Vocabulary From Chapters 4-5

Front 1

What are the 3 steps in which neurons communicate at synapses?

Back 1

Electrical - Chemical - Electrical

Front 2

What is the action potential?

Back 2

An electrical impulse that travels down the axon to the axon terminal.

Front 3

What are mitochondria?

Back 3

"Power packs" found in the cell body and axon terminal.

Front 4

What are synaptic vesicles?

Back 4

Tiny sacks that store neurotransmitters. The electical impulse ruptures the synaptic vesicles and their neurotransmitters spill out into the synaptic gap seperating the neurons.

Front 5

What is a synaptic gap?

Back 5

A tiny fluid-filled space between the axon terminal of the neuron sending the message and the dendrite of a receiving neuron.

Front 6

Pre-synaptic neuron

Back 6

The sending neuron

Front 7

Post-synaptic neuron

Back 7

The receiving neuron

Front 8

What is the neurotransmitter - receptor relationship?

Back 8

Neurotransmitters and receptors have a "lock and key" relationship. They can only bind with it's matching counterpart.

Front 9

What are ions?

Back 9

Electrically charged particles found in the fluid filled extracellular spaces between neurons and the interior of the cell. (sodium and chloride)

Front 10

What is a polarized neuron?

Back 10

A non-firing "resting state" neuron. It's interior has a negative charge while the fluid filled spaces surronding have a positive charge.

Front 11

What are ion gates or channels?

Back 11

Regulates the flow of ions into the post-synaptic neuron. On the surface of the neuron. Polarized = closed. Receptors open the gates.

Front 12

What is a depolarized neuron?

Back 12

As ion gates are opened and ions flow through the neuron the neuron becomes positive.

Front 13

What is the firing threshold?

Back 13

When the influx of positive ions reach a critical threshold, a new electrical impulse travles down the axon. This leads to a new message being transmitted to other neurons.

Front 14

What is hyperpolarization?

Back 14

Inhibitory neurotransmitters bind with receptors of a firing neuron to allow influx of negatively charged ions in to stop neuron from firing.

Front 15

What is tetrodotoxin?

Back 15

TTX is one of the most potent toxins known to science. TTX prevents firing of the cell.

Front 16

What are excitatory signals?

Back 16

Cause the neuron to fire and action potential down its axon.

Front 17

What are inhibitory signals?

Back 17

Opposite

Front 18

What is inactivation?

Back 18

When a neurotransmitter has completed its work its released by the receptor back into the fluid filled synapse.

Front 19

What is diffusion?

Back 19

The neurotransmitter drifts away, out of the synaptic cleft where it can no longer act on a receptor.

Front 20

How do glial cells help inactivate?

Back 20

Astrocytes mop-up the neurotransmitters from the synaptic gap.

Front 21

What is re-uptake?

Back 21

The neuron's recycling system. The neurotransmitter is transported back into the axon terminal of the pre-synaptic neuron. The neurotransmitter is then 1)repacked back into the synaptic vesicles 2)degraded by enzymes into parts for future use 3) used to make new neurotransmitter molecules

Front 22

What is enzymatic degradation?

Back 22

Special enzymes degrade the structure of the neurotransmitter so it's not recognized by the receptor.

Front 23

What criteria must chemicals meet to be considered a neurotransmitter?

Back 23

1) The chemical must be made in a neuron
2)The chmecial must be found in a neuron
3) When stimulated the neuron releases the chemical
4)When released, the chemical must act on the receptor of a post-synaptic neuron and produce a biological response in the receiving neuron.
5)The same response should occur when the chemical is experimentally applied to the membrane of the post-synaptic neuron.
6)After a chemical is released it must be inactivated.

Front 24

What are the three classification groups of neurotransmitters?

Back 24

1)Small-molecule neurotransmitters
2)Neuropeptides
3)Transmitter gasses

Front 25

What is synaptic transmission?

Back 25

A variety of ways in which receptors and neurotransmitters interact.

Front 26

What are the variety of ways in which receptors and neurotransmitters interact?

Back 26

1)Each neuron may release and respond to several different neurotransmitters.
2)Each neurotransmitter may have several different types of receptors it can bind with.
3)Neurotransmitters can be excitatory or inhibitory.
4)Some neurotransmitters transmit rapidly and others slower.

