Psychopharmacology Flashcards
what is bioavailability determined by
- Route of administration
- Dose
- Rate
- Absorption
- Elimination
- Kinetics
Kinetics are determined by………
Kinetics are determined by factors such as the route of administration
what does the Blood brain barrier do
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)
what are endothelial cells
Endothelial cells that surround the brain. They do not let things pass into the brain (e.g. bacteria, compounds)
how is the brain hydrated
4-nanometer walls for water to diffuse across. This keeps the brain hydrated
what is the dose-response curve
- 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
what is ED50
• ED50- means effective dose 50. This is where the drug produces 50% of its maximum affect
what is margin of safety/therapeutic index
difference between an effective dose and a dose that produces toxic side effects
how do Psychoactive drugs act on receptors
Psychoactive drugs act on receptors on neurons, which open ion channels, which change the electrical potential of the membrane and so change psychological experience.
what do antagonists do
Antagonists block the receptor
what are Inverse agonists-
Inverse agonists- bind to receptor but make ion channel work in reverse direction to usual
copy up figure 4.4 here
ye
where are Major acetylcholine projections from
Major acetylcholine projections are from the pedunculopontine nucleus, and the nucleus Basalis of Maynert but there are other minor cholinergic systems.
Acetylcholine increases the signal to noise ratio where
Acetylcholine increases the signal to noise ratio in the firing rate to the specific stimulus to which the neuron is tuned.
does Acetylcholine affect sleep
yes
Deep brain stimulation of the pedunculopontine acetylcholine neuron is patients with Parkinson’s disease produced sudden onset sleep and dreaming
systems involved in dopamine
Nigrostriatal system SN projects to (-) Striatum
Mesolimbic system VTA-NA
Mesocortical system VTA-Frontal cortex
Electrical self stimulation example
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
what are ratbots
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.
where are Norepinephrine cells located
Norepinephrine cells bodies are located in the locus coeruleus and project broadly across the whole brain.
The locus coeruleus noradrenaline system is thought to play two roles in attention.
- Baseline LC activation = alertness.
2. Phasic LC activation = attention to goal-relevant stimuli
example of 2. Phasic LC activation
Oddball stimuli produce spikes in LC activation, and the P300 cortical activation in humans.
where does Serotonin (5HT) origiante
5HT cell bodies originate in Raphe nuclei in the brain stem and project to the spine, cerebellum, sub-cortex and cortex.
what does 5HT play a role in
5HT is commonly understood to play a role in depression and mood. Antidepressant medications increase on 5HT via different mechanisms
what is Glutamate is responsible for [
Glutamate is responsible for changing synaptic weight and thus learning
what is GABA
GABA plays a major role in inhibition, capping the upper limit of cell firing rate through Renshaw cells
gaba is a counterpoint to what
glutamate
what is epilspy
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
what are endorphins
Endorphins inhibit transmission of pain signals in peripheral nervous system, and the central nervous system
what releases endorphins
Endorphins released by the pituitary form part of the fight or flight stress response, and act on presynaptic opioid autoreceptors on pain signalling neurons.
what happens when Endorphins are microinjected into the nucleus accumbens
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.
what is norepinephrine
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
what is analgesia
reduced sensitivity to pain
