Week Four

Question 1

What are the stages of synaptic transmission?

Answer 1

1. Action potential reaches the axon terminal of the presynaptic neuron
2. Depolarization of the terminal leads to an influx of Calcium
3. The vesicles bind to the membrane of the axon terminal
4. Vesicles release neurotransmitters into the synaptic cleft
5. Neurotransmitters bind to receptors causing either excitatory postsynaptic action potentials (EPSP) or inhibitory postsynaptic actions potentials (IPSP)
6. Excess neurotransmitters are removed from the synapse through breakdown or reuptake into the presynaptic cell
7. Other Neurotransmitters in the synapse bind to autoreceptors in the presynaptic membrane to give “feedback” on the signal that it produced

Question 2

What are ligands?

Answer 2

Molecules that bind to postsynaptic receptors and can either “activate” or “deactivate” them

Question 3

What are endogenous ligands?

Answer 3

Ligands which are made within the body such as neurotransmitters

Question 4

What are exogenous ligands?

Answer 4

Ligands which are made outside of the body such as drugs

Question 5

What are the two types of receptors in the post-synaptic membrane.

Answer 5

Ionotropic receptors & Metabotropic receptors

Question 6

What are Ionotropic receptors and how do they work?

Answer 6

Ionotropic receptors are receptors which have ion channels. When a neurotransmitter binds to them, their channels open to allow for the flow of ions into the membrane, but only for a few seconds.

Question 7

What are Metabotropic receptors and how do they work?

Answer 7

Metabotropic receptors are receptors that do not have their own ion channels. When a neurotransmitter binds to a metabotropic receptor, which in turn activates G-proteins which act as second messengers which open other ion channels for a longer period of time.

Question 8

What are the three different types of effects that ligands can have on receptors?

Answer 8

1. Agonists: which activate/opens channels
2. Antagonists: which deactivate and hold the channels closed (inserts the key but just blocks the lock)
3. Inverse Agonists: will bind and make the receptor to the opposite of it’s reaction

Question 9

What is Glutamate?

Answer 9

It is the primary excitatory neurotransmitter found in the brain.

Question 10

What is GABA?

Answer 10

It is the primary inhibitory neurotransmitter found in the brain.

Question 11

Where is Acetylcholine distributed, source, and function?

Answer 11

Acetylcholine is widely distributed throughout the PNS and CNS. Acetylcholine’s source is the forebrain nuclei, and Acytlcholine’s functions include alertness and signal amplification.

Question 12

Where is serotonin distributed, source, and function?

Answer 12

Serotonin is a hormone and neurotransmitter which is broadly distributed in the CNS. Serotonin’s source is the Raphe Nuclei. Serotonin functions in mood, and cognition.

Question 13

Where is Norepinephrine distributed, source and function?

Answer 13

Norepinephrine is a hormone and a neurotransmitter which coordinates with the autonomic nervous system. It’s source is the locus coeruleus. Norepinephrine functions in general cognition.

Question 14

Where is Dopamine distributed, source and function?

Answer 14

Dopamine is a hormone and neurotransmitter and has several forebrain pathways. It’s source is the ventral tegmental area. Dopamine functions in motor regulation and reinforcement.

Question 15

What are five ways in which drugs can affect the pre-synaptic cell?

Answer 15

1. Inhibition of transmitter synthesis, not allowing certain transmitters to synthesize
2. Blockade of Axonal Transport
3. Prevention of synaptic activity (not allowing for the firing of action potentials)
4. Inactivation of transmitter reuptake
5. Blockade of transmitter degradation

Question 16

What are five ways in which drugs can affect the post-synaptic cell?

Answer 16

1. Blockade of receptors
2. Activation of receptors
3. Modulation of intracellular signals, alternation of second messenger systems
4. Down-regulation of receptors, decrease in post-synaptic receptor density
5. Up-regulation of receptors, increase in post-synaptic receptor density

Question 17

What is down-regulation?

Answer 17

Down-regulation is a long-term effect that ligands can have on receptors. It causes a decrease in receptor density, making the synapse weaker as there is less weight.

Question 18

What is up-regulation?

