Kaelyn BildstenPat Ladue

Brooke Gainer

The supportive tissue of the nervous system including the network of branched cells in the central nervous system

Neuroglia cells also maintain homeostasis and form myelin

Neural support cell that forms the epithelial lining of the ventricle in the brain and the central canal of the spinal cord.

Gives rise to the epithelial layer around the choroid plexus.

Glue between neurons, providing structural and metabolic support

Provides nutrients to the nervous tissue Maintains extracellular ion balance Plays a principal role in repair and

scarring of the brain and spinal cord

Astroclasts maintain the blood-brain barrier

Regulates nutrients and dissolved gas concentrate

Absorb and recycle neurotransmitters Form scar tissue after bodily injury

Surround and insulate the long fibers (the axons) through which the nerves send their electrical messages.

Form the insulation of the axons exclusively in the CNS

Structural organization by tying clusters of neurons together

Forms myelin sheath that surrounds axons structural framework

Protects axons from subsequent injury: implications for deficits in multiple sclerosis

Produced by Schwann cells

Acts as insulation to increase the rate of transmission of signals

Protects of the nerve fiber Formed of protein If an axon is severed, the myelin sheath

allows the axon to grow back along the sheath, allowing the axon to return to normal

Unmyelinated axons do not regenerate

Part of the axon that is myelinated Internodes consist of an axon or

multiple axons surrounded by a Schwann cell

Located between myelinated segments Nodes exist between each Schwann cell

along myelinated axons Nodes of Ranvier

Regions dominated by myelinated axons Myelin has high fat content which cause

it to look white

Contains unmyelinated axons Makes up a major part of the brain

Remove cell debris, waste, and pathogens by phagocytosis

Resident macrohages of the brain and spinal column

Brain and spinal column considered immune privileged organs because they are seperated by the blood-brain barrier

Clustered in masses called ganglia Satellite cells surround neuron cell

bodies in ganglia Schwann cells form a sheath around

every peripheral axon Schwann cells also enclose segments of

several unmyelinated axons

Oligodendrocyte. (2010). In Encyclopædia Britannica. Retrieved February 03, 2010, from Encyclopædia Britannica Online: http://www.britannica.com/EBchecked/topic/427597/oligodendrocyte

 

Ependymal cell. (2010). In Encyclopædia Britannica. Retrieved February 03, 2010, from Encyclopædia Britannica Online: http://www.britannica.com/EBchecked/topic/189483/ependymal-cell

 

Astrocytes help separate man from mouse. (n.d.). Physorg. Retrieved February 3, 2010, from

Physorg.com website:

http://www.physorg.com/news157036357.html

 

Baumann, N., & Pham-Dinh, D. (n.d.). Biology of Oligodendrocyte and Myelin in the Mammalian Central

Nervous System . In Physiological Reviews. Retrieved February 3, 2010, from American Physiological Society website: http://physrev.physiology.org/cgi/content/full/81/2/871

 

Neuroglia. (n.d.). The Free Dictionary [Dictionary Entry]. Retrieved February 3, 2010, from

http://medical-dictionary.thefreedictionary.com/neuroglia

 

Neuroscience For Kids. (n.d.). Retrieved February 3, 2010, from The Society for Neuroscience website:

http://faculty.washington.edu/chudler/bbb.html

Ion Movement next

The Transmembrane Potential

1. Passive Forces Acting across the Membrane

Chemical Gradients Also known as concentration Gradients Intracellular potassium ion concentration is high

which causes ions to move out of the cell Sodium ions drive ions into the cell Chemical gradients are the forces that cause the

movement in and out of the cells

Electrical Gradients

Potassium ions go through cytoplasm faster than sodium ions do.

This causes a loss in positive charge and makes for an excess in negatively charged proteins

Positive and negative charges are seperated by cell membrane and stops the free movement of ions.

When the positive and negative ions are seperated, potential difference arises

Current

A movement of charges to eliminate a potential difference.

