Lecture 23: Respiration 2

Question 1

What produces active expiration?

Answer 1

activation of RTN / pFRG

Question 2

What does respiratory rhythm (both inspiratory and expiratory) originate from? Where is it transmitted?

Answer 2

the brainstem and is transmitted to the spinal cord

Question 3

What sites are involved in the current view of respiratory rhythmogenesis?

Answer 3

pre-Bötzinger complex (inspiration)
postinspiratory complex (PiCo - post-inspiration)
RTN / pFRG (expiration)

Question 4

What is the respiratory neuronal network made up of?

Answer 4

continuous column of “respiratory neurons” from the pontine tegmentum to the origin of the spinal cord (PRG + VRG)

Question 5

What is the PRG and the VRG?

Answer 5

the pontine respiratory group and the ventral respiratory group

Question 6

What is the DRG?

Answer 6

the dorsal respiratory group = NTS

Question 7

Which regions is the ventral respiratory group subdivided into?

Answer 7

the Bötzinger complex, the pre-Bötzinger complex, the rostral ventral respiratory group and the caudal ventral respiratory group

Question 8

What are the types of respiratory neurons within the VRG?

Answer 8

I neurons, post-inspiratory neurons, E2 neurons and augmenting expiratory neurons

Question 9

What are these neurons classified by?

Answer 9

by the respiratory phase the neurons are active in

Question 10

What is respiratory rhythm generated by?

Answer 10

coordinated activity of respiratory neurons

Question 11

What type of neurons are BötC neurons?

Answer 11

post-I and aug-E neurons are inhibitory glycinergic

Question 12

What type of neurons are pre-BötC neurons?

Answer 12

pre-I/I neurons are excitatory glutamatergic and early-I neurons are inhibitory

Question 13

What type of neurons are rVRG neurons?

Answer 13

aug-I neurons are excitatory to motor output

Question 14

What is substance P and what receptor does it act on?

Answer 14

a neuropeptide which acts on the metabotropic receptor neurokinin 1 (NK1)

Question 15

What happens when substance P binds to neurokinin 1?

Answer 15

decreases potassium conductance

Question 16

What is the effect of decreasing potassium conductance on neuronal membrane potential?

Answer 16

becomes less negative

Question 17

What is the effect of injecting substance P into the Bötzinger complex?

Answer 17

will increase respiratory time / duration

Question 18

What is the effect of injecting substance P into the pre-Bötzinger complex?

Answer 18

will increase respiratory frequency

Question 19

What is the effect of injecting DLH (glutamate receptor agonist) into the Bötzinger complex?

Answer 19

slows breathing

Question 20

What is the effect of injecting DLH (glutamate receptor agonist) into the pre-Bötzinger complex?

Answer 20

speeds up breathing

Question 21

What does DLH act on? What does substance P act on?

Answer 21

ionotropic receptors

metabotropic receptors

Question 22

What is the pontine respiratory group important for?

Answer 22

the post-inspiratory phase

Question 23

What is BötC important for?

Answer 23

the expiratory phase

Question 24

What did caudal transection of pre-BötC result in?

Answer 24

abolished respiratory rhythm

Question 25

What would happen to the three-phase rhythm if GABA was microinjected into the pontine respiratory group?

Answer 25

increase respiratory frequency

Question 26

Following injection of GABA into the pontine respiratory group, how would expiratory duration change?

Answer 26

would be shortened

Question 27

With injection of glutamate into the pontine respiratory group, which neuronal subtype would have increased activity?

Answer 27

post-inspiratory