Multiple Choice Flashcards
Downs Syndrome
- Risk increase with mother’s age
- Have 3 copies of chromosome 21
- Characteristic disfigurement, mental retardation, other health problems
- Up to 50% of DS patients die in childhood because of cardiac, kidney, digestive, and immune problems
- 15 x more likely to get leukemia
– Decrease density of axon and dendritic branching, decreased dendritic spines.
- Link to Alzheimer’s Disease.
Epileptic auras
Seizures often preceded by an aura, such as a smell, hallucination, or feeling
suggest the epileptic focus
warns of an impending seizure
Regeneration CNS and PNS
Regeneration is virtually nonexistent in the CNS of adult mammals and unlikely, but possible, in the PNS
Schwann cells promote regeneration
Ogliodendroglia block regeneration
Neurotransplantation
Neurotransplantation = **transferring stem cells to treat neurological damage/disease. **
Fetal Tissue: fetal substantia nigra used to treat MPTP treated monkeys and was successful
Stem Cell:
- adult
- embryonic
- umbilical cord
Experimentally used in Parkinson’s patients, so far so good
Explicit vs. Implicit memory loss
explicit memories – conscious memories
implicit memories – unconscious memories, as when H.M. shows the benefits of prior experience
Korsakoff’s Syndrome
Amnesia, confusion, personality changes, confabulation (making up history/memory), and physical problems
comparable to medial temporal lobe amnesia in early stages
Mostly alcoholics get this.
Medial Temporal Lobe Amnesia
semantic memory may function normally (general info) while episodic memory does not (events experienced)
They can remember facts, but not personal history.
Long Term Potentiation (LTP)
- induction
- maintenence
- expression
only occurs if presynaptic firing is followed by postsynaptic firing
the effects are greatest in areas involved with learning and memory
Chimeric Figures
Chimeric Figures = split pictures
Task for split brain patients, each hemisphere of a split-brain can learn independently and simultaneously
Apraxia
difficulty performing movements when asked to do so out of context, can perform them spontaneously
associated with damage to left hemisphere
Cross Cueing
Non-neural communication between the two hemispheres
How: After incorrect response (LH), shakes head and frowns (RH), changes answer (LH)
Or, after choosing incorrect response with right hand (LH), left hand (RH) grabs the hand away.
Cortical Asymmetries in Language
All of these function primarily in left hemisphere
• Planum temporale (Wernicke’s Area)
– Temporal lobe, posterior lateral fissure
– Language comprehension
• Heschl’s gyrus - primary auditory cortex
• Frontal operculum (Broca’s Area)
– Near face area of primary motor cortex
– Language production
Transcortical Sensory Aphasia
A speech disorder in which a person has difficulty comprehending speech and producing meaningful spontaneous speech
Caused by damage to the region of the brain posterior to Wernicke’s area.
Analytic, motor and linguistic theory (left hemisphere)
Analytic: left is analytic, right is synthetic, vague and untestable
Motory: Left controls fine movement, left damage may produce speech and motor deficits
Linguistic: Primary role of left is language
Genetics and Schizophrenia
Clear genetic basis
– Inherit an increased risk for the disorder
Multiple causes
– Several different chromosomes implicated
– Associated with various early insults
-But not deterministic: identical twin chance is 50%
Appears that interference with the normal development of susceptible individuals may lead to development of the disorder
Positive and Negative Symptoms
POSITIVE SYMPTOMS
thought to be due to overactivity of several types of dopamine receptors
NEGATIVE SYMPTOMS
• thought to be due to brain damage (structural abnormalities)
- degree of brain damage (temporal and frontal lobes) correlated with severity of negative symptoms
- frontal lobes seem particularly affected
Blood flow in mood disorder
Medial Frontal Regions: showed largest difference between control and depressive groups= 12% decrease in blood flow!
Drevets et al.
