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Neuro Block 1
Neuro for block 1
80
Medical
Graduate
01/21/2009

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Cards

Term
Frontal Lobe Functions
Definition
Higher Cognitive Function Control of steriotyped movements Control of voluntary movements Motor area for speach
Term
Precentral Gyrus Function
Definition
Primary motor cortex
Term
Opercular Gyrus Function
Definition
Broca's area- speach and writing on left hemisphere
Term
Triangular Gyrus Function
Definition
Broca's area- speach and writing on left hemisphere
Term
Parietal Lobe Function
Definition
Conscious Sensation Somatic Sensation
Term
Postcentral Gyrus Function
Definition
Primary sensory cortex
Term
Inferior parietal Lobule
Definition
Language Compression on left side
Term
Temporal Lobe Function
Definition
Hearing Interpration of Sounds
Term
Superior Temporal Gyrus
Definition
Primary auditory Wernikes's area
Term
Occipital Lobe Function
Definition
Vision
Interpretation of visual images
(visual association cortex)
Term
Limbic Lobe Function
Definition
Emotion
Drives
(5 f's feeding, feeling, fight, flight and F***)
Memory
Term
Amygdala function
Definition
Involved with emotions
Term
Insual Function
Definition
May play a role in olfaction and discriminative touch
Term
Basal Ganglia Function
Definition
Precise control of voluntary movement
Term
Cerebellum Function
Definition
Processes sensory information to regulate movement
Term
Brainstem Function
Definition
Homeostasis, sensory, motor, and autonomic innervation of the head and neck Special Senses
Term
Three basic parts of a typical neuron
Definition

1) Cell Body

2) Dendrites

3)Axon

Term

Details about axon

what organellels are not found here

Definition
Golgi bodies, RER, and ribosomes --> axons cannot synthesize protiens
Term
Two types presynaptic structures where neurotransmitters are released
Definition

1) Boutons/ synaptic end feet

 2) Varicosities

Term

Types of Axons

 Golgi Type 1

Golgi Type 2

Definition

Type 1 are long and projection

Type 2 are short, interneurons, and more prevelent.

Term
Dendrite VS. Axon Branching
Definition
Dendrites many branches merge into a cell body Axons only 1 branch from cell body
Term

Dendrite VS. Axon

 Organelles that they do not contain

Definition

Dendrites- do not contain golgi bodies

 Axon- do not contain golgi bodies, RER, and ribosomes

Term

Dendrite VS. Axon

 Physical characteristics

Definition

Dendrites- Tapers as it goes away from soma, have spines where bulk synaptic reception occurs, Branch profousely

Axon- cylindrical, varicosities, and boutons at terminal end of axon

Term

Dendrite VS. Axon

Mylination

Definition

Dendrite- never

Axon- can be

Term

Dendrite VS. Axon

where do ramification occur

Definition

Dendrite- close to cell body

 Axons- close or far away

Term

Dendrite VS. Axon

electrical activity

Definition

Dendrite- No action potentialm, only graded depolarization and hyperpolarization

Axon- Action potentials

Term

Dendrite VS. Axon

synaptic activity

Definition

Dendrite- mostly postsynaptic, but also may be presynaptic in ( dendro-dendrity synapse)

 

Axon- Presynaptic mainly, but postsynaptic in (axo-axonal synapse)

Term

Dendrite VS. Axon

Energy consumption

Definition

Dendrites- most energy consumption, to bring back to Em of cell after each depolarization or hyperpolarization

 

Axon- low in axon trunck, but may be high in terminals

Term

RER found where?

RER is also known as?

Definition

cell body, and dendrites. NOT found in axonal hillock.

AKA: Nissel Substance

Term

Microfilaments

1) diameter

2) single molecule subunit 

3) role

4) how are they assembled

Definition

1) 5-8 nm diameter

2) actin

3) helps to change cells shape.

4) are assembled in a single helix

Term

Neurofilaments

1)diameter

2)  how are they assembled

3) Associated with with which disease

Definition

1) 10 nm

2) Polar diamer-> non-polar tetramer-> Protofilaments-> Protofibril -> 10 nm neurofilament

3) Alzheimer's Disease

Term

Microtubules

1) diameter

2) how is it polar in axon?