Resistance

A measure of how much the membrane restricts ion movement.

Electrochemical Gradient

Sum of the chemical and electrical forces acting on that ion across the cell membrane.

2.Active Forces across the Membrane

Passive Channels (Leak channels) Always open. Permeability changes as channel changes

shape due to the response of proteins to local conditions.

Ex) Sodium and Potassium leak channels during a cell’s normal resting potential.

2.Active Forces across the Membrane Active Channels

(Gated Channels) Open or Close in Response

to Specific stimuli. Activated

Open Inactivated

Closed Cannot be Opened

Active Channels (Gated Channels)

Chemically Regulated Channels Open or close when specific chemicals

bind to receptor sites.Ex) Binding of ACh at neuromuscular Junctions

Active Channels (Gated Channels)

Voltage Regulated Channels Open or close in response to changes in

transmembrane potential. Found in excitable membranes which can

generate and conduct an action potential.Ex) Voltage regulated sodium, Potassium, and Calcium channels.

Active Channels (Gated Channels)

Mechanically Regulated Channels Open or close upon changes along surface

of membrane.Ex) Sensory receptors that respond to physical stimuli like touch, pressure, and vibration.

Graded Potentials-

Changes in the trans- membrane potential that cannot spread far from the area surrounding site of stimulation.

A. Depolarization

1. The trans-membrane potential is most affected at the site of stimulation and the effect decreases with distance.

2. The effect spreads passively owing to local currents.

3. The graded potential change may involve either depolarization or hyperpolarization. The nature of the change is determined by the properties of the membrane channels involved.

4. The stronger the stimulus, the greater the change in the trans-membrane potential and the larger the area affected.

Any shift from rest potential toward 0mV

B. Repolarization

Chemical stimulus is removed in normal membrane permeability is restored, trans-membrane potential returns to resting

Restoring normal resting potential after depolarization

Combination of ion movement through membrane channels and the activity of ion pumps especially sodium and potassium pumps

C. Hyperpolarization

Rate of potassium outflow increases and the interior of the cell would lose positive ions. Hyper polarization in an increase in the negativity of resting potential.

Action Potentials

Action Potential- The electrical activity developed in a nerve cell during activity.

1. The All-or-None Principle Principle states that if a stimulus is strong

enough to generate a nerve action potential, impulse is conducted along the entire neuron at maximum strength, unless conduction is altered by conditions such as toxic materials in cells or fatigue.

All or None Principle

Action Potentials

2.Generation of Action Potential

1. Depolarization to threshold.(-60mv)

2. Activation of sodium channels and rapid depolarization: Sodium activation gates open and membrane becomes permeable to Na⁺.(-60mv closer to positive)

Action Potentials3. Inactivation of sodium

channels and activation of potassium channels: Voltage regulated channels open. At +30mv, cytosol along the interior of the membrane contains positive charges. K⁺ is moved out of the cell and the loss shifts things back to repolarization.

Action Potentials

4. The voltage-regulated sodium channels return to normal and membrane is now able to generate another action potential. Voltage-regulated potassium pumps begin closing at -70mV. They do not all close at the same time causing potassium to continued to be lost and a temporary hyperpolarization occurs. All voltage-regulated channels close and membrane returns to resting state at end of refractory period.

3.Propagation of Action Potentials

Continuous Propagation Basic mechanism by

which an action potential is propagated along an unmyelinated axon.

Saltatory Propagation The relatively rapid

propagation of an action potential between successive nodes of a myelinated axon.

