psychopharmacology

psychopharmacology

study of the effects of drugs on the nervous system and behavior

drug effects

changes in physiology and behavior following the ingestion of a drug; analgesia, euphoria, etc.

sites of action

are the biological sites at which drug molecules bind to or interact with cells in order to alter their physiological processes

four principles of pharmacokinetics

absorption - how will it get in; distribution - where will it go (transporters); metabolism - how is it broken down (liver); excretion - how does it leave

blood brain barrier

prevents most water-soluble molecules from entering the brain

lipid soluble

molecules are most likely to reach the brain

dose - response curves

are graphs that show how effective a drug is depending on how much is administered

margin of safety

difference between the desired

therapeutic index

the ratio between the ED-50 and LD-50

affinity

level of attraction between drug and binding site

narcan

opioid overdose drug, extremely competitive

tolerance

When repeated administration of the drug causes a decrease in the effectiveness of that drug

sensitization

When repeated administration of the drug causes an increase in the effectiveness of the drug

allostatic load

created by repeated use then
causes withdrawal because of the compensatory
physiological changes caused by the drug

physical dependence

when the allostatic load has become strong enough to produce physical symptoms in the absence of the drug

compensatory changes

1. Decrease or increase in the effectiveness of receptor binding
2. Increase or decrease in the number of receptors available for binding
3. Ion channels coupled to receptors become less effective
4. Second messenger systems become less effective

placebo

inactive substances that contain no active drug molecules

placebo effect

inactive substances that contain no active drug molecules

vesicular transporters

neurotransmitters that are packaged into vesicles by proteins

direct antagonist

drug binds directly to receptor to activate it

noncompetitive binding

occurs when a drug molecule binds to one of these secondary sites

agonist

drugs that prevent increase amount of neurotransmitter at the synapse by blocking either of these causes changes in cellular activity

neurotransmitter

a chemical used for neuron to neuron communication

neuromodulator

chemicals that effect the neurotransmission of a whole group of different neurons in order to effect how they receive communication

gaba

inhibitory transmitter that is ubiquitous in the central nervous system

glutamic acid decarboxylase

synthesized as part of the degradation of glutamate

nigrostriatal

dopamine system projects from the substantia nigra to the basal ganglia

mesolimbic

dopamine system projects from the VTA to the limbic system (including nucleus accumbens, amygdala, and hippocampus

mesocortical

dopamine system projects from the VTA to limbic cortex (prefrontal)

histimine system

roles in wakefulness; antihistamines cause drowsiness (newer ones do not break blood brain barrier); produced from histidine by the enzyme histidine decarboxylase

neuropeptides

• Consist of two or more amino acids linked by peptide bonds (large)
• Produced from Large precursor molecules by enzymes
• Released from all parts of the terminal
• Co-released with neurotransmitter
• No Reuptake mechanism

positive effect of endocannabinoids

• Analgesia
• Sedation
• Reduced nausea
• Decreased ocular pressure

negative effects of endocannabinoids

• Impairs concentration
• Affects memory
• Alters sensory perception and time perception