CNS Flashcards
CNS drugs can act on ___ and ___ receptors to produce an affect, causing one of what five actions?
pre and post synaptic receptors
- production
- storage
- release
- termination of action
- activate or block receptors
CNS is very similar to ANS in terms of the actions that occur at the synaptic clefts… what 3 things make it different?
- CNS= more complex and many more synapses
- CNS= strong inhibitory neuron network constantly modulating transmission
- CNS= More neurotransmitters
some drugs acting on the CNS do so by manipulating what two ion channel types?
- voltage-gated (response to changes in membrane potential- channel types: Na, K, Ca)
- ligand -gated: NTs bind receptors
ligand- gated ion channels: what are 3 types of receptor-channel coupling?
- receptor acts directly on channel
- Receptor is coupled to ion channel which is regulated by NTs and their receptors
- Receptor is coupled to G protein that activates 2nd messenger…
- Cyclic adenosine monophosphate (cAMP)
- Inositol triphosphate (IP3)
- Diacylglycerol (DAG)
Neurotransmitter bind to postsynaptic neuron receptor, elicits response and trigger what two things?
EPSP and IPSP
excitatory post-synaptic potential and inhibitory post-synaptic potentials
what are our two excitatory NTs?
Ach, glutamate
what are our two inhibitory NTs?
GABA and glycine
EPSP is generated by…
Binding to receptor= small depolarization to stimulate EPSP
–> increased permeability of Na+
–>increase intensity and more presynaptic fibers activated
When enough excitatory fibers activated get complete depolarization of postsynaptic neuron
IPSP is generated by…
Stimulation if inhibitory neuron =release of inhibitory NTs to bind to postsynaptic neuron
–> increased permeability of K+ and Cl- channels
–> hyperpolarization (which stops that transmission from going on)
This diminishes action potential and neuron firing
3 characteristics of NTs found in CNS
- Found in high concentrations in synaptic area
- Release via calcium-dependent mechanism
- Produce postsynaptic response resulting in physiologic activity
what are our 4 main types of NTs found in the CNS?
- Ach
- Amino acids
- Monoamines
- peptides
what are the amino acids in the CNS?
glycine, glutatame, GABA
what are the monoamines in the CNS?
Serotonin, histamine
Catecholamines:
Dopamine, Epinephrine, Norepinephrine
what are the peptides in the CNS?
endorphin, opioid peptides, substance P
binding of excitatory NT Ach causes ____ while binding of inhibitory NT GABA causes _____
depolarization (Na + enters cell)
hyperpolarization (Cl- enters cell)