2.3 Electrical and chemical synapses

Question 1

what is the main difference in time between electrical and chemical synapses?

Answer 1

Chemical:
- ionotropic (1ms)
- metabotropic (sec-min)

electrical:
- instantaeous

Question 2

where were the first elecrtical synapses found?

Answer 2

in cray fish (1957)

Question 3

what makes a connexon?

part of an elecrical gap junction

Answer 3

6 connexins

and each connexin is made of 4 parts

Question 4

what ion causes gap junctions to close?

Answer 4

Ca2+

the connexin subunits are tilted 7-8 degrees from an axis perpendicular

Question 5

homotypic channel vs. heterotypic channel

Answer 5

homotypic channel: opposite side is the same

heterotypic channel: the opposite side is different connexon hexamers

Question 6

hemichannels vs. gap junctions

Answer 6

gapjunctions are connected to another cell & allow intracellular messengers through (Ca2+, IP3, cAMP, glutamate, glucose)

hemichannels are similar to gapjunctions but are facing the extracellular space and facilitate two way transfer between the cytosol and extracellular space

Question 7

synaptic bouton

Answer 7

small swellings that are found at the terminal ends of axons. Synaptic boutons are the sites where synapses are found and is where neurotransmitters NT are stored in vesicles

Question 8

dendritic spines

Answer 8

dendritic spines are protrusions from a neurons dentride that recieces a synaptic input from an axon. This is where neurotransmitter Recepters are located

Question 9

What are the V dentrite sizes

Answer 9

type I: Filipodium
type II: Thin
type III: Stubby
Type IV: mushroom
Type V: cup shaped