Propagation of Action Potentials:Continuous Propagation

Propagation of Action Potentials: Saltatory Propagation

Propagation of Action Potentials: Saltatory Propagation

References

All-or-none Principle. (n.d.). Brainwave. Retrieved February 3, 2010, from Brainwave website: http://library.thinkquest.org/ 28457/ allornone.shtml

Martini, F. H. (1999). Neurophysiology. In Neural Tissue. Retrieved February 4, 2010, from Prentice Hall, Inc website: http://cwx.prenhall.com/ bookbind/ pubbooks/ martinidemo/ chapter12/ medialib/ CH12/ html/ ch12_5_2.html

Martini, F. H. (2006). Fundamentals of Anatomy and Physiology (L. Berriman, Ed., 7th ed.). San Francisco, CA: Pearson Education.

Synapse Activity

Synaptic Activity

By: Josh LlanezaMollie Worthington

Logan Michel

Electrical Synapses Type of synapse between 2 apposed neurons Nerve impulse is rapid Occurs by the passage of ions from one neuron

to the other via the gap junction channels Can be bidirectional and unidirectional Used when fast response and coordination of

timing is crucial Escape reflexes Retina of vertebrates Heart rhythm

Chemical Synapses Type of synapse that allows a 2 neurons to

communicate or a neuron to communicate with a non-neuronal cell

1. Action Potential goes down Axon2. Calcium pumps open and Calcium diffuses into Axon3. Synaptic vesicles are forced to synaptic cleft and release

Acetylcholine4. Acetylcholine binds with receptor sites for sodium channel 5. Sodium is diffused into cell, making the membrane

potential more positive6. If the potential reaches threshold level, then an action

potential will be produced

Cholinergic Synapses Cholinergic: Relating to nerve cells or fibers that

employ acetylcholine as their neurotransmitter. Synapses: the site of functional apposition

between neurons, where an impulse is transmitted from one to another, usually by a chemical neurotransmitter released by the axon terminal of the presynaptic neuron.

Cholinergic Synapses: synapses with a chemical neurotransmitter that is made up of acetylcholine.

Acetylcholine: plays an important role both in learning and memory and in sending messages from motor nerves to muscles, especially in the heart, bladder and stomach.

Where Can a Cholinergic Synapses Found? All motor neurons activating skeletal muscle Many neurons of the autonomic nervous system

especially those in the parasympathetic branch Parasympathetic: originating in the brain stem

and the lower part of the spinalcord that stimulate digestive secretions, slow the heart, constrict the pupils, and dilate blood vessels.

Some are found in the central nervous system as well

Other Neurotransmitters Serotonin: normally involved in temperature

regulation, sensory perception, mood control. Plays a major role in emotional disorders such as depression, suicide, impulsive behavior, and aggression.

Norepinephrine: also called noradrenalin; doubles part-time as a hormone. Neurotransmitter = helps to regulate arousal,

dreaming, and moods. Hormone = increases blood pressure, constricts

blood vessels and increases heart rate - responses that occur when we feel stress.

Other Neurotransmitters Cont. Glutamate and GABA (gamma-amino butyric

acid): amino acids that act as neurotransmitters. The majority of synapses within the brain use glutamate or GABA.

They have other functions in the body like making energy-rich molecules in cells.

It is likely that they will be altered during drug addiction. This makes it difficult to treat addiction with

drug therapy without causing side effects.

Bibliography Cell signaling. (2007). Alzheimer society. Retrieved February

4, 2010, from      Alzheimer's Association website: http://alzheimer.ca/english/      alzheimer_brain_mini_site/06.htm

Chemical synapse. (2009). Absolute astronomy. Retrieved February 4, 2010, from      http://www.absoluteastronomy.com/topics/Chemical_synapse

Definition of acetylcholine. (n.d.). Medicine net. Retrieved February 3, 2010,      from MedicineNet, Inc. website: http://www.medterms.com/script/main/      art.asp?articlekey=23278

Electrical synapse. (2009, February 24). Biology online. Retrieved February 3,      2010, from http://www.biology-online.org/dictionary/Electrical_synapse

Bibliography Cont. McKinley, & O'Loughlin. (n.d.). animation chemical synapse [Video].

