AP Psych- Neural Communication

In the early 1800's Franz Gall introduced phrenology. Theory claimed that bumps on the skull revealed mental abilities and traits.

Axon= messages pass to other neurons, muscles or glands; exiting through terminal buttons

Axon's surface is selectively permeable,

picky about what it let's in!

Acting like a key, the neurotransmitter unlocks

small channels of receiving site allowing ions to enter

receiving neuron

http://learn.genetics.utah.edu/content/addiction/reward/neurontalk.html

Make sure to read about other transmitters

(Glutamate, GABA, etc...)

Agonists vs. Antagonists

agonists and antagonists act on the neurotransmitters

Agonists= any substance that mimics or has a similar effect to a neurotransmitter (excite;

transmitter, drugs, hormone)

Phrenology

Antagonists= any substance that inhibits the

effect of a neurotransmitter (inhibit; drugs, poisons)

Types of

Neurotransmitters

ACh (acetycholine)= enables muscle action, learning and memory

* lack of ACh associated with Alzheimer's

Dopamine= movement, learning, attention and emotion

* lack of can lead to Parkinson's

* excess associated with schizophrenia

Serotonin= mood, hunger, sleep, arousal

* lack of can lead to depression

Parts of Neuron

Dendrite= bushy fibers that receive information

Reuptake= when excess neurotransmitters are reabsorbed by sending neuron

"AXONS SPEAK. DENDRITES LISTEN."

Myelin sheath= insulates axons; helps speed up impulses

Neurons

Neurons process and transmit information throughout our body.

Neuroscience

and

Behavior

Neurotransmitters

The Chemical Messengers

The Basic Components

of a Synapse

Myelin Sheath and MULTIPLE SCLEROSIS

Excitatory neurotransmitters=

bring the dendrite closer to threshold by allowing positive ions to rush in.

* increase in positive charge in cell = excitatory!

more likely to fire action potential

Inhibitory neurotransmitters=

take the dendrite further away from threshold by allowing negative ions to rush in

* decrease in positive charge=more negative= inhibitory!

Evidence shows that people who suffer from multiple sclerosis do not have adequate insulation from the myelin sheath. As the sheath degenerates, the communication between neurons, muscles and glands slows. Can lead to sensory impairments, coordination difficulties and control of bodily functions.

synapse= the junction between axon end of sending neuron and dendrite or cell body of receiving neuron

synaptic gap/cleft= space between sending and receiving neuron

neurotransmitters= chemical messengers; released by sending neuron, travels across synapse and bind to receptor sites of receiving neuron (stored in vesicles)

How are messages transmitted?

Along the neuron= electrical; this is called an action potential

First Things First

ACTION POTENTIAL

So you may ask...

What happens when the action potential reaches the axon terminal?

A neural, ELECTRICALLY CHARGED impulse that travels down the axon.

Between two neurons= chemical; this is called synaptic transmission

* fluid interior of a resting axon has negatively charged ions

* fluid outside axon membrane has positively charged ions

= Resting potential

Chemical; SYNAPTIC TRANSMISSION

Neural Communication Checklist

Action Potential is Dependent Upon...

Action Potential Continued

Depolarization= neuron fires from stimulation, gates open, positively charged sodium ions rush in

causes domino effect, further action potential along the axon

Resting Potential

* Charge

*Ions

Change in Charge

*Neurotransmitters

*Ions

*Failed attempt

*Reaching threshold (all-or-none)

threshold= level of stimulation required to trigger neural impulse

Refractory period= neuron pumps positive ions back out

a net flow of sodium ions into the cell causes rapid change in potential across the membrane

Neural Communication Checklist

Action Potential

*Firing

*Ions

*Myelin

*Depolarization

Refractory Period

* Sodium gates close, potassium pumped out

*negative charge restored

* back to resting potential

Neurons either fire or they don't;

it is an all-or-none response!