Mcb 80 - Lecture 7 Quiz Questions

Front 1

Briefly define Gap junction.

Back 1

allow current (ions) to flow between pre- and postsynaptic cells; direct electrical communication between cells

Front 2

Define Electrical synapse.

Back 2

Pre- and postsynaptic membranes in direct contact; Permeable to molecule, including Na, K, Ca, and Cl

Front 3

Define Synaptic vesicle.

Back 3

store the various neurotransmitters that are released during calcium-regulated exocytosis at the presynaptic terminal into the synaptic cleft of a synapse.

Front 4

Define Active zone.

Back 4

a dense patch of synaptic vesicles

Front 5

Define Postsynaptic density.

Back 5

a cytoskeleton specialization at neuronal synapses; usually comprised of L-glutamate neurotransmitter receptors

Front 6

Define Synaptic cleft

Back 6

specialized junctions through which the cells of the nervous system signal to each other and to non-neuronal cells such as those in muscles or glands; allow chemical intermediate (neurotransmitter) to pass from cell to cell

Front 7

Define EPP.

Back 7

End plate potential; EPSP of neuromuscular junction

Front 8

Define MEPP.

Back 8

Miniature end plate potentials; subunits from which an EPP is made up

Front 9

Define Exocytosis.

Back 9

process by which a cell directs secretory vesicles out of the cell membrane; method by which neurotransmitters are released by the presynaptic membrane

Front 10

Define Endocytosis.

Back 10

process where cells absorb material, such as during reuptake

Front 11

What are two advantages of electrical synapses compared to chemical ones?

Back 11

Quicker such that do not have to wait for transduction; use less energy

Front 12

What are two advantages of chemical synapses compared to electrical ones?

Back 12

Multiple types of chemicals; integration and modulation of signal

Front 13

What key piece of evidence proved that most synapses use chemical rather than electrical transmission?

Back 13

Electron microscopy

Front 14

What were the main contributions of Bernard Katz to neuroscience?

Back 14

proposed the quantal, vesicle, and calcium hypothesis, thereby setting the stage for the SNARE hypothesis, which is the molecular basis of the other three

Front 15

What is the quantal hypothesis of neurotransmission and what key pieces of evidence support it?

Back 15

neurotransmitter is released in multimolecular “packets” of a fixed size

Front 16

What is the vesicle hypothesis of neurotransmission and what key pieces of evidence support it?

Back 16

synaptic vesicles are structural basis of quanta

Front 17

What is the SNARE hypothesis and what is the difference between vSNAREs and tSNARES?

Back 17

interactions between SNARE proteins on the vesicle and on the presynaptic membrane, modulated by calcium, lead to vesicle fusion; Vesicle fusion catalyzed by interaction of vesicle associated SNARE proteins (v-SNARES) with other SNARE proteins on the membrane with which fusion can occur (target SNARES or t-SNARES)

Front 18

What is the calcium hypothesis of neurotransmission?

Back 18

voltage-dependent calcium entry couples stimulation (the action potential) to secretion

Front 19

What is the Poisson distribution and how does it help synaptic physiologists?

Back 19

gives PNumber of events as f (n,p), when n is high, p is low, and each event is independent of the others

Front 20

How does botulinum toxin lead to respiratory failure?

Back 20

cleave and thereby inactive SNARE proteins; paralyze you by preventing neurotransmitter release