Neuron Notes New

8/12/2019 Neuron Notes New

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It all Starts with the Neuron

http://videos.howstuffworks.com/health/human-brain-videos-playlist.htm#video-6080

http://videos.howstuffworks.com/health/human-brain-videos-playlist.htm















Neuron Structure

Neurons do NOT touch each other- the space in

between is called synaptic cleft.



Neural Bases of Psychology:

The Structure of a Neuron



How a Neuron Fires

It is an electrochemical process

„ Electrical inside the neuron

„ Chemical outside the neuron (in the

synapse in the form of aneurotransmitter).

„ The firing is call Action Potential.




Neural Communication

• Within a neuron, communication occurs

through an action potential (neural

impulse that carries information along theaxon of a neuron).




Neural Communication

• Within a neuron, communication occurs

through an action potential (neural

impulse that carries information along theaxon of a neuron).



The All-or None Response

• The idea thateither the

neuron fires orit does not- nopart way firing.

• Like a gun



Steps of Action Potential• Dendrites receive neurotransmitter from another

neuron across the synapse.

• Reached its threshold - then fires based on theall-or-none response.

• Opens up a portal in axon, and lets in positive ions(Sodium) which mix with negative ions (Potassium)

that is already inside the axon (thus Neurons atrest have a slightly negative charge).• The mixing of + and – ions causes an electrical

charge that opens up the next portal (letting inmore K) while closing the original portal.

• Process continues down axon to the axonterminal.

• Terminal buttons turns electrical charge intochemical (neurotransmitter) and shoots message

to next neuron across the synapse.



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Action Potential



How Neurons Communicate





• Which sentence most closely describes

neural transmissions?

• A. an electric charge is created in the neuron, the

charge travels down the cell, and chemicals are

released that cross the synapse to the next cell

• B. a chemical change occurs within the cell, the

change causes an electric charge to be produced andthe charge jumps the gap between the nerve cells.

• C. the electric charge produced chemically inside a

group of neurons causes chemical changes in

surrounding cells

• D. neurotransmitters produced in the hindbrain are

transmitted to the forebrain, causing electric



Neurotransmitters

„ Chemical messengers released by

terminal buttons through the synapse.

„ We should know at least 6 types andwhat they do.



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Neurotransmitters



Acetylcholine„ Its function is motor movement and

maybe memory.

To much and you will….

Not enough and you will….

Lack of ACH has been linked to

Alzheimer’s disease.



Dopamine„ Its function is motor movement and

alertness.

Lack of dopamine is

associated with

Parkinson’s disease.

Overabundance is

associated with

schizophrenia.



PET scan

• Parkinsons

– Muscle rigidity

–

Tremors – Speech slur

– Difficult gait

• Before/After medicine

www. Epub.orgWhat type of scan

Is this?



Serotonin

„ Function deals with mood control.

Lack of serotonin has

been linked to

depression.



Endorphins

• Function deals with paincontrol.

We become addictedto endorphin causing

feelings.



What are agonists and

antagonists?

• They are drugs

• Agonists mimic neurotransmitters.

Example: Nicotine is an ACh agonist

• Antagonists block neurotransmitters:

•

Ex: curare is an antagonist for ACh(paralyzes you)



Agonists and Antagonists



• You eat some bad Chinese food and

feel you are losing control of your

muscles. The bacteria you ingestedfrom the food most likely interferes with

the use of:

• A. serotonin• B. insulin

• C. acetylcholine

• D. Thorazine

• E. adrenaline



What is reuptake?

• The mopping up of excess

neurotransmitter.

oExcessneurotransmitters in thesynapse are reabsorbed

into the sendingneurons.

•This process appliesthe brakes on

neurotransmitter action.



How does Prozac work?

• It is a serotonin reuptake inhibitor.



How does Cocaine work?

The white cocaine blocks the reuptake of dopamine.



Types of eurons

Sensory NeuronsMotor Neurons

Inter Neurons

Ki d f N



28

Kinds of Neurons http://videos.howstuffworks.com/health/human-brain-

videos-playlist.htm#video-6081

•Motor Neurons carry outgoing information from the

CNS to muscles and glands.•Interneurons connect the two neurons.

•Sensory Neurons carry incoming information fromthe sense receptors to the CNS.

Sensory Neuron(Bipolar)

Interneuron Neuron(Unipolar)

Motor Neuron(Multipolar)














Divisions of the Nervous System

“para” like

A parachute



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Peripheral Nervous System

Somatic Nervous System:

• Controls voluntary musclemovement.

• Uses motor (efferent) neurons.

Autonomic Nervous System: • Controls the automatic functions

of the body.

• The glands and muscles• Divided into two categories…thesympathetic and theparasympathetic



31

Autonomic Nervous System (ANS)

• Sympathetic Nervous System:

• Fight or Flight Response during stressfulsituations.

• Automatically accelerates heart rate,

breathing, dilates pupils, slows downdigestion.

Parasympathetic Nervous System:

• calms the body, conserving its energy.

•Provides homeostasis homeo = same

Homeostasis means same state you were in

before you saw the dog!



Think how the right

side is different from

the left side.

Lie detector

http://videos.howstuff

works.com/discovery

/6833-human-body-

how-polygraph-tests-

work-video.htm

http://videos.howstuffworks.com/discovery/6833-human-body-how-polygraph-tests-work-video.htm
























A Simple Reflex





Mouse lab

• http://learn.genetics.utah.edu/content/addi

ction/drugs/mouse.html

35

http://learn.genetics.utah.edu/content/addiction/drugs/mouse.html




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