It all Starts with the Neuron

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

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 FiresIt is an electrochemical process•Electrical inside the neuron•Chemical outside the neuron

(in the synapse in the form of a neurotransmitter).

•The firing is call Action Potential.

Neural Bases of Psychology: Neural Communication

• Within a neuron, communication occurs through an action potential (neural impulse that carries information along the axon of a neuron).

Neural Bases of Psychology: Neural Communication

• Within a neuron, communication occurs through an action potential (neural impulse that carries information along the axon of a neuron).

The All-or None Response

• The idea that either the neuron fires or it does not- no part 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 the

all-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 at rest have a slightly negative charge).

• The mixing of + and – ions causes an electrical charge that opens up the next portal (letting in more K) while closing the original portal.

• Process continues down axon to the axon terminal.

• Terminal buttons turns electrical charge into chemical (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 and the 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 and what 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 medicinewww. Epub.org What type of scan

Is this?

Serotonin•Function deals with mood control.

Lack of serotonin has been linked to depression.

Endorphins•Function deals with pain

control.

We become addicted to 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 ingested from 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.

oExcess neurotransmitters in the synapse are reabsorbed into the sending neurons.•This process applies the 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 Neurons

Sensory NeuronsMotor NeuronsInter Neurons

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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 from the sense receptors to the CNS.

Sensory Neuron(Bipolar)

Interneuron Neuron (Unipolar)

Motor Neuron(Multipolar)

Divisions of the Nervous System

“para” likeA parachute

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Peripheral Nervous SystemSomatic Nervous System: •Controls voluntary muscle movement.•Uses motor (efferent) neurons.Autonomic Nervous System: •Controls the automatic functions of the body.•The glands and muscles•Divided into two categories…the sympathetic and the parasympathetic

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Autonomic Nervous System (ANS)• Sympathetic Nervous System: • Fight or Flight Response during stressful situations.• Automatically accelerates heart rate, breathing, dilates

pupils, slows down digestion.

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 rightside is different fromthe left side.

Lie detector 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/addiction/drugs/mouse.html

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