Retrieved      from Mcgraw hill website: http://highered.mcgraw-hill.com/sites/0072495855/      student_view0/chapter14/animation__chemical_synapse__quiz_1_.html

Millar, N. (2004, June 20). Synapses. In Biology mad. Retrieved February 3,      2010, from http://www.biologymad.com/master.html?http://www.biologymad.com/

     NervousSystem/NervousSystem.htm Other neurotransmitters. (n.d.). Understanding addiction. Retrieved

February 3,      2010, from Addiction Science Research and Education Center, College of      Pharmacy, The University of Texas website: http://www.utexas.edu/research/      asrec/other_p.html

Synapse. (n.d.). The free dictionary. Retrieved February 3, 2010, from Farlex,      Inc. website: http://medical-dictionary.thefreedictionary.com/      cholinergic+synapse

Information Processing next

Information Information Processing by Processing by Individual NeuronsIndividual Neurons

Postsynaptic PotentialsPostsynaptic Potentials

Mike BellMike Bell

Cassie MaysCassie Mays

Gabby SeversGabby Severs

Postsynaptic PotentialsPostsynaptic Potentials

A change in the resting potential of a A change in the resting potential of a postsynaptic cell following the postsynaptic cell following the stimulation from a presynaptic cell.stimulation from a presynaptic cell.

(The change in a signal receiving cell (The change in a signal receiving cell such as a muscle cell after a presynaptic such as a muscle cell after a presynaptic cell such as a motor neuron gives a cell such as a motor neuron gives a neurotransmitter)neurotransmitter)

Yellow- presynaptic Yellow- presynaptic neuronneuron

Green- postsynaptic Green- postsynaptic cellcell

Excitatory Postsynaptic Excitatory Postsynaptic potentials (EPSP)potentials (EPSP) These PSPs increase the likelihood of These PSPs increase the likelihood of

the neural message to be turned into an the neural message to be turned into an action from the postsynaptic cellaction from the postsynaptic cell

They make the membrane of the PS cell They make the membrane of the PS cell more positive (depolarized) and more positive (depolarized) and accelerates the process to get an action accelerates the process to get an action donedone

Inhibitory Postsynaptic Inhibitory Postsynaptic Potentials (IPSP)Potentials (IPSP) Opposite of EPSPOpposite of EPSP An electrical charge in the membrane of a An electrical charge in the membrane of a

postsynaptic neuron caused by the binding of postsynaptic neuron caused by the binding of an inhibitory neurotransmitter from a an inhibitory neurotransmitter from a presynaptic cell to a postsynaptic receptor.presynaptic cell to a postsynaptic receptor.

Makes the cell membrane of the PS cell more Makes the cell membrane of the PS cell more negative (hyperpolarized)negative (hyperpolarized)

Decreases, halts, the action’s chances of Decreases, halts, the action’s chances of being completedbeing completed

•Graph Showing activity in PS cell•EPSP excites•IPSP inhibits

SummationSummation

Temporal summation - Temporal summation - transmission of an impulse by a transmission of an impulse by a rapid stimulation of one or more rapid stimulation of one or more pre-synaptic neurons .pre-synaptic neurons .

Spatial summation - transmission Spatial summation - transmission of an impulse by simultaneous of an impulse by simultaneous stimulation of two or more pre-stimulation of two or more pre-synaptic neurons .synaptic neurons .

The 3 distinct zones 1. Input Zone: the ligand-gated ion channels are activated

by neurotransmitters, or ligands, and secreted by presynaptic terminals. This activation creates a postsynaptic potential.

2. Integrative Zone: summates the postsynaptic potentials and initiates an action potential. Action potential

depends on the activation of voltage-gated ion channels.3. Conductive Zone: then spreads along the action potential.

The postsynaptic potentials require activation of ligand-gated ion channels on the postsynaptic membrane.

