the neurons

7/29/2019 the neurons

1/31

111

How is the Nervous SystemOrganized?

Chapter 3-Neuroscience:The Brain and Behavior


2/31

2

Class Objectives:

Identify and define the structures ofthe neuron

Identify and discuss the role ofneurotransmitters on behavior


3/31

3

The Neuron

The neuron is the basic buildingblock of the nervous system

They are often grouped in bundlescallednerves.


4/31

4


5/31

5


6/31

6

4 parts of the neuron

1. Dendrites are specialized to receive signalsfrom neighboring neurons and carrythem back to the cell body

Thin, bushy-like structures that receiveinformation from outside the neuron

Relays the information into the cell body


7/31

7

The Neuron

2. The Cell bodycontains thecell nucleus

The cell bodyrelays the

informationdown to theaxon


8/31

8

The structure of a neuron

3. Axon: A thin, long structure that

transmits signals from the cell body tothe axon terminal.

4. Axon Terminal is the last step for the relayof information inside the neuron.


9/31

9

The cellbody is

coveredwith AxonTerminals


10/31

101010

Once the information hits theterminal, it is transmitted

outside the cell byneurotransmitters, which reside

in the axon terminal.


11/31

111111

-Electrical Communication-Chemical Communication

How do NeuronsCommunicate?


12/31

12


13/31

13

The Electrical Part

Action potential is an electrical current

sent down the axon.

The activity within the neurons is

electrical. This current causes theneuron to fire

This is an all-or-none process


14/31

14

Action potentials travel down the axon likea wave of energy


15/31

15

Synaptic transmission

The Synapse is the space between neurons

The synaptic gap or cleft

Information must be transmitted acrossthe synapse to other neurons via theneurotransmitters.

This is an electrochemical process


16/31

16

Lets Review!


17/31

171717

Now, Lets DANCE!

Time to do the Neuron Dance


18/31

18

Presynaptic Neuron

________________________

__________

________

________

____________


19/31

19

Neurotransmitters

Neurotransmitters are chemicalsubstances that reside in the axonterminals

They communicate to other neurons bybinding to receptors on neighboringneurons

h


20/31

20

Chemical Communication

The communication between neurons ischemical

Neurotransmitter are either neutralizedby an enzyme or taken back up by theneuron that released it in reuptake.

At least 50 different types ofneurotransmitters have been identified


21/31

21

Chemical Communication


22/31

22

Synaptic Transmission

The neurotransmitters are released fromthe vesicles and then attach to receptorslocated on the postsynaptic neuron.

These neurotransmitters are in contactwith the dendrite of the postsynapticneuron only briefly.

The chemical is almost immediatelydestroyed or reabsorbed


23/31

23

Neurotransmitters

At least 50 different types ofneurotransmitters have been identified

Acetylcholine GABA

Serotonin

Dopamine

Norepinephrine

Endorphins

A l h l


24/31

24

Acetylcholine

Activates motor neurons controllingskeletal muscles

Contributes to the regulation of attentionarousal and memory

l f


25/31

25

Examples of Neurotransmitters

Gamma-aminobutyric acid (GABA) isinvolved in experiences of anxiety,alcohol abuse, seizure disorders, andsleep disorders

Serotonin is involved in sleep andmood regulation and appetite (appetitefor carbohydrates)

D i


26/31

26

Dopamine

Involved in movement, thoughtprocesses, emotion, feelings of rewardand pleasure

Implicated in schizophrenia, attentiondeficit disorder, and drug abuse

N i h i


27/31

27

Norepinephrine

Involved in arousal reactions (increasingheart rate, respiration, sweating, anddilation of pupils)

May also be involved in hunger, eating,and sexual activity


28/31

282828

How do drugs effect

behavior?


29/31

29

Drugs Impact on the Brain

Common drugs can alter the amount of aneurotransmitter released at the synapses

Some drugs can mimic/facilitate the action ofthe neurotransmitters while others can blockthe action of the neurotransmitter.

A i A i


30/31

30

Agonists versus Antagonists

Agonists mimic or facilitate the actions of a

neurotransmitter

Antagonists oppose/block the actions of aneurotransmitter

AntagonistAgonist


31/31

31

Next Class

The Brain

How do the neurons work together?

The Central Nervous System

The Peripheral Nervous System

the neurons

Documents

Transcript of the neurons