The Nervous System: Synaptic Transmission

Question 0

A _________ junction is a plaque like structure in which the plasma membrane of _________ cells become closely apposed and filled with electron dense material.

Answer 0

Gap

Coupled

Question 1

The two main classes of synapses are:

Answer 1

electrical and chemical

Question 2

Gap junction _____-channels are composed of __________ and allow ________ and ____________ to flow through.

Answer 2

Hemi
proteins - connexin
ions and small molecules

Question 3

Electrical synapses are a ______ speed and ____-directional and act as _________ filters. This means that low pass electrical events are much more readily transmitted than are ______ signals.

Answer 3

fast
bi
slow
fast

Question 4

Electrical synapses can be modulated by : ________, intracellular ___, and the ______ ion.

Answer 4

voltage
pH
Ca

Question 5

Chemical synapses are generally ___-directional. ______ and _______ are typically found in the presynaptic terminal.

Answer 5

uni

mitochondria and RER

Question 6

________ channels opening and closing is determined by the binding of a neurotransmitter. When an ion is involved too they’re referred to as __________ receptors and underlie what is now called ______ synaptic transmission.

Answer 6

Ligand
Ionotropic
Fast

Question 7

The potential at which there is no EPSP or EPSC is known as the _________ and is usually around ____ mV. This only happens with __________/__________ gated channels.

Answer 7

Reversal potential
0
Chemical or ligand

Question 8

IPSP’s involve an increase in _________________ as a result of the opening of ______ gated channels. They are permeable to only _____ or ______ ions and thus will a ___________ potential equal to the Nernst potential of the ion carrying the current.

Answer 8

Membrane potential
Ligand
k or Cl
Reversal

Question 9

Action potentials usually happen at the __________ because it the highest density of _______ channels and therefore the ___________ threshold for initiation of a spike.

Answer 9

Axon hillock
Voltage gated Na channels
Lowest

Question 10

EPSPs generated near the Axon hillock will have a _________ depolarization. Thus the synapses location in the _________ tree is an important factor.

Answer 10

Larger

Dendritic

Question 11

The fact that EPSPs have a ________ time course facilitates _________ summation. Contrarily, ________ summation Refers to the fact synaptic potentials interact & depends on the ___________ relationship.

Answer 11

Longer
Temporal
Spatial

Question 12

One kind of Subthreshold stimulation is ____________. It is ______ acting and will cause a larger amplitude in a second stimulus.

Answer 12

Facilitation

Short

Question 13

__________ receptors mediate synaptic transmission which is ______ in onset and long on duration. The receptor and ________ channel are not part of the same molecule . It’s effect will depend on the specific ___________ activated.

Answer 13

Metabotropic
Slow
Ion
Second messenger

Question 14

__________ are the substances that mediate chemical signaling between neurons.

Answer 14

Neurotransmitters

Question 15

_________ act to decrease the release of substance P which inhibits that pathway for _________ . They are both __________.

Answer 15

Enkephlins
pain
Neuropeptides

Question 16

Electrical synapses are regulated by _____________ receptors and the connexins contain sites for _____________.

Answer 16

G protein

Phosphorylation