Answer 18

Up-regulation is a long-term effect that the ligands can have on receptors. It causes an increase in receptor density, making the synapse strong as it has more weight .

Question 19

What are the five stages of drug action?

Answer 19

1. Administered
2. Absorbed
3. Binds to a receptor or a depot
4. Breakdown-Inactivation
5. Elimination from the body

Question 20

What are the 3 factors which influence the effect of the drug on the body?

Answer 20

1. Dose
2. Set (individual variables)
3. Setting (Situation variables)

Question 21

What are five types of psychoactive drugs and a brief description of the mechanism of action on the brain?

Answer 21

1. Anxiolytics: Calm the sytem, GABA agonists, increase inhibition
2. Cannabinoids: affect hunger, memory, and stress, bind to cannabinoid receptors
3. Ethyl Alcohol: CNS depressant
4. Opiods: pain reliever, bind to opioid receptors
5. Psychostimulants; increase arousal, caffeine inhibits the inhibition of ATP production

Question 22

What are Antipsychotics?

Answer 22

Drugs that are used to treat psychoses.
1st generation affects libido and motor function
2nd generation has a broad-spectrum of side-effects

Question 23

What are Antidepressants?

Answer 23

Drugs that relieve major depressive disorder, they prevent the breakdown of dopamine

Question 24

What are Anxiolytics?

Answer 24

Drugs that help calm an over-aroused nervous system, work as GABA agonists increasing general CNS inhibition

Question 25

What are Opioids?

Answer 25

Opiods are pain relievers and cause euphoria, affecting opioid receptors

Question 26

What are cannabinoids?

Answer 26

Cannabinoids bind to cannabinoid receptors and infleunce hunger, memory and stress

Question 27

What are psychostimulants?

Answer 27

stimulants which increase arousal and vigilance. An example would be caffeine which inhibits the inhibition of ATP production (to give you energy)

Question 28

What is alcohol?

Answer 28

Ethyl alcohol is a CNS depressant which primarily acts as a GABA agonist

Question 29

What are Hallucinogens?

Answer 29

Hallucinogens are a class of drugs which cause a dreamlike change in perception, an example are psychedelics which change touch and thought.

Question 30

What are the rat park experiments?

Answer 30

Animals raised in a natural environment with healthy social outlets rarely chose morphine over water.

Question 31

What are the four types of drug tolerance?

Answer 31

Drug tolerance is the process in which drugs effects those using them less the more that they use them. 1. Acute tolerance; occurs within a single session, the quick adaptation to a drug 2. Metabolic tolerance; occurs when more enzymes are produced to break down drugs 3. Cross-tolerance; one drug affects the same receptors as another drug 4. Behavourl tolerance; pre-adapts to cues of drug use

Question 32

What is the common pattern of expression when drug addiction does occur?

Answer 32

1. Withdrawl from the drug can lead to increased use 2. Tolerance, needing more to have the same effect 3. negative life consequences of use 4. Using more o the drug to relive withdrawal and pain/anxieties

Question 33

What are hormones?

Answer 33

Hormones are chemical messengers which travel through the the blood circulatory system to target cells

Question 34

What are the two types of Hormone Receptors?

Answer 34

metabotropic receptors used by peptide and steroid hormones, intracellular (nuclear) receptors used to regulate the expression of genes

Question 35

What is the cycle of social behaviour effects?

Answer 35

1. Change in hormone release 2. Change in behaviour 3. Change in experience

Question 36

What is the relationship between the hypothalamus and the pituitary gland?

Answer 36

The hypothalamus and the pituitary gland are anatomically and functionally connected. The hypothalamus maintains homeostasis and releases hormones through the pituitary gland. The pituitary gland has two lobes, the anterior pituitary gland and the posterior pituitary gland. the anterior pituitary gland when it receives signals from the hypothalamus creates and secrets hormones. For example the hypothalamus releases Corticotropin-releasing hormone (CRH) which stimulates the release of adrenocotrophic hormone (ACTH) which goes to the adrenal gland to release it's hormones. As for the posterior pituitary gland, the hypothalamus will also stimulate the posterior pituitary gland to release hormones, but it's hormones are made in the hypothalamus and only stored in the posterior pituitary gland.