Front 27

What are precursor molecules?

Back 27

Substances found in our digestive tract that are transported via bloodstream to the brain. Are made into neurotransmitters.

Front 28

What is the process of synthesizing neurotransmitters?

Back 28

Precursor molecules from digestive tract to bloodstream -> Precursors transported into brain ->Enzymes in neuron converts precursors into neurotransmitters -> Neurotransmitter packaged into synaptic vesicles in axon terminal.

Front 29

What is GABA's precursor and where is it found?

Back 29

Glutamic acid/Avocado and meat

Front 30

What is Serotonin's precursor and what is it found in?

Back 30

Tryptophan / Turkey and fish.

Front 31

What is acetylcholine? (Ach)

Back 31

Plays a key role in memory and cognitive functioning and is the primary neurontransmitter used in all muscular movement. It plays a role in triggering REM.

Front 32

What is Serotonin?

Back 32

Also known as 5-ht, one the most important neurotransmitters. It is the police of the brain it keeps our impulses thoughts moods and emotions under control. Plays roles in sleep and pain.

Front 33

How is Serotonin synthesized?

Back 33

Typtophan -> Serotonin -> Melatonin

Front 34

What is dopamine?

Back 34

Involved in a variety of important functions including: movement, attention, learning, perception, cognition, motivation, pleasure and the reinforcing effects of certain drugs.

Front 35

What happens if there is low dopamine activity?

Back 35

Depression, increased need for sleep, substance dependency

Front 36

What happens if there is excess dopamine activity?

Back 36

Anxiety and fear, agression and delusions.

Front 37

What is the catecholamine family?

Back 37

Dopamine, norepinephrine and epinephrine.

Tyrosine -> L-Dopa -> Dopamine -> Norepinephrine -> Epinephrine

Front 38

What is norepinephrine?

Back 38

It is derived from dopamine, it is the "Pay Attention/Alertness" chemical. It is synthesized by a small cluster of neurons in the brain stem.

Front 39

What is GABA?

Back 39

It is the most important inhibitory neurotransmitter in the CNS and is used by 40% of the brain's synapses. "Valium of the brain"

Front 40

What is Glycine?

Back 40

It is another major inhibitory neurotransmitter, low levels of this chemical cause muscles to contract and spasm.

Front 41

What is glutamate?

Back 41

Is the primary excitatory neurotransmitter of the CNS. Produced by large cells throughout the brain stem. Increases altertness, attention, arousal and memory.

Front 42

What is a seizure?

Back 42

An electric storm occurring in the brain. Triggers: lack of sleep, stress, hormonal changes of the menstrual cycle, flashing lights etc.

Front 43

What are neuropeptides?

Back 43

Chemical compounds made up of short chains of amino acids produced both in brain and body. They can work as neuromodulators, hormones or neurotransmitters.

Front 44

What are enogenous opiods?

Back 44

Neuropeptides that produce their effects by binding to the same receptors stimulated by opiate drugs. They regulate pain, emotions, stress etc.

Front 45

What is the nocebo effect?

Back 45

Occurs when a patient's negative beliefs about medical treatment produce negative health effects.

Front 46

What are the most important love chemicals?

Back 46

Serotonin, dopamine, norepinephrine and the neuropeptides vasopressin, phenylthlamine (PEA) and oxytocin.

Front 47

What is phenylethylamine?

Back 47

One of the primary chemcials of infatuation, lust and romantic love. After the chemicals effects either we develop true love or move on. Found in chocolate.

Front 48

What is oxytocin?

Back 48

The cuddle chemical or true love chemical. Plays a major role in promoting bonding. Increases skin sensitivity, promotes the flow of breast milk.

Front 49

What are gaseous neurotransmitters?

Back 49

They aren't stored in synaptic vesicles but instead diffuse through the neuron and act upon receptors within the neuron.

Front 50

What are two examples of gaseous neurotransmitters?

Back 50

Nitric Oxide and Carbon Monoxide. NO is also called laughing gas, invovled in memory formation and digestion. CO helps produce the classical neurotransmitters.