History of Synaptic Transmission Flashcards
what determines behavior
-endogenous activity of the nervous system influenced by situational environment and organism needs
Ramon y Cajal, Dynamic Polarization
what’s a synapse
-when two neurons come in close proximity with one another to communicate (they do not touch)
chemical synapse
-One neuron secretes neurotransmitter that activates receptors on
another neuron
electrical synapse
-Neurons are in electrical continuity with one another via interlocking
proteins with ion channels
-ex. connexon channels
Galvani’s experiment
-Galvani discovered “animal electricity” by connecting the skeletal muscle of a dead frog leg to the spinal nerve causing the leg muscles to contract
-what was the actual cause of this
DuBois/Bernstein
-used a differential rheotome to record the first action potential waveform
Bernstein’s Breakdown Theory
-stated that depolarization beyond a certain threshold leads to a transient breakdown of the ionic barrier between inside and outside of the cell
-thought this results in the membrane being permeable to all ions equally
why was Bernstein’s Breakdown Theory found to be untrue
-equal permeability indicates that Ecell would equal 0mv at its peak value
Han’s Berger
-developed the first human EEG
Loewi’s experiment
-innervated one heart with the vagus nerve and connected fluid surrounding heart 1 with the fluid surrounding heart 2
-recorded that stimulation of the vagus nerve decreases firing rate of heart 1 and heart 2
Vagustoff
-the stuff which traveled through the continuous extracellular fluid between heart 1 and 2 through which acted as the chemical signaling compound
what evidence was there to support that chemical synaptic transmission could not be the mode of communication in the central nervous system?
time vs. inter-heartbeat period graph after stimulus of the vagus nerve shows too long of time lag between vagus nerve stimulation and slowing of heartbeat was too long
required process for chemical synaptic transmission
- neurotransmitter synthesis
- neurotransmitter release
- recognition of neurotransmitter message
- conversion of chemical signal to electrical signal
- clearing of neurotransmitter to stop the message
What did Eccles, Katz, and Kuffler discover
-the response latency at the neuromuscular junction is 100x smaller than the cns response to vagal stimulation
-this response latency is suitable for neuronal transmission