– Found increase in metabolism in amygdala and medial thalamus (both control emotional behavior) in depressed individuals
– If antidepressant treatment is successful, you see decrease in amygdala neural activity
– However, if antidepressant treatment is unsuccessful • do NOT see decrease in amygdala neural activity
Genetics and depression
Diathesis-Stress Model
• Inherited genetic susceptibility (diathesis) + stress = depression
-Concordance (genetic inheritance) rate is higher for bipolar than unipolar
Diathesis-Stress Model
Inherited genetic susceptibility (diathesis) + stress = depression
• Support is indirect
– Depressed people tend to release more stress hormones
– Fail dexamethasone suppression test
– normal negative feedback on stress hormones not functioning
Types of Anxiety Disorders
- Generalized – stress and anxiety in the absence of a causal stimulus
- Phobic – similar to generalized, but triggered by a stimulus
- Panic disorders – may occur with other disorders, but also alone
- Obsessive-compulsive disorders (OCDs) – obsessive thoughts alleviated by compulsive actions
- Posttraumatic stress disorder
Animal Models of Anxiety
• Assess anxiolytic potential of drugs - assume that defensive behaviors are motivated by fear, and that fear and anxiety are comparable
– Elevated-plus-maze: time in open arms indicates less anxiety
– Defensive-burying: More time burying, more anxiety
– Risk-assessment test: Time freezing and assessing risk indicate anxiety level
Balint’s Syndrome
-Ventral stream “where” damage.
– Bilateral damage to parietal lobes
– Simultanagnosia: Patients have tunnel vision; eyes stay focused on any small object that happens to be in foveal vision & ignores all other objects in vicinity
Simultanagnosia = can’t see simultaneous objects.
Binding Problem
Binding:
- How separately represented pieces of information about one thing are later brought together
- Acheived by synchronized oscillation of neural groups in the brain (basicaly doing the wave)
Attention and Consciousness
Selective Attention (cocktail phenomenon)
Although by no means conclusive, current evidence suggests that…
Top-down attention and perceptual consciousness are two distinct but often allied processes with distinct neurobiological processes.
As a consequence, it will be important to carefully distinguish the neuronal correlates of consciousness from the neuronal correlates of selective attention (Tse et al., 2005).
Organization of sensory system
Sensory areas of the cortex:
- primary = input mainly from thalamic relay nuclei
- secondary = input mainly from primary and secondary cortex within sensory system
- association = input from more than one sensory system, usually from secondary sensory cortex
Somatosensory Agnosias
Produced by large lesions to parietal cortex
- asterognosia = inability to recognize objects by touch
- asomatognosia = inability to recognize parts of one’s own body
Mnemonics: Soma = body
Astero = Astero-glide (touchy touchy :D)
Somatosensory Pathways
The somatosensory system is a diverse sensory system comprising the receptors and processing centres to produce the sensory modalities such as…
touch, temperature, proprioception (body position), and nociception (pain).
The sensory receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal organs, and the cardiovascular system.
Nociception looks like no-ice = pain!
Proprio = body position, such as being propped up.
Types of Brain Tumors
- gliomas = arise form glial cells, half of all brain tumors
- meningiomas = encased or attached to meninges
- infiltrating = grow through surrounding tissue
- metastatic = transfer of cells from one region to another
Meta = bringing tumor to the next level - THE BRAIN!
NMDA Receptors and Glutamate
LTP is mostly commonly studied where NMDA glutamate receptors are prominent
The NMDA receptor (NMDAR), a glutamate receptor, is the predominant molecular device for controlling synaptic plasticity and memory function.
Closed Head Injuries
- Brain injuries due to blows that do not penetrate the skull – the brain collides with the skull
- Concussion – when there is a disturbance of consciousness following a blow to the head and no evidence of structural damage.
- While there is no apparent brain damage with a single concussion, multiple concussions may result in a dementia referred to as “punch- drunk syndrome”
– Contrucoup injuries – contusions are often on the side of the brain opposite to the blow (contra = opposite)
• Contusions – closed-head injuries that involve damage to the cerebral circulatory system. A hematoma forms.
Punch-Drunk Syndrome
While there is no apparent brain damage with a single concussion, multiple concussions may result in a dementia referred to as “punch- drunk syndrome”
Tardive Dyskinesia
Some antipyschotic drugs produce a motor disorder called tardive dyskinesia
It is a disorder resulting in involuntary, repetitive body movements. The involuntary movements are tardive, meaning they have a slow or belated onset.
This neurological disorder frequently appears after long-term or high-dose use of antipsychotic drugs
Apoptosis
Programmed cell death
Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation.
Neural Degeneration and Regeneration
- Various neurochemicals can block or limit neurodegeneration
- Apoptosis inhibitor protein – introduced in rats via a virus
- Nerve growth factor – blocks degeneration of damaged neurons
- While regeneration does not normally occur in the CNS, experimentally it can be induced
