Neurological Disorders: Tumors & Seizures, CV accidents, TBI
What is the difference between a hemorrhagic and ischemic stroke?
Hemorrhagic: burst vessel
Ischemic: blockage causing lack of O2
True or false: immunization against AB plaques in Alzheimer's showed no improvement in cognitive functioning compared to baseline.
False- improved cognitive functioning
What is bioavailability, and what route of administration has the best bioavailability in the shortest time?
Bioavailability: amount of drug in blood
IV administration gives 100% bioavailability
What are the stages of addiction?
Acquisition --> recreational or social use --> habitual use --> abuse --> compulsive use/addiction
Describe the negative feedback loop in the HPA axis.
Hypothalamus secretes corticotropin-releasing hormone, which stimulates the pituitary gland to secrete ACTH. This signal is sent to the adrenal gland, which secretes adrenaline. Adrenaline loops back to the hypothalamus and inhibits it from continuing to secrete CRH, and shuts down the circuit.
Based on observed patient health outcomes, is a shunt or a stent procedure more beneficial for stroke patients?
Shunt- more people continue to have strokes with stents
Parkinson's is characterized by a loss of dopamine cells from the degradation of the nigrostriatal pathway. Surviving dopamine cells are at risk of becoming ____ ____, which cause _____ _____ ______.
Lewy Bodies, Lewy Body Dementia
A new chemotherapy drug has an ED50 of 10mg and an LD50 of 5,000mg. Is this drug is relatively safe or dangerous?
Safe- large margin and high lethal dose.
What is the difference between positive and negative reinforcement, and what are examples related to addiction?
Positive: increasing behavior by adding reward (drinking alcohol to get drunk/feel good)
Negative: increasing behavior by removing something as a consequence (drinking alcohol to avoid withdrawals)
What are the two main variables being studied in a diathesis-stress model?
genetics and environment
How does chemotherapy treatment for brain tumors work, and why does it result in hair loss?
Chemo kills all rapidly dividing cells, which includes hair. It also inhibits angiogenesis, which is induced by vascular endothelial growth factor secreted by tumors.
What vitamin deficiency causes Korsakoff's, and what typically is the reason for this?
B1/thiamine; alcoholism
Alcohol acts on which neurotransmitter to boost what ion?
GABA; Cl-
Describe the difference between appetitive and consumatory trackers, and identify which trait is more at risk for addiction.
Appetitive: looking for reward, sign-directed- more prone to addiction because the stimuli becomes more rewarding.
Consummatory: taking the reward, goal-directed.
Both healthy controls and depressed patients received an injection of dexamethasone, which boosts cortisol. In healthy controls, a boost of cortisol was observed following injection, which then subsided back down to baseline. In depressed patients, the cortisol boost did not come down, implying a faulty HPA axis negative feedback loop.
Describe interictal inhibition in seizures.
Between seizures, there a surge of GABA, which suppresses brain tissue in certain regions. These areas become under-active and can result in depressive episodes between seizures.
Discuss the role of parkin and its implications in Parkinson's.
Parkin transfers misfolded proteins to proteasomes, where they are destroyed. When parkin is defective, these misfolded proteins accumulate and cause alpha-Synuclein to occur, which is cytotoxic.
Describe direct vs. indirect binding, and antagonistic vs. agonistic drugs.
Direct binding: competes for the same binding site as the neurotransmitter
Indirect binding: allosteric/noncompetitive- the drug has a separate binding site than the NT, and the drug binding site changes the same of the whole receptor to prevent NT binding.
Antagonistic: decreases NT signaling
Agonist: boosts NT signaling
Discuss how A and B states change in the opponent processing theory in healthy people and drug addicts.
Non-addicted: the A process spikes when the drug is initially taken, and comes down gradually with the B process opposing it. There is then a small spike in the B process (hangover).
Addicted: the B process spikes as soon as context cues are detected, and counteracts the effects of the A process when the drug is taken; this means the addict is taking the drug to avoid the B process, not to feel the A process.
What is chronic traumatic encephalopathy, and what are some neurbiological and behavior outcomes?
CTE: neurodegeneration from repeated head trauma
-leads to tau protein accumulation: Alzheimer's
-reduced brain volume and enlarged ventricles
-mood disorders and executive dysfunction
Describe how precursor proteins APP give rise to ß-Amyloid plaques.
2. APP is cut apart: ß-secretase cuts off tail, gamma-secretase cuts off head
3. ß-Amyloid is formed from cut APP
Identify the 5 types of drug classification categories,, which neurotransmitter system they target, and list some examples of drugs in these classes.
1. Sedatives: alcohol, barbiturates: GABA A
2. Stimulants: cocaine, AMPH: DA
3. Opiates: heroin, morphine: endogenous opiates/endorphins (mu, delta, kappa)
4. Hallucinogens: LSD, DMT: 5-HT
5. Cannabis: THC: cannabinoid receptors
Describe the behavioral dysregulation model, and how it changes in addiction.
Saliency of a stimulus drives desire and interacts with memory, but self-control (OFC) inhibits desire.
In addiction, saliency is increased significantly and control is reduced. Memory is also focused strongly on salience of drug.