Ch. 2 -Synapse Flashcards
What evidence led Charles Sherrington to conclude that transmission at a synapse is not the same as transmission along an axon?
He forund that the velocity of conduction through a reflex arc was slower than the velocity of an action potential along an axon. Therefore, some delay must occur at the junction between one neuron and
the next
The difference between temporal summation and
spatial summation?
Temporal summation is the combined effect of quickly repeated stimulation at a single synapse. Spatial summation is the combined effect of several nearly simultaneous stimulations at several synapses onto one neuron
What was Sherrington’s evidence for inhibition in the nervous system?
He found that a reflex that stimulates a flexor muscle prevents contraction of the extensor muscles
of the same limb. He therefore inferred that an inter- neuron that excited motor neurons connected to the flexor muscle also inhibited the input to the extensor muscle.
What ion gates in the membrane open during an EPSP? What gates open during an IPSP?
During an EPSP, sodium gates open. During an IPSP, potassium or chloride gates open.
Can an inhibitory message flow along an axon?
No.
Only action potentials propagate along an axon. Inhibitory messages IPSPs decay over time and distance.
Hva er en synapse
The point of communication between two neurons
In the membrane of a neuron, what happens during an IPSP?
The potassium or chloride gates open
In what way were Sherrington’s conclusions important for psychology as well as neuroscience
He demonstrated the importance of inhibition