FacilitationFacilitation

The amount of neurotransmitter The amount of neurotransmitter released is not always fixed. If the first released is not always fixed. If the first action potential caused more to be action potential caused more to be released by the second, it is called released by the second, it is called facilitation. If less is released, then its facilitation. If less is released, then its considered depression.considered depression.

References References

Burt, A. M. (n.d.). Synaptic Transmission. In Burt, A. M. (n.d.). Synaptic Transmission. In Biology ReferenceBiology Reference. Retrieved February 4, 2010, from . Retrieved February 4, 2010, from http://www.biologyreference.com/ Se-T/ Synaptic-Transmission.htmlhttp://www.biologyreference.com/ Se-T/ Synaptic-Transmission.html

Excitatory and Inhibitory Postsynaptic Potentials. (2001). Excitatory and Inhibitory Postsynaptic Potentials. (2001). Neuro scienceNeuro science. Retrieved February 2, . Retrieved February 2, 2010, from Sinauer Associates, Inc. website: http://www.ncbi.nlm.nih.gov/ bookshelf/ br.fcgi?2010, from Sinauer Associates, Inc. website: http://www.ncbi.nlm.nih.gov/ bookshelf/ br.fcgi?book=neurosci&part=A477book=neurosci&part=A477

Giuliodori, M. J., & Zuccolilli, G. (2004). Postsynaptic Potential Summation and Action Potential Giuliodori, M. J., & Zuccolilli, G. (2004). Postsynaptic Potential Summation and Action Potential Initiation. In Initiation. In Advances in Physiology EducationAdvances in Physiology Education. Retrieved February 4, 2010, from . Retrieved February 4, 2010, from http://advan.physiology.org/ cgi/ content/ full/ 28/ 2/ 79http://advan.physiology.org/ cgi/ content/ full/ 28/ 2/ 79

Postsynaptic Potential. (2008, March 11). Postsynaptic Potential. (2008, March 11). MondofactoMondofacto [Online Medical Dictionary]. Retrieved from [Online Medical Dictionary]. Retrieved from http://www.mondofacto.com/ facts/ dictionary?postsynaptic+potentialhttp://www.mondofacto.com/ facts/ dictionary?postsynaptic+potential

Postsynaptic Potentials. (n.d.). Postsynaptic Potentials. (n.d.). Washington UniversityWashington University. Retrieved February 2, 2010, from . Retrieved February 2, 2010, from http://courses.washington.edu/ conj/ neuron/ postsynaptic.htmhttp://courses.washington.edu/ conj/ neuron/ postsynaptic.htm

Diseases The words are there. Click in the white

space and they will appear. Don’t ask me why!! Has to do with the formatting. You can always go to 2nd or 3rd.

What Is Parkinson's Disease?

Parkinson's disease is a brain disorder that leads to several symptoms that effect the body such as; shaking, stiffness, and difficulty with walking, balance, and coordination. It affects about half a million people in the United States. The average age of onset is 60 years, and the risk of developing Parkinson's goes up with age.

What Causes Parkinson's Disease?

Parkinson's disease occurs when nerve cells, or neurons, in an area of the brain that controls movement die. Normally, these neurons produce an important brain chemical known as dopamine, but when the neurons are affected or die off the less dopamine is made. This shortage of dopamine causes the movement problems for the people affected by this disease.Dopamine is a chemical messenger, or neurotransmitter. Dopamine is responsible for transmitting signals for multiple spots in the brain. The connection is critical to produce smooth, movement.