3) subunits?

4) how is assembled?

 5) importance

Definition

1) 20-25 nm

2) possitive end goes toward axon terminus

3) alpha and beta tubulin

4) 13 protofilaments form a hollow tube, and they are polar.

5) Filament important in support for dendrites and axons.

Term
Lipofuscin
Definition
When there is indigestible material in lysosome. Associated with dementia and old age
Term
Why do we need transport system in axons? (4)
Definition

1) soma is site of synthesis of protiens, macromolecules, and organelles -> to get them to Axon

2) Axons are long and stuff won't diffuse there fast enough

3) degraded protiens and vesicules need to come back to soma

4) diffusion to slow

Term

Slow axonal transport:

1) moves in which direction

2) two components and what do they move

Definition

1) anterograde only

2) a) slow- moves microtubules, nuerofilaments and soluble protiens

b) faster component- moves actin, metabolic protiens, and calmodulin.

Term

Fast antergrade axonal transport

two protiens that allow this to happen?

which way do they move?

What do they move?

Definition

A) Kenisin (+). Moves subcellular organellels

B) dynein (-), moves lysomes with stuff that needs to be degraded, recycled membranes, growth factors, viruses, and toxic chemicals

Term
4 Characters of a lipid bilayar
Definition
  1.  impermeable to ions
  2. functions as a capcitor
  3.  creates mebrane potential
  4.  ions flow through channels.
Term
4 ways to open ion channels
Definition

1) Voltage gated

2) Ligand gated

3) Thermally gated

4) Mechanically gated

Term
Nerst equation
Definition

Ex=-RT/zF*ln([Xi]/[Xo])

Ex=-0.058/z*ln([Xi]/[Xo])

Term
Factors that influence net diffusion of ion
Definition

1) Electrochemical Gradient

 2) Conductance of the Channel

Term
Why are ion pumps important?
Definition
They prevent the cell from depolarizing to an equalibrium potentential of 0mv. a state that occurs when cell is dead.
Term
Passive cable properties of neurons
Definition
a excititory depolarization in dendrite spreads to surrounding areas, but it also decays
Term
Active cable proteties of neurons
Definition
action potential
Term
Length Constant
Definition
distance over which the potential falls by 63% from original value
Term
Relationship between membrane resistance and length resistance?
Definition
They are inversely related, the higher the membrane resistance the lower the lenght resistance. The lower the lenght resistiance the faster and AP will travel down an axon.
Term
4 properties of Action Potential (AP)
Definition

1) threshold

2) All-or-none response

3) latency - time between ap and depolarization starts

4) refractory period

Term
What charcteristic about voltage gated Na channels creates refractory period?
Definition
They close after opening.
Term
How do you increase speed of AP?
Definition
Speed dependent on length constant. Can increase it by increasing diameter of neuron or increasing membrane resistance.
Term
Two Em recording techniques
Definition

Intracellular- tells you Em

Patch clamp- gives you currents of each ion.

Term
TTX
Definition
inhibits fast Na+ channels
Term
TEA
Definition
inhibits all sodium channels
Term
Hyperkalemic Periodoic Paralysis
Definition
Muscle weakness. Caused by a mutation in Na+ channels that makes it hard for them to close. These attacks occur more often after eating K+ rich foods like bannanas or excersing. This is because the increased K+ in extracellular fluid makes the muscle Em to drop and hence more likely to fire an action potential.
Term
  • What is myotonia
  • 2 diseases with these symptoms
  • physiological reason why it happens?
Definition
  • difficulty in relaxing a contracted muscles.
  • Thomsen's Disease and Becker's Disease.
  • Cl- channel abnormality, that prevents the channel from opening. This makes the muscle cells very excitble, because hyperpolarizing effect of Cl- is lost.
Term
Two neurons, A and B, each receiving one input from an axon.  Stimulation of this axon leads to NT release from these two nerve terminals.  They have the same amplitude and inputs.  Neuron A fired an A.P. but Neuron B did not. True or False?

1) A's dendrite has a larger diameter than B.

2) A is more excitable than B.

