Ch.7, Research Methods Flashcards
Neuropsychology
study of brain related to behavior, with emphasis on humans
3 primary modern ways of studying the brain
historically: relied on brain injuries, post-mortum data, and animal lesions
NOW
chemical lesions: through drugs/temporary neurotoxins
Genetic lesions: shutting down the target gene of interest
Noninvasive imaging: MR, EEG, FMRI, PET
Molecular genetics: genome sequencing
“Frozen addicts case”
- 1982 Santa Clara Medical centre: patients coming in that appeared to have parkinsons: couldn’t move or speak but appeared alert
- George carillo admitted he was on synthetic heroin
- Turns out Barry Kidston was trying to synthesize MPPP but instead made demerol (MTPT) since it was an opiod for pain relief: but ended up keeping the temperature wrong
- MPTP on its own: not toxic, but when it interacts with astrocytes and serotonergic neurons that have MAO, it becomes MPP+ which kills dopaminergic neurons in dopaminergic system
- Death of dominergic neurons in substantia nigra= Parkinson’s-like symptoms
GOOD THING: developed animal models of PD for study
Isomers
molecules that have the same chemical formula but different bond arrangemnent
How to conduct animal studies
exploiting species typical behavior in the design
Spanswick’s Hippocampal Rat Experiment
- control group
- Rats with ADX: adrenalectomy (adrenal glands are part of the endocrine system, secrete cortisol for stress in humans and corticosterene in rats) = 50% reduction in dentate gyrus neurons
- Rats with ADX and an enriched environment (better social interaction, diet, excercise, etc.)
Procedure - TRAINING PHASE Introduced rats to two distinct contexts to see if they would remember them for 10 minutes over two days.
TESTING PHASE
-Control group did
-ADX group couldnt tell the difference/remember it
-ADx group with enriched environment performed the same as control
RESULTS: environment can mediate affects of loss of dentate gyrus neurons, facilitate neurogenesis,
Two divisons of the hippocampus
Located in temporal lobe
Dentate gyrus: It processes spatial memories and helps you make decisions. Hippocampus proper (cornu ammonis): This region works to form memories, then organizes and stores your memories
DAPI stain
used for staining DNA nuclei: DAPI, or 4′,6-diamidino-2-phenylindole, is a fluorescent stain that binds strongly to adenine–thymine-rich regions in DNA, blue
Morris swimming task
Richard Morris
1. Place Learning Task: rats were first placed in pool, located plank, then pulled out of water. 15 min interval between trial. uses distal cues from room, tests long-term memory due to 15 min wait
2. Matching to place task: rats did the same thing, but we’re placed back in the water almost immediately, tests working memory, distal cues
3. Landmark learning task: plank in diff location every time, but marked by a landmark cue (like a picture taped to the pool wall); now uses LOCAL cues, not distal, and requires spatial navigation skills not testing any kind of memory
Probe trial: remove the plank, they will look for it in original spot (almost like a validity check?)
Skilled reaching task
-uses rats bc they are very dexterous
-animal model of stroke for study
rats had to reach in between narrow gap for food: depending on the brain area they had damaged, they may or may not be able to do this
-Movement was broken down into segments and scored seperately to see how diff neurological problems influenced it
Why modify the brain to see how behavior is altered?
- Test hypotheses about how the brain affects behavior
- Develop animal models of disorders to test pharmaceuticals
How to manipulate brain in animal modes
whole animal manipulations: food, environment, etc.
Manipulations to specific brain regions: brain lesions (chemical, genetic, surgical); stimulation/inhibition using electrical, drugs, or genetic methods
Stereotaxi apparatus
machine that is fixated on head to get very precise location of brain region
used in brain surgery
X axis: moves it lateral/medial
Y axis: moves it anterior/posterior
Z axis: moves it dorsal ventral
Phineas gage
metal rod through frontal lobe
indicated to scientists that FL is crucial in personality, since Gage had problems with impulse control, vulgarity, irrespnsibility, and being very rude afterward
Penfield and Brain stimulation
founded the MNI in 1934
worked on patients in surgery
did awake electrical stimulation
no pain receptors in cortex so easy to do
with every stimulation, recorded what patients fielt or said
Gave us detailed brain mapping
Objectives of brain stimulation
enhancing or blocking neural activity and observing the behavioral effects
Deep brain stimulation
FACILITATE/INDUCE
allows us to look at structures very deep in the brain
-used for cases of parkinsons/schizophrenia as an absolute last resort
-mobile device that provides low voltage current into specific targeted region of the brain
could be used to stimulate striatum/basal ganglia
Transcranial magnetic stimulation
-very superficial, only 3-4mm down
-can do it on clinical and non clinical samples, major benefit
Magnetic coil is placed over brain to induce magnetic field, which either induces or inhibits behavior in that area