•Treatment and ResearchAlthough there is no cure for Parkinson's disease, medicines and surgery can often provide help with dealing with it. However, these treatments are not very effected sometimes and scientist are trying to find better ways to treat it. Recent advances in areas such as genetics, drug therapy, and brain stimulation offer hope that some day it may be possible to cure the disease, delay its onset, or prevent it altogether.•Medications“Medications for Parkinson's fall into three groups. The first group includes drugs that increase the level of dopamine in the brain. The second group affects other neurotransmitters in the body in order to ease some of the symptoms of the disease. The third group includes medications that help control non-motor symptoms (those that do not affect movement) of Parkinson's.”•“Surgical Treatments and Other TherapiesPallidotomy was once the most common surgery for Parkinson's. In this procedure, a surgeon destroys a portion of the brain called the globus pallidus. Pallidotomy can improve symptoms of tremor, rigidity, and bradykinesia, possibly by interrupting the connections between the globus pallidus and the striatum or thalamus.”http://www.buzzle.com/articles/mercury-poisoning-symptoms.htmlhttp://nihseniorhealth.gov/parkinsonsdisease/faq/faq1a.html

Mercury is odorless, colorless, and tasteless. Only liquid metal at room temp. Very toxic. Used in Thermometers, Barometers, Batteries, and

Vapor-Lamps. Found as a native metal. Found within cinnabar, corderoite & livingstonite. Roughly 50% of our supply comes from Spain & Italy.

Mercury breaks the barrier between blood, and the brain.

Mercury binds to organelles in cells, such as mitochondria, endoplasmic reticulum, Golgi complex, nuclear envelopes and lysosomes.

Although very little mercury binds to the nucleus, there is severe decrease of neuronal RNA and protein synthesis.

Disrupted enzymatic systems in the glycolytic pathway in the brain.

There are also irregular excitation spikes in mercury-intoxicated neurons.

Sensory neurons in the spinal ganglia and granule cells in the cerebellum are the most vulnerable to mercury poisoning.

Causes headaches, vertigo, tinnitus, shaking in various areas of the body.

Angry fits, short term memory loss, low self esteem, inability to sleep, loss of self-control, sleepiness, and difficulty learning.

Mercury degenerates nerve fibers.

TREATMENTS OF T.S.D ?

Currently, there is no cure or effective treatment for Tay-Sachs.

is a rare inherited disorder that destroys nerve cells (neurons) in the brain and spinal cord.

Fatty substances called ganglioside (GM2) build up in tissues and nerve cells in the brain.

This rare

inherited disorder

disease usually

happens to

babies.

 as nerve cells become distended with fatty material, a relentless deterioration of mental and physical abilities occurs.

The child becomes blind, deaf, and unable to swallow. Muscles begin to atrophy and paralysis sets in. Other neurological symptoms include dementia, seizures, and an increased startle reflex to noise. 

WHAT IS MULTIPLE SCLEROSIS?

Is an autoimmune diseasethat affects the brain and

spinal cord(central nervous

system), and asa result loss of certain body

function and physical abilities.

HOW DOES M.S AFFECT THE CENTRAL NERVOUSE SYSTEM ?

 It damages the myelin sheath, the material that surrounds and protects your nerve cells.

M.S MAKE A PERSON HAVE:

Visual disturbances Muscle weakness Trouble with coordination and balance Thinking and memory problems And since it affects your spinal cord you

can be paralyzed.

TREATMENTS OF M.S?

At this time there is no cure for M.S. The goal is to use medication which will

slow the progression of multiple sclerosis which are: (Avonex, Betaseron, or Rebif), monoclonal antibodies(Tysabri), glatiramer acetate (Copaxone),

Sources (to be cited)

Picture of Mercury. [Data file]. (n.d.). Retrieved from http://www.periodictable.com/Samples/080.14/ s13.JPG

W, C. L. (1977). Neurotoxic effects of mercury: a review. Unpublished raw data, Univ. of Arkansas Medical School, Little Rock. Retrieved from Energy Citations Database.

Facts about Mercury [Fact list]. (n.d.). Retrieved from facts-about website: http://www.facts-about.org.uk/science-element-mercury.htm

Pakhare, J. (2007, May 5). Mercury Poisoning Symptoms [Facts]. Retrieved from Buzzle website: http://www.buzzle.com/articles/mercury-poisoning-symptoms.html

http://nihseniorhealth.gov/parkinsonsdisease/faq/faq1a.html