People/Experiments
Describe the experimental setup to determine electrical transmission?
Sub-threshold current was injected into both cells in both positive and negative directions and then responses were recorded in both cells
small, spontaneous, random, slower and travel less than action potentials
Which requires extracellular calcium?
chemical only
What is the equation for mean quantal content (m)?
m=amplitude of average response to nerve stimulation/average mini amplitude (q)
Who proposed that neurotransmitter release involves opening of a gate to release a flood of ions?
Del Castillo and Katz
Define the quanta hypothesis
neurotransmitters are released in discrete packets (quanta) from the presynaptic cell
Which can amplify?
Chemical
How does mean quantal content change as there are repeated minis?
increases
What did Katz study to show probability of neurotransmitter release?
Frog NMJ
about 10,000 ACh
Which can transmit presynaptic hyperpolarization?
usually electrical, chemical can if cell has depolarized resting potential and stops releasing neurotransmitter when hyperpolarized
Poisson equation
P(k quanta released)=(e-m x mk)/k!
Who found the two components of inhibition?
Dudel and Kuffel
Define short term facilitation
as there is repeated stimulus, the amplitude of postsynaptic potential increases more
Which more easily allows plasticity?
m=npqCF
n=number of sites that can release ACh
p=probability of release at each site
q=amplitude of each quantal response
CF=correction factor for non-linear summation
Describe the importance of "dimples" in the rapid freezing experiments
The dimples would first appear as neurotransmitters were being released and more dimples appeared when more neurotransmitter was released
Evolutionary reasons for electrical synapses
increased speed, synchronization
Which can act bidirectionally?
electrical
You have a synapse with lots of neurotransmitter release sites but very low probability of release. Which statistical model would you use?
Poisson