Hoorcollege samenvattingen Psychofarmacologie UU

Psychopharmacology
HC 1 – General Introduction
What is a pharmacon or drug?
➢ Substance that is administered to the body and influences physiological processes
➢ Can be body’s ow substance
- Psychoactive substances: influence processes in the brain and behavior and affect +
cognition
- Can be either therapeutic or recreational (study question)

What is Pharmacology?
➢ Science that studies the influence of substances on biological processes
➢ Psychopharmacology focusses on their effects on behavior, cognition and affect incl their
mechanisms in the brain

Pharmacokinetics -> How does the substance move through the body?

Pharmacodynamics -> How does the body react to the body?

Neurotransmitters and neurotransmission
- What is involved in neurotransmission?
➢ Neurons
➢ Action potentials
➢ Synapse
➢ Transmitter
• Synthesis
• Release
• Degradation
➢ Receptor

Activation of receptors
- Intra- and extracellular space divided by a membrane
- Potential difference inside/outside (resting potential +- 70mV)
- Neurotransmitters act on neurons via receptors
- Effect: small change with respect to the resting potential (-70mV) (ESPS/IPSP) that can add up to the
threshold for an action potential

,Chemical messengers in synapse




Specific Neurotransmitters:
- <1%: NE, DA, 5-HT
- relatively specific target for drugs, since they are located in specific areas

Frequent (50%) neurotransmitters:
- GABA, Glu, endocannabinoid receptor

Even though implicated in disorders/effects compounds:
- GABA: alcohol, sedatives, anxiolytics
- Gly, NMDA: epilepsy, Huntington, aids dementia, schizophrenia
-> Problem: many neurotransmitters scattered in the entire body, so side-effects more likely since
the neurotransmitters in other areas will be affected as well

Specific neurotransmitters, where from?

Monoamines (singe amine group)
- Catecholamines: DA, NE, E
* Precurser: tyrosine -> DOPA -> DA -> NE -> E

Indolamines: 5-HT
* Precursor: tryptophan

Amino acid
- Glu, GABA
* Precursor: glucose

,ACh
* Precursor: choline/lecithin.

Peptides
- oxytocin, endorphines
*Precurser Amino Acids



Types of receptors (based on location on cell)
- Post synaptic, axon dendritic (3)
> Most typical type
- Presynaptic
> Auto receptor (1)
• Detects release of NT from own
neuron
> Heteroreceptor (4)
• Modulates synapse from another
neuron
> Auto receptors on other locations
on the cell, like on a dendrite (2)



Types of neurotransmissions
- Synaptic axo-dendritic is the most typical form, but there is also:
➢ Retrograde transmission
➢ Nonsynaptic diffusion (volume transmission)
➢ Neuromodulators
• Endogenous benzodiazepine
➢ Neurohormones
• Like CRH (Corticotrophin Releasing Hormone)
• HPA-axis; fear/stress -> cortisol

, Neurotransmitters and their functions




Different subtypes are important for the exam, just the functions, not receptors.

How do the neurotransmitters get degraded?
- Combination of degradation (metabolism) in synapse and reuptake within the cell
➢ Ach: degradation extracellular by enzyme AChE (then reuptake)
➢ 5-HT: reuptake (and intracellular degradation
➢ Peptides: (proteins, amino acid chains, degradation by peptidases, then diffusion)