Exam 1 Flashcards
Who created the neuron doctrine? What did he study to do this?
Cajal (in 1890’s)
Using golgi stain on brains of new born animals
What are the 4 rules of the neuron doctrine
- Neuron fundamental structure in brain
- Terminal of one axon communicate with dendrites of another (specialized sites-later termed synapses)
- Connections are specific
- Dynamic (unidirectional) polarization
True or false; Cajal won the nobel prize for his work making the neuron doctrine
True
True or false; every cubic inch of cerebral cortex has about 10,000 miles of nerve fiber in it
true
True or false; the number of neurons in the brain is about 100x greater than the population of earth
False; it is about 30x greater (~180 billion)
A typical neuron is wired to about how many of its neighbors in the cortex
~1000-2000
True or false; most cortical neurons don’t converge much with other neurons
False
There is a HUGE amount of convergence between cortical neurons. This is how humans can process sensory information.
What is the first layer of the cerebral cortex called? What is situated here
Molecular layer
mostly axons
What is the second layer of the cerebral cortex called? What is situated here
External granule layer
granule (stellate) cells
What is the third layer of the cerebral cortex called? What is situated here
External pyramidal layer
primary pyramidal cells
What is the fourth layer of the cerebral cortex called? What is situated here
internal granule layer
main granular cell layer
What is the fifth layer of the cerebral cortex called? What is situated here
internal pyramidal layer
dominated by giant pyramidal cells
What is the sixth layer of the cerebral cortex called? What is situated here
multiform layer
all types of cells; pyramidal, stellate, fusiform
What are the three major cells types of the cerebral cortex
Pyramidal
Granule
Fusiform
What kind of major cerebral cortex cell is associated with corticospinal projections, and are major efferent cells
Pyramidal cells
What kind of major cerebral cortex cell is associated with short axons, intra cortical processing, excitatory release of glutamate and inhibitory release of GABA
Granule cells
What kind of major cerebral cortex cell is least numerous and gives rise to output fibers from cortex
Fusiform cells
Most output leaving cortex, leave from what layers?
V and VI
Spinal cord tracts originate in which cortical layer? What about thalamic connections?
Spinal-V
Thalamus-VI
Where do most incoming sensory signals terminate in cortex
Layer VI
Most intracortical communications are associated with which layers?
I, II, III
True or false; all areas of the cerebral cortex have extensive afferent and efferent connections with deeper structures of brain (thalamus, basal ganglia, etc)
True
True or false; cortical neurons cannot change their function regardless of demand changes
False; if demand increases, cortical neurons can change their function to meet needs
True or false; the association cortex which integrates information from diverse sources makes up a large % of the cortex
True
What would a lesion in the association cortex cause?
Subtle and unpredictable phenotypes
Elaboration of thoughts, executive functions of behavior, working memory, and processing of emotion are all associated with what area of the cortex
Prefrontal association area
What is the limbic association area control?
Behavior
Emotions
Motivation
Analysis of spatial coordinates of body, area of language comprehension, recognition of faces, and naming objects are all associated with what area of the cortex
Parieto-occipitotemporal association area
True or false; auditory, visual, and somatic all feed into Wernickes (language comprehension) area
True
True or false; the angular gyrus which functions as a higher order visual signal processing area is located just in front of Wernickes area
False; it is located just behind Wernickes
Loss of ability to solve complex problems, inability to string together tasks, loss of morals, inappropriate social responses, and decreased aggression are all results of what surgical technique
Prefrontal lobotomy
After identifying an object/face; projections from fusiform gyrus to amygdala allow person to what?
Gage emotional significance to what they just saw
What is Capgras syndrome? What are patients with this like?
Connections between fusiform gyrus and amygdala are damaged rendering patient unable to tie emotion to objects or people
Patients don’t recognize family and think they are impostors (this only occurs when visualizing them, i.e. would still recognize a voice)
What is the best known form of specific language impairment?
Dyslexia
What % of the U.S. population is affected by Dyslexia
5-17%
What happened to Phineas Gage (railroad worker)
A tamping iron went through his face, skull and brain
Survived, but damaged ventromedial region of both frontal lobes
Personality was severely altered, post-accident irresponsible, impudent
What do ventromedial regions of the frontal lobes involved with?
Basic biologic regulation, emotional processing, social cognition and behavior (ventromedial regions connected with subcortical nuclei like amygdala and hypothalamus)
High concentrations of serotonin S2 receptors in monkey’s ventromedial regions of their frontal lobes are associated with what? What about monkeys with low concentrations in this area?
Monkeys with socially adapted behavior
Low concentrations=aggression and socially uncooperative
In ~95% of the population, general interpretive functions of Wernicke’s and angular gyrus as well as speech and motor control are more developed in which hemisphere
Left
True or false; if the dominant hemisphere of a person’s language is damaged at a early age, the brain will delegate the work to the healthy hemisphere
True, this is an example of neuroplasticity
If a person is left or mixed handed, what probabilities will there be for which hemisphere they will show lingual dominance
Left-70%
Right-15%
Both-15%
If a person is right handed, what probabilities will there be for which hemisphere they will show lingual dominance
Left-96%
Right-4%
Both-0%
Generally, what actions/interpretation of information are delegated to the left hemisphere
language based functions interpreting symbols, speech, written words analytical functions (math)
Generally, what actions/interpretation of information are delegated to the right hemisphere
Music
non verbal visual experiences (body language)
spatial relations
What is the function of the corpus callosum? Is there a limit to where it can work?