3) A has a higher longitudinal resistance than that of B.

4) A has less density of voltage-gated Na channels along its axon than Neuron B.  

Definition

1) true

2) true; (See curves of excitability; this means that it would need less de-polarization to fire an A.P..  So yes.)

3) False

4) Flase (More Na channels means it is more excitable.)

Term

Epilepsy is an inherited condition caused by increased electrical activity (like increased A.P. firing rate).  30% have a known acquired cause (like head trauma, stroke, tumor).  70% are idiopathic.  Genetic factors are believed to be central.  Which of the following genetic mutations can contribute to epilepsy?

Mutation in channels resulting in…

1) …increased gNa?

2) …decreased gK?

3) …increased gCl?

Definition

1)Yes 

2) Yes

3) No; (Since there's more chloride outside, this means more would come inside, which leads to hyper-polarization!)

Term

Which is true about voltage-gated Na channels?

  1. -it is a transmembrane protein (yes)
  2. -self-inactivate
  3. -glutamate activates it
  4. -blocked by TEA
Definition
  1. yes
  2. yes; leads to refractory period
  3. no, voltage gated
  4. no, only potassium channels
Term
  1. Glutamates role in mind?
  2. Where is it found?
  3. What type of sypnapse is used?
  4. What type of neurons?
Definition
  1. Primary excititory neurotrasmiter of CNS
  2. found all over spine and brain
  3. Asymetrical synapse
  4. Principle outflow nuerons from a brain region
Term
  1. How is Glutamate synthesized in CNS? Major pathway
  2. Minor Pathway
  3. Does it cross blood brain barrier?
Definition
  1. Glutamine is converted to Glutamate by glutaminase
  2. glutamate dehydrogenase allows NH3 and alpha-ketoglutamate combine to form glutamate.
  3. NO
Term
  1. What intiates Glutamate relese?
  2. How does Glutamate get into its vessicle?
  3. How is its activity inhibited?
Definition
  1. Ca+2
  2. VGluT protien uses energy to put glutamate into the vessicle
  3. Inhibited by auto-regulators such as mGluR2 and mGluR3
Term
  1. How is Glutamate inactvated?
Definition
  1. Glutamate is taken up into astrocytes from synaptic space by EAAT.  This channel uses a sodium symport system.
  2. Then glutamate converted to glutamine via glutamate synthetase.
  3. Glutamamine then becomes transported into neuron where it becomes Glu
Term

Three types of Glutamate receptors and describe them.

Definition
  1. AMPA- ionotropic; move both K+ and Na+, but mainly Na+; primary excititory receptor of brain.
  2. Kainate- ionotropic
  3. NMDA- metabotropic.  Needs glycine and AP as well as glutamate to open channel and displace Mg+2 plug to let Ca+2 through. Plays a role in synaptic plasticity.
Term

mGluR's

Definition
  • metabotropic glutamate receptors
  • they are g protien linked
  • in post synaptic cells caused more Ca+2 to enter cytoplasm from sarcoplasmic reticulum or by coupled ion channels.
  • Presynaptic- modulates glutamate release
Term

Excitotoxicity

  1. Define
  2. Diseases it can cause
  3. When it can occur
Definition
  1. When the neuron gets to excited it lets too much Ca+2 into the cell which can cause irreprebal harm
  2. ALS and Huntington's
  3. Also occurs when cell is stavrved for nutrients like O2 and Carbohydrates.
Term
  1. Where are noradrenergic neurons found?
  2. What role do these neurons play?

 

Definition
  1. The hind brain- Pons, medulla oblongate, and midbrain.  AKA ventricular system
  2. Important in arousal of mind and autonomic functions.
Term

Synthesis of norepinephrine

Definition
  1. tyrosine- Tyrosine hydroxylase
  2. DOPA- DOPA decarboxylase
  3. Dopamine- Dopamine beta hydroxlase (found in secretory vessicle)
  4. Norepinephrine
Term
How is norepinephrine synthesis regulated?
Definition
  • The rate limiting enzyme is tyrosine hydroxylase. 
  • The affinity of tyrosine hydroxylase for BH4 is regulated by phosphyralation on specific serine residues. 
  • Increased intracellular Ca+ levels leads PKA to phosphorylate the serines
  • Auto receptors cause cAMP break down--> decreased PKA activity.
  • Also end product inhibition; Norepinephrine leaks out of vesicles and inhibits tyrosine hydroxylase
Term
  1. How does dopamine get into the vessicle?
Definition
VMAT2
Term

