a certain amount of activity running Receptors on synapse get depleted and dry out Cannot get more than a certain amount of activation in that part of the brain Withdrawal symptoms depression Everything hurts Receptors small and no pleasure Agony until receptors come back to normal level of activity Depression linked to low level of activity in pleasure pathway Giving cocaine to someone who is depressed doesn t get them high because their receptors are already depleted Anti depressants take forever to work because it must build up receptors in the brain Serotonin non REM sleep Found throughout the central nervous system Modern anti depressant drugs Serotonin antagonist Psychedelic drugs work on serotonin pathway Exert inhibition Alcohol inhibit their inhibitory neurons disinhibition GABA major inhibitory neurotransmitter in the central nervous system Disinhibition removal on inhibition Behavioral outcome Act out things that people want to do but is inhibited to do so Opium piston stamen Morphine and codeine Endorphin chemically identical to morphine Brain engineered around drugs Anandamide bliss THC receptor identical to marijuana Nervous System Peripheral every neuron not in the brain spinal cord Central the brain spinal cord Peripheral Nervous System PNS Somatic Nervous System skeleton Conscious part voluntary Automatic Nervous System no control Automatic Nervous System 1 Sympathetic response fight or flight Pupils dilate salivary glands stops sweating begins Raises heart rate and blood pressure Releases glucose and fat for high energy Decreases digestive processes Immune system vestigial response 2 Parasympathetic response rest or digest opposite responses Both are antagonistic to one another complimentary Central Nervous System CNS Brain Spinal Cord Ways to Study Brain Activity 1 Lesions destroying a particular brain region 2 Stimulation alternating stimulus 3 EEG 4 Single cell recording placing an electrode on a neuron instead a brain area What one neuron does Huber Wiesal 5 Brain imaging CAT static image of particular region PET dynamic image inject with radioactive glucose fMRI oxygen flow Spinal Cord Ascending
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