Bilateral communication between hemispheres
Yes, anterior portions of the temporal lobe are non connected by corpus callosum, they’re connected by the anterior commissure
What does the anterior commissure connected?
Bilateral communication between anterior portions of the temporal lobe (amygdala-emtional response transfer)
Why would a surgeon sever the corpus callosum
To prevent the spread of seizures in patients with severe epilepsy
True or false; the allocortex is made up of the archicortex and paleocortex
True
What 3 cortical layers make up the hippocampus
I, V, VI
What 3 cortical layers make up the dentate gyrus
I, IV, VI
What kind of memory is the hippocampal formation associated with?
Declarative-making declarative statements of memory (Episodic or daily memory, and semantic or factual info)
How does the hippocampus have a function in episodic memory
It has bidirectional connections with parahippocampal regions
True or false; memory functions can be localized to specific regions of brain
True; i.e. hippocampus and hippocampal gyrus
How does memory form?
Caused by changes in sensitivity of synaptic transmission between neurons as a result of previous mental activity “memory traces”
True or false; “memory traces” can occur at all levels of the nervous system from spinal cord to cortex?
True
What is positive memory associated with? What about negative memories
Positive- associated with facilitation
Negative- associated with habituation (suppression)
What is the difference between short term, intermediate long term, and long term memory
Short- last seconds to minutes
Intermediate- last days to weeks
Long- last years to lifetime
What is the NMDA receptor associated with? What does it bind?
Associated with synaptic learning/memory
Binds glutamate
True or false; memory has stages and is continually changing
True; long term-plastic changes
True or false; long term memory and declarative/reflexive memory involved the same neuronal pathways
False; they do not
What is conscious memory? What part of the brain does it involve?
Memory of details of an integrated thought
Memory of surroundings, time relationships
Involves the hippocampal gyrus (evaluation, comparison, inference)
What is Hyperthymestic syndrome? How many people worldwide have this? What is unique about their brain
Person has total recall of every memory in their lives
Only 10 people have been identified
Have large caudate nucleus
True or false; reflexive memory is associated with conscious motor activities
False; associated with unconscious motor activities
What is the difference between episodic and semantic memory? What area of the brain do they both involve
Episodic- remembering daily episodes
Semantic- factual (2+2=4)
hippocampus and parahippocampal areas
Hippocampus and temporal lobe areas thought to process newly learned things before transferring to cortex
True or false; the hippocampus may store long term memory for weeks before transferring to cortex
true
Bilateral removal of hippocampus is associated with what
profound deficits in memory
loss of capacity to form new long term memories
loss of ability to transfer most types of learning from short term to long term
What memory capability is spared following bilateral lesions of temporal lobe (hippocampal formation)
Learning tasks that have two things in common - tasks tend to be reflexive and involve habits, motor, or perceptual skills - do not require conscious awareness
What is habituation?
Decrease in response to report benign stimulus
What is sensitization (pseudo conditioning)
Strengthening of responses to a wide variety of stimuli following and intense stimulus
What is imitative learning very important in?
Learning language (mirror neurons)
Where are mirror neurons found?
Ventral premotor cortex and inferior parietal lobe
What are the two kinds of associative learning
Classical conditioning and Operant conditioning
What is operant conditioning?
When a dog learns if it poops in the house it will be punished
True or false; if you don’t use neurons you lose them
True; during young life especially neurons are looking to make meaningful connections and if they do they will flourish, if they do not, they will perish
What is the possible % of the cortex you can lose if you don’t use it?
50%
True or false; storage of memory is associated with structural changes in the brain
True; increase in both # of transmitter vesicles and release sites, increase in synaptic connections (neural plasticity)
If protein kinase M zeta is blocked, what else is blocked?
Long term memory
Difference between learning and memory
Learning- process by which we acquire knowledge about the world
Memory- process by which knowledge is encoded, stored and retrieved
True or false; all learning is beneficial
False; some can be detrimental
True or false; in extreme cases learning can cause psychological disorders
true
Difference between implicit memory and explicit
Implicit- unconscious memory
Explicit- conscious memory
What area of the brain is the general area that controls overall excitement
Reticular excitatory area (reticular formation of pons and midbrain)
In diffuse stimulation of the cerebrum via the thalamus, where do rapid short lasting signals come from? What is released? What about long lasting?
Short- magnocellular releasing ACH
Long- from many small nuclei releasing glutamate
True or false; the reticular excitatory areas transmit excitatory signals to spinal cord
true; maintains tone of antigravity muscles
If the reticular excitatory area (reticular formation pons) was cut what would you expect to see from a patient
Coma
What promotes wakefulness
pontomesencephalic cells located in locus ceruleus and dorsolateral pontine tegmentum
What kind of cells do you find in the dorsolateral pontine tegmentum (associated with wakefulness)
dopaminergic cells
noradrenergic cells
Both the caudal mesencephalic cholinergic (ACH) cells and oral pontine reticular formation (glutaminergic cells) are associated with maintaining what?
