Warm-up!

You enter a small room.

The door closes.

The door opens, and you’re in a different place.

Where are you?

Nerves!

Nerves send signals from the skin to the brain to process sensory information.

The brain sends signals along nerves to the muscles to produce movements.

But how does this happen???

Nerves don’t even touch!

Neurons do not physically touch one another where they connect, so how do they send messages?

Nerves send messages when an electrical signal passes down the axon.

At the end of the axon is a Synapse, which is where it meets with the dendrite or the cell body of another neuron (target cell).

The electrical signal triggers the release of chemical signals through the synapse to the target cell.

Those chemical signals are………..

Neurotransmitters!

What is a neurotransmitter?

A chemical produced by a neuron that causes a reaction in a target neuron.

May excite or turn on a neuron

May inhibit or prevent the neuron from turning on

May cause a series of reactions called a “cascade”

How do neurotransmitters work? Neurons create and store neurotransmitters until they

are needed.

Neurons are stimulated by creation of an electrical charge.

This electrical charge causes the neurotransmitters to be released into the synapse of the axon.

The neurotransmitters bind to special receptors on the target cell to cause a specific response.

What types of response? Excitement of a target cell

Responsible for motivation, boosting energy, and increased alertness

Inhibitory Responsible for mood stabilization, sleep cycle, appetite

control, and blood pressure regulation.

Cascade reactions Series of reactions where there is a series of stimulations

along a pathway of neurons.

Frequently seen in drug use, addictions, and near-death experiences.

Types of neurotransmitters Acetylcholine

Motor control, learning, memory, sleep, dreams

Serotonin

Emotion, impulses, dreams

Norepinephrine

Alertness, vigilance, fear reaction

Epinephrine

Energy boost

Types of neurotransmitters Dopamine

Rewards, motivations, motor control

Frequently associated with addictions

Melatonin

Sleep cycle regulation

Endorphins

Rewards, pain reduction

Glutamate

Regulates learning and memory

Types of neurotransmitters GABA

Slows excitation of cells

When neurons get overstimulated, GABA calms them

Oxytocin

“love hormone”

Increases trust, bonding, and feelings of love in women

Vasopressin

Regulates blood pressure

Increases paternal feelings, social interaction, and trust and bonding reactions in men

What if something goes wrong?If neurotransmitter levels get out of balance, many things can happen within the body.

Imbalances of acetylcholine can cause twitching and paralysis

Imbalances of serotonin can cause aggression and depression

Imbalances of dopamine are related to Parkinson’s disease

What can cause imbalances? There are many things that naturally occur or can

happen that will cause imbalances of neurotransmitters within the body

Heredity

Injury

Drug abuse

Stress

Poor diet

Hormone imbalance

Lack of sleep

Tomorrow….

We will discuss the effects of various drugs on the brain and how they influence the balance of neurotransmitters within the body.