Neurotransmission and ANS Flashcards
How does botulinum toxin alter synaptic transmission?
It cleaves SNAREs and results in a flaccid paralysis of peripheral areas of the body.
How does tetanus toxin affect synaptic transmission?
It cleaves SNAREs and results in a spastic paralysis around the spinal cord area.
What is the effect of sarin nerve gas?
It inhibits the activity of acetylcholinesterase which increases the proliferation of acetylcholine and causes overstimulation that results in convulsions and paralysis and eventually death.
What are EPSPs?
Excitatory Post-Synaptic Potentials. If the neurotransmitter is excitatory (ACh/Glu) then the membrane will depolarize to around 0 mV. They are NOT APs though.
What are IPSPs?
Inhibitory Post-Synaptic Potentials. If the neurotransmitter is inhibitory (Gly/GABA) then metabotropic Cl channels open and the membrane potential hyper polarizes to -60 mV and reduces the chance for an AP.
Describe the differences between autonomic and central synaptic transmission.
The ANS uses metabotropic post- synaptic receptors with variable NT effects while the CNS uses fast ionotropic receptors with direct NT effect.
What is the difference between sympathetic and parasympathetic preganglionics fibers?
Sympathetic preganglionic fibers are shorter than parasympathetic fibers.
What is the difference between sympathetic and parasympathetic postganglionics fibers?
Sympathetic postganglionic fibers are longer that parasympathetic fibers.
What is special about the chromaffin cells of the adrenal medulla?
They can be considered postsynaptic neurons because preganglionic axons directly synapse with the medulla and there are no postsynaptic neurons.
What is the NT of the parasympathetic preganglionics?
Acetylcholine
What is the NT of the parasympathetic postganglionics?
Acetylcholine
What is the NT of the sympathetic preganglionics?
Acetylcholine
What is the NT of the sympathetic postganglionics?
Norepinephrine and Epinephrine
What is an exception to the sympathetic postganglionics?
Sweat glands use ACh on the postganglionic fibers
What type of receptors do the sympathetics use?
Adrenergic - Metabotropic