Wakefulness
True or false; caudal mesencephalic cholinergic (ACH) cells and oral pontine reticular formation (glutaminergic cells) contribute to wakefulness primarily through ascending projections to the thalamus
true; they also communicate with hypothalamus and basal forebrain
In regards to wakefulness; thalamocortical projections contain what neurotransmitter
Glutamate
In regards to wakefulness; basal forebrain projections contain what neurotransmitter
ACH
The reticular inhibitory area, located in the medulla in reticular formation inhibits the reticular excitatory area via what kind of projections?
Serotonergic projections (raphe)
True or false; the norepinephrine system (locus ceruleus) is the most wide spread-generally stimulatory neurohormone
true
True or false; the dopamine system (substania nigra, arcuate nucleus) can increase or decrease neuroendocrine behavior
true
What system is involved in the raphe nuclei involved in
Serotonin system (usually inhibitory, induction of sleep)
What system is the gigantocelluar involved in?
ACH system (usually excitatory)
What area of the brain is most important in episodic memory
hippocampus
In hyperthymestic syndrome, what brain structure is enlarged?
Caudate nucleus
What would be the result of bilateral ablation of the hippocampus
retrograde amnesia
What cortical neurons fire when we observe someone doing something
mirror neurons in ventral premotor area
What neural circuit is associated with emotion?
papez circuit
What is the Papez circuit
anatomic basis for connections of limbic system with higher cortical areas (bidirectional) (emotion)
The cortex, cingulate gyrus, hippocampal formation, amygdala, mammillary body, hypothalamus, and thalamus are all involved in what circuit?
Papez circuit (emotion)
What are the 2 basic emotional states
Arousal and Conservation
Which basic emotional state is associated with sympathetic functions, steep tropistic gradient
Arousal
Which basic emotional state is associated with parasympathetic functions, apathy, decreased muscle tone
conservation
What is the major output pathway and one of the central elements of the limbic system?
Hypothalamus
What part of the limbic system is associated with behavior control (reward and punishment) control of vegetative functions (body temp, osmolaity, motivational drives, thirst and hunger) endocrine control (ant. pituitary) and some immune function
Hypothalamus
True or false; the hypothalamus has vegetative controls like cardiovascular regulation, regulation of body temp, body water, uterine contractility and milk ejection
true
The lateral hypothalamus is associated with what?
Thirst, eating, increased level of activity, rage and fighting
The ventromedial nucleus of the hypothalamus is associated with what?
satiety, and tranquility
Periventricular nucleus (central gray) part of hypothalamus is associated with what
fear and punishment reactions
Extreme anterior and posterior regions of the hypothalamus is associated with what
sexual drive
Where would you find reward centers
along medial forebrain in lateral nuclei of hypothalamus (positive reinforcement)
Where would you find punishment centers
central gray around aqueduct of sylvius in mesencephalon extending into perioventricular zones of hypothalamus and thalamus (negative reinforcement)
True or false; the medial forebrain pleasure circuit is self stimulated
true
Where is pleasure perceived in the brain
medial forebrain pleasure circuit
What is associated with “want more, like less” “tolerance, craving, withdrawal”
addiction
True or false; endogenous opiate receptors have highest density in cerebral cortex
false; they have lowest density here
Highest density in amygdala and hypothalamus
What is Kluver-Bucy syndrome
Bilateral ablation of amygdala
Loss of fear
Excessive sexual drive
What constitutes about 1/2 the volume of the brain and outnumber neurons 10:1
Glial cells
What are the 3 major glial cells in the CNS
Astrocytes
Oligodendrocytes
Microglia
True or false; glial cells can proliferate throughout life
true; injury stimulates
True or false; glial cells do not function with neurons often
false; they are partners in practically every function
Which glial cell is closely associated with blood vessels and neurons
Astrocytes
Which glial cells store virtually all the glycogen present in the brain
Astrocytes (contain enzymes for metabolizing glycogen)
True or false; astrocytes can supply fuel to neurons in the form of lactate derived from glucose
true (glucose is taken up by astrocytes and converted to lactic acid)
Are astrocytes permeable to K+
yes
Do astrocytes have similar NT receptors of identical neurons
yes (astrocytes have high infinity for uptake of large # of NT like glutamate and GABA)
Which glial cell is associated with Ca+ waves causing changes in activity in nearby neurons
astrocytes
What glial cells, is present in all areas of the CNS, makes and sustains myelin
Oligodendrocytes
True or false; oligodendrocytes are involved in pH regulation
true; they contain most of the carbonic anhydrase in brain
True or false; oligodendrocytes are involved in Cu metabolism
false; they are involved in iron metabolism
contain ferritin, transferritin
What are considered the macrophages of the CNS
Microglia
What makes up about 20% of the glial cells in the brain, mediates immune responses
microglia
What is the most effective antigen presenting cell in the brain and rapidly activates by injury where they rapidly proliferate
microglia