Three Mechanisms for norepinephrine release

Definition
  1. Ca+ dependent vesicle fusion
  2. Reverse plasma membrane transport
  3. Dendridic Release of vesicles that is not Ca+2 dependent.
Term
How is free norepinephrine found in the axoplasm?
Definition
  1. leaking out of vesicles VMAT2
  2. what ever is reabsorbed from the synapse
Term
  1. How does alpha2 receptor activity affect norepinephrine production?
  2. How does beta receptor activation affect norepinephrine production?
Definition
  1. decreases cAMP levels in cell, leading to less phosphorylation of tyrosine hydoxylase
  2. increases Ca+2 concentration in cell-> cAMP levels increase -> PKA activity increases.
Term
How is norepinephrine deactivated?
Definition
  1. Diffusion out of synaptic cleft
  2. Reuptake into presynaptic neuron by transporters that use sodium as co-transporter.
  3. Then it is deactivated by 1) MAO or (2) catechol-O-methyl-transferase (COMT) uses SAM.
Term
  1. What does binding of norepinephrine to its receptor result in?
  2. diffrence between alpha and beta
  3. diffrence between alpha1 and alpha2 receptors
  4. What regulates these receptors ability to activate signal transduction and receptor quantity?
Definition
  1. g-protiens
  2. Alpha receptors bind to norepinephrine better than epinephrine.  the opposite is true for beta.
  3. alpha1 are postsynaptic receptors in periphery; alpha2 are presynaptic that inhibit norepinephrine release by breaking down cAMP.
  4. Changes in activation and amount of norephiephrine in the synapse.
Term
  1. What type of transmiter it nuerotensin?
  2. What parts of the brain is it found in?
  3. Can a neuron co-release it with another neurotransmiter?  If yes, than which ones?
Definition
  1. peptide
  2. prefrontal cortex, hypothalamus, and midbrain
  3. yes, only dopamine
Term
Describe creation of Neurotensin and how it is released.
Definition
  1. Peptide is synthesized as a 170 AA chain. The chain also contains another neurotransmiter neuromedin N
  2. The neurotransmiter is then taken down the axon in dense core vessicles
  3. Ca+2 dependent release, but requires high action potential frequency as well.
  4. Release occurs anywhere, not just the active zone
  5. Activation of dopamine autreceptor enhances its release.
Term

Inactivation of Neurotensin (3 ways)

Definition
  1. Nonselective peptidases
  2. Diffusion
  3. internalization of receptor to cell body of post synaptic cell.
Term
Describe neurotensin receptor
Definition
  1. G protien coupled
Term
  1. Anadamide is made up of which molecules and how are they linked?
  2. Where is it found?
  3. What is an agonist for the molecule?
  4. What does it modulate?
Definition
  1. arachidonic acid and ethanolamine linked by an amide bond
  2. Striatum, limbic cortex, hippocampus, and cerebellum
  3. Who got that gonja? THC
  4. feeding, sleep, bp, balance and posture, memory, mood, and other neurotransmitters
Term
Describe anadamide synthesis
Definition

Made the way you like it, fresh (synthesized on demand)  by two enzymes

  1. Transcyclase- it is activated by high intracellular Ca+2 levels. to make NAPE
  2.  NAPE cleaved to anandamide by phospholipaseD
Term
Anadamide Receptor
Definition

Canaboid receptors

  • Are g protien coupled
  • Almost always presynaptic
  • inhibits Ca+2 channel opening, hence inhibits neurotransmitter release. 
Term

How does anadamide work?

when is it increased? 

Definition
  • it is activity dependent, and retrograde in nature
  • made when neuronal activity is high
  • binds to a presynaptic receptor that inhibits Ca+2 influx, inhibiting neurotransmiter release
  • Increased durng stroke seizures and brain trauma.
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