Locomotion in lower vertebrates

Question 1

what are 4 model organisms for CPG circuitry in lower vertebrates

Answer 1

frog tadpoles
lamreys
zebrafish
turtle

Question 2

what are 3 reasons we study CPG in lower vertebrates

Answer 2

simple behaviours, simple circuity, higher accessibility

Question 3

what is the basal ganglia –> CPG pathway in tadpoles

Answer 3

basal ganglia, mesencephaloc locomotor region, reticulospinal neurons, CPG

Question 4

what are the four types of CPG neurons in tadpoles

Answer 4

cIN- commissural interneurons(inhibitory)
aIN- ipsialteral ascending internuerons (inhibitory)
dIN- ipsilaterally descending interneurons (excitatory)
mR- motorneurons

Question 5

describe cINs

Answer 5

inhibit all CPG neurons on opposite side

left right coordination

Question 6

describe dINs

Answer 6

excite all CPG neurons on opposite side

Question 7

what is the hypothesis associated with dINs

Answer 7

rebound hypothesis

Question 8

what is the rebound hypothesis

Answer 8

dINs are earