Psychopharmacology

Question 1

what is bioavailability determined by

Answer 1

1. Route of administration
2. Dose
3. Rate
4. Absorption
5. Elimination
6. Kinetics

Question 2

Kinetics are determined by………

Answer 2

Kinetics are determined by factors such as the route of administration

Question 3

what does the Blood brain barrier do

Answer 3

Blood brain barrier preserves the internal environment of the brain, and will screen out most foreign agents.
Endothelial cells that surround the brain. They do not let things pass into the brain (e.g. bacteria, compounds)

Question 4

what are endothelial cells

Answer 4

Endothelial cells that surround the brain. They do not let things pass into the brain (e.g. bacteria, compounds)

Question 5

how is the brain hydrated

Answer 5

4-nanometer walls for water to diffuse across. This keeps the brain hydrated

Question 6

what is the dose-response curve

Answer 6

• Increase dose, response you are interested in goes up. Eventually tends to plateau.
• Plots the dose of the drug against is measured effect.
• Psychoactive effects tend to show S shaped curves due to upper limit of neural firing rates

Question 7

what is ED50

Answer 7

• ED50- means effective dose 50. This is where the drug produces 50% of its maximum affect

Question 8

what is margin of safety/therapeutic index

Answer 8

difference between an effective dose and a dose that produces toxic side effects

Question 9

how do Psychoactive drugs act on receptors

Answer 9

Psychoactive drugs act on receptors on neurons, which open ion channels, which change the electrical potential of the membrane and so change psychological experience.

Question 10

what do antagonists do

Answer 10

Antagonists block the receptor

Question 11

what are Inverse agonists-

Answer 11

Inverse agonists- bind to receptor but make ion channel work in reverse direction to usual

Question 12

copy up figure 4.4 here

Answer 12

ye

Question 13

where are Major acetylcholine projections from

Answer 13

Major acetylcholine projections are from the pedunculopontine nucleus, and the nucleus Basalis of Maynert but there are other minor cholinergic systems.

Question 14

Acetylcholine increases the signal to noise ratio where

Answer 14

Acetylcholine increases the signal to noise ratio in the firing rate to the specific stimulus to which the neuron is tuned.

Question 15

does Acetylcholine affect sleep

Answer 15

yes
Deep brain stimulation of the pedunculopontine acetylcholine neuron is patients with Parkinson’s disease produced sudden onset sleep and dreaming

Question 16

systems involved in dopamine

Answer 16

Nigrostriatal system SN projects to (-) Striatum
Mesolimbic system VTA-NA
Mesocortical system VTA-Frontal cortex

Question 17

Electrical self stimulation example

Answer 17

Rats quickly learn to self-administer electrical stimulation of the medial forebrain bundle, the middle of the mesolimbic dopamine pathway from the VTA to nucleus accumbens.

Found if they stimulated the brain at a certain point in the box, the rat would go back to that spot.

In the experiment, the rat could pull a lever to get a pleasure feeling in the brain

Question 18

what are ratbots

Answer 18

Rewarding rats with medial forebrain bundle stimulation for moving in a particular direction in response to virtual whisker stimulation, achieves an incredible level of control over the rats’ movement.

Question 19

where are Norepinephrine cells located

Answer 19

Norepinephrine cells bodies are located in the locus coeruleus and project broadly across the whole brain.

Question 20

The locus coeruleus noradrenaline system is thought to play two roles in attention.

Answer 20

1. Baseline LC activation = alertness.

2. Phasic LC activation = attention to goal-relevant stimuli

Question 21

example of 2. Phasic LC activation

Answer 21

Oddball stimuli produce spikes in LC activation, and the P300 cortical activation in humans.

Question 22

where does Serotonin (5HT) origiante

Answer 22

5HT cell bodies originate in Raphe nuclei in the brain stem and project to the spine, cerebellum, sub-cortex and cortex.

Question 23

what does 5HT play a role in

Answer 23

5HT is commonly understood to play a role in depression and mood. Antidepressant medications increase on 5HT via different mechanisms

Question 24

what is Glutamate is responsible for [

Answer 24

Glutamate is responsible for changing synaptic weight and thus learning

Question 25

what is GABA

Answer 25

GABA plays a major role in inhibition, capping the upper limit of cell firing rate through Renshaw cells

Question 26

gaba is a counterpoint to what

Answer 26

glutamate

Question 27

what is epilspy

Answer 27

Epilepsy is a failure of GABA inhibition to constrain excitatory loops in the brain. Most medications for epilepsy act to increase GABA inhibition, or decrease glutamate excitation

Question 28

what are endorphins

Answer 28

Endorphins inhibit transmission of pain signals in peripheral nervous system, and the central nervous system

Question 29

what releases endorphins

Answer 29

Endorphins released by the pituitary form part of the fight or flight stress response, and act on presynaptic opioid autoreceptors on pain signalling neurons.

Question 30

what happens when Endorphins are microinjected into the nucleus accumbens

Answer 30

Endorphins microinjected into the nucleus accumbens (terminal of the mesolimbic dopamine pathway) increase hedonic facial reactions to sweet flavour, and decrease aversive reactions to bitter flavour (in rats) suggesting a role in subjective euphoria.

Question 31

what is norepinephrine

Answer 31

Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as a hormone and neurotransmitter. … The general function of norepinephrine is to mobilize the brain and body for action

Question 32

what is analgesia

Answer 32

reduced sensitivity to pain