Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
63 Cards in this Set
- Front
- Back
|
Why are most mechanisms of action of neuropharmacologic drugs approximations?
|
Approximations are made from information regarding effects of drugs in an isolated system. Extrapolation from biochemical events to behavior is difficult.
|
|
|
What is meant by the CNS being a "black box"?
|
You put the drugs in and the output is the behavior. You dont know how to explain the process of how it works.
|
|
|
What is specific mechanism of action?
|
A specific drug action affects a recognized protein target, i.e. receptor, ion channel, enzyme or transporter
|
|
|
Describe the various events in synaptic transmission which might be altered by drugs.
|
1. Action potential in presynaptic fiber
2. Synthesis 3. Storage 4. Metabolism 5. Release 6. Reuptake 7. Degradation 8. Receptor for the transmitter 9. Receptor-induced increase or decrease in ionic conductance 10. Synaptic transmission can be depressed by blockade of transmitter synthesis or storage |
|
|
What are the 2 consequences of drug-induced alterations of membrane potential?
|
Excitatory and inhibitory
|
|
|
What is EPSP?
|
Excitatory
Partially depolarize --> closer to threshold more likely to get the fire |
|
|
How can you increase the size of the depolarization?
|
Increase the stimulus strength --> threshold for spike generation is reached
|
|
|
How can drugs make affect the nerves?
|
It makes the nerves more ready to fire by changing the resting membrane potential.
|
|
|
What is IPSP?
|
Inhibitory --> more electronegative and less likely to fire
|
|
|
What does the inhibitory pathway do?
|
It prevents the excitatory potential from reaching threshold.
|
|
|
What is a neurotransmitter?
|
Substance that is released (by nerves) locally and causes change in post-synaptic potential. IPSP or EPSP
|
|
|
What is a neuromodulator?
|
A substance which acts to modify the response of the synapse to a neurotransmitter --> increases or decreases intensity of action
|
|
|
What are the substances that have been proposed to act as CNS NT?
|
Acetylcholine
Amino acids Biogenic amines Peptides Purines (ATP, adenosine) Nitric oxide |
|
|
What areionotropic receptors?
|
Associted with ion channels, and change ionic conductance; fast synaptic transmission
|
|
|
What are metabotrophic receptors?
|
Coupled with enzymes via G-proteins and other intermediates; calcium and potassium channels work this way
|
|
|
What is the BBB?
|
A diffusional barrier retarding the passage of substances from the central circulation to nerve cells
|
|
|
What characteristics regulate diffusion through capillaries?
|
Molecular weight
Lipid solubility Ionization |
|
|
What are the anatomical differences in CNS capillaries that are barriers?
|
Less permeable
tight junctions few pinocytotic sites surrounded by pericytes and astroglial processes carrier mediated transport |
|
|
What is the function of cognitive processing?
|
Interpretation of sensory information
|
|
|
What is a disorder of cogntive function?
|
Delirium-interpret the information wrong
|
|
|
What is the function of memory?
|
Results in motor activity, reasoning, forethought; ability to recall events
|
|
|
What is a disorder of memory?
|
Dementia and amnesia
|
|
|
What is the function of emotional processing?
|
COnscious perception of neuronal activity
|
|
|
What is a disorder of emotional processing?
|
Anxiety, mood disorders and schizophrenia
|
|
|
What is the function of sensory processing?
|
Bringing information in-vision, hearing, olfaction, touch, and pain
|
|
|
What is a disorder of sensory processing?
|
Sleep disorders, chronic pain (leads to changes in processing)
|
|
|
What is the function of motor processing?
|
Control of motion and posture
|
|
|
What is a disorder of motor processing?
|
Parkinson's Disease, degenerating and demylinization diseases
|
|
|
What does ACh bind to?
|
Muscarinic and nicotinic receptors
|
|
|
What happens when M1, 3, 5 binds with ACh?
|
Increase in IP3 and DAG
|
|
|
What happens with M2 and M4 bind to ACh?
|
Decrease in cAMP and increase in K
|
|
|
What happens when ACh binds to nicotinic receptors?
|
Inrease in Ca, K, and Na
|
|
|
How does Prozac work?
|
Inhibits reuptake of serotonin --> increases amt of serotonin in synapse
|
|
|
Is GABA inhibitory or excitatory?
|
Inhibitory
|
|
|
Is glycine inhibitory or excitatory?
|
Inhibitory
|
|
|
Is Glutamate and asparatate inhibitory or excitatory?
|
Excitatory
|
|
|
What is signal transduction?
|
Process by which signals are channeled from the outside of cell to inside
|
|
|
What may happen if ionotropic receptors are activated?
|
Inrease chloride, Na, K, or Ca conductance and cause excitatory or inhibitory membrane potentials
|
|
|
What can activation of metabotropic receptors lead to?
|
Synthesis of cAMP, IP3, and DAG which can altera variety of intracellular pathways
|
|
|
If the drug is lipid soluble, will it pass the BBB?
|
Yes
|
|
|
Will ionized drugs cross the BBB?
|
No, ionized drugs are not lipid soluble
|
|
|
Will an unionized drug cross the BBB?
|
Yes, and it alter the CNS activity
|
|
|
What pathway does NE follow in the CNS?
|
Noradrenergic pathway --> mainly in medial forebrain bundle and descending spinal tracts, terminate diffusely in cortex, hippocampus, hypothalamus, cerebellum, and spinal cord
|
|
|
What actions does noradrenaline have?
|
Maily inhibitory (Beta-adrenoceptors) but some are excitatory (alpha or beta adrenoceptors)
|
|
|
What is NE transmission believed to be important in?
|
Arousal system-controlling wakefulness and alertness
Blood pressure regulation Control of mood (functional deficiency contributing to depression) |
|
|
What are the three main Dopamine pathways in the CNS?
|
Nigrostriatal
Mesolimbic/mesocortical Tuberohypophyseal |
|
|
What does the Nigrostriatal pathway control?
|
Important in motor control
|
|
|
What is the Mesolimbic/mesocortical pathways responsible for?
|
Involved in emotion and drug-induced reward systems
|
|
|
What is the Tuberohypophyseal pathway?
|
Regulate secretions from pituitary gland
|
|
|
What do the Dopamine receptors D1 and D5 do?
|
Stimulate adenylate cyclase
|
|
|
What does D2, D3, and D4 receptors do?
|
Inhibit adenylate cyclase
|
|
|
What receptors may be implicated in schizophrenia?
|
D2 family
|
|
|
What receptor shows marked polymorphism in humans?
|
D4
|
|
|
What is Parkinson's associated with?
|
Deficiency of nigrostriatal dopaminergic neurons
|
|
|
What is 5-Hydroxytryptamine or 5-HT in the CNS?
|
Serotonin
|
|
|
Where is serotonin (5-HT) located?
|
Concentrated in midline raphe nuclei in pons and medulla, projecting diffusely to cortex, limbic system, hypothalamus, and spinal cord
|
|
|
What are the funtions associated with 5-HT?
|
Feeding behavior
Control of mood and emotion Various behavior responses Control of sleep-wakefullness Control of sensory pathways Vomiting |
|
|
Is NMDA inhibitory or excitatory?
|
Excitotory
|
|
|
What are the two types of GABA receptors?
|
GABAa
GABAb |
|
|
What does GABAa do?
|
Mainly postsynaptically --> directly coupled to chloride channels, opening of which reduces membrane excitability
|
|
|
What drugs interact with GABAa receptors and channels?
|
Benzodiazpine
Convulsants Neurosteriods |
|
|
What does GABAb do?
|
Are G-protein coupled --> linked to inhibition of cAMP formation --> pre and post synaptic inhibition by inhibiting calcium channel opening and increasing K conductance
|
|
|
What drug will interact with GABAb receptor?
|
Baclofen--a GABAb receptor agonist used to treat spasticity
|
