Week5: T3(1): Pharmacological interventions: medications and their effects Flashcards
What is a presynaptic neuron?
The neuron that releases neurotransmitter
What is a postsynaptic neuron?
The neuron that is receiving the information.
What is a synapse?
Gap between pre-and postsynaptic neurons; about 20 nanometers.
What is agonist?
A compound that binds to a receptor and causes a biological response. Neurotransmitters that come within the brain are agonists; they cause biological response when they bind. Ex. Dopamine, serotonin, acetylcholine, GABA, glutamate.
What is antagonist?
An antagonist is a medication that binds to a receptor and blocks a biological response. Many medications are antagonists - they block a response.
What is all endogenous ligand?
Neurotransmitter that comes within the brain. A ligand is a protein that attaches (binds) to another protein called a receptor; receptor proteins have specific sites into which the ligands fit like keys into locks. Endogenous ligands are those that are produced in the body, not those introduced into the body, such as certain drugs.
Antipsychotics
- Antipsychotics involve modulation of the dopaminergic system.
- They are are postsynaptic dopamine antagonists.
- Circulate widely, but (should) only affect dopamine receptors
- Antipsychotics target the mesolimbic pathway whose functions are regulating reward and salience. Specifically, the threat perception. People are more likely to become paranoid.
- For antipsychotic to be effective, it needs to block between 60 per cent and 70 per cent of that signal
What is dysphoria?
A lack of pleasure from everyday activities. Side effect of antipsychotic medication. A results of the medication disrupting the the reward processing part of the brain; the blockage of dopamine receptors is not only to the salient area but also the reward area.
What is iatrogenic?
Iatrogenic means ‘caused by medication, ’classical/typical antipsychotics can worsen negative symptoms with schizophrenic patients.
What are atypical medications?
Neuroatypicals for schysophrenia, block dopamine, but also increases dopamine release in certain parts of the brain, which are deprived from sufficient dopamine. In order to overcome the problem lack of drive, motivation and social engagement, there need to be more dopamine, not less.
They reduce enough dopamine excess in the mesolimbic system to treat paranoia, but they don’t cause the same problems in the frontal lobe. There are other side effects in terms of weight gain and more.
How do antipsychotics affect the nigrostriatal and the tuberoinfundibular?
The nigrostriatal helps regulate movement. The tuberoinfundibular, part of the hypothalmic-pituitary axis which is involved in hormonal or endocrine functions (breast milk, production, menstruation, libido). antipsychotics cause extrapyramidal side effects,
What are extrapyramidal side effects?
Movement problems caused by dysregulation of the nigrostriatal pathway, amenorrhea, galactorrhea and libido.
What are amenorrhea, which is the and galactorrhea.
Amenorrhea = cessation of menstruation, Galactorrhea = inappropriate production of breast milk
What is the monoamine hypothesis?
Depression is caused by a lack of serotonin and noradrenaline (which are monoamine NTs).
Research showed it was incorrect.
Depressed people have normal levels of serotonin and noradrenaline.
What is the refined hypothesis to the monamine hypothesis?
Depressed people have abnormal intracellular responses to these.