NEUR 414 1st Edition Exam 2 Study Guide Units 3 and 4 Unit 3 Brain Imaging CT adv non invasive easy to do dis no function PET inject tracer ex radioactive glucose cells take up the glucose radioactive redish areas know what areas the patient is using a little invasive getting okay spatial resolution not the best very bad temporal resolution time frame resolution MRI get structure not function Hydrogen atoms add radio frequency pulse unmatched atoms spin to proper way then turns off and flip other way MRI converts signal to image non invasive fMRI used a lot instead of looking at atoms looks at bold signal hemoglobin binds oxygen molecules whatever parts of the body need oxygen hemoglobin releases it from blood the change of having oxygen to being deoxygenated is what an fMRI picks up limitations not looking at normal activity looking at usage of oxygen in that area getting an increased bold single only means theres an increased activation could be leading to excitation and inhibition good spatial resolution good temporal resolution not great b c relying on neurons needed that oxygen measuring indirect effect to look at if neurons are active EEG actually measuring synchronized neural activity recording form cortex b c its closest to skull not able to record things farther in like hippocampus activity limitation going to see who ever has the most activity and if its synchronized not going to be able to see other neurons out what are you measuring neural activity very good temporal resolution disadv poor spatial resolution may neurons for one electrode small changes could get lost in the noise advant non invasive Intracellular comes in and stimulates schaffer collateral and then records in CA1 looks at both intra and extra recordings extracellular measuring fieldEPSPs EPSP after volley you re looking at the change in ion flow via axon potential goes into neuron record ions moving into cell via extracellular area where you are is become not as positive negative goes down b c of this measuring pos ions moving away from you can measure amount and speed of the depolarizing determines how much of that positive ion that is being pulled away can get a look at how many neurons were depolarized big thing to look at is the slope length of slope is indication of how close you are to the cell the closer you are the longer the line slope line is ind of where you are in relation to the neuron now if this was intracellular it flips now slope goes up Water Maze probe trail remove platform and look to see if animal swims to where it was both quadrant and annulus are done during a probe trail adv well characterized dis extremely stressful stress hinders memory Fear Conditioning put animal in environment and either look around or listen to sound and then give it a shock put it in different box and see if its scared of evniro or scared when cue is done cued tone is played at Cued conditioning cued fear conditioning sound is played while you get foot shock DO NOT NEED HIPPOCAMPUS both at the same time CS tone from auditory cortex and thalamus info is sent to the amygdala as same time CS info is coming in US shock somatosenosry cortex and thalamus send info to amygdala conversing of both pathways in amygdala outputs to generate proper motor behavior freezing amygdala sees this information again and knows to freeze fear has been generated delay of conditioning paradime Context put animal in environment and then give it a food shock does it remember enviro being related to shock only talk about CS pathway speaker is wrong sensory input looking at room goes to thalamus information can go to neocortex to hippocampus lateral nucleus or CEc lateral nucleus and CEc in amygdala what pathway does brain use both depends on situation lesion train animal on this fear conditioning and then lesion brain hippocampus don t show any freezing neocortex don t show any freezing now lesion before training cut out either one and animals learn just fine tells us theres two different pathways one is dominant and the other is not wants to use neocortex to hippo if it can but if those two regions are lesioned it can use the other pathway in the absence of hippo adv learning occurs at a specific time 1 time learning dis 1 time learning don t have acquisition curve can t look at whats happening during the learning process Eyeblink Conditioning associating some stimuli that causes you to blink pathway depends on if hippo dependent or not trace first CS then US trace hippocampal dependent and need neocortex delay DON T NEED IT can can cerebellum regulate delay conditioning dependent on this and brain stem Cerebellar Output cell bodies in purkinje cell layer and dendrites axons reach out to other layers dendrites fan like Cerebellar Input bluish looking in pic come into molecular layer and wrap themselves in dendrites and making multiple synaptic connections strong input on a few purkinje cells not going to have small area activation but strong Cerebellar Anatomy thinking of purkinje cells have fan like dendrites these are going straight across through all of them making few synaptic contacts but with a ton of them CS information comes in via mossy fibers activating granule cells and then activating parallel fibers US comes in via climbing fibers activated and then have strong input on purkinje cells that generate a motor output both CS and US come in at the exact same time as result have activation of the exact same symaptic contacts and purkinje cells and can get modification of the purkinje cells when you activate a single mossy fiber you activate a single granule cell may be enough to activate a purkinje cell not a parallel fiber Unit 4 Aplysia memorize structure Habituation decrease response to repeated stimulation sensitizaiton when a strong stimuli increases the response to another stimuli Receptors in skin when stretched loose a little bit of ability to detect things in close proximity to them olfactory exeperiences plasticity Memorize the pathway through the hippocampus Perforant pathway to dentate gyrus mossy fibers to CA3 schaffer collaterals then CA1 Neocortex information goes from layer 5 to 1 2 3 and then to 5 6 Know Hebbian plasticity A and B persistently firing together A s efficiency increases B Experience expectant Plasticity happens when we are young many neurons are decreased as we learn to walk talk and move experience dependent adult learning induced plasticity Enriched rearing looked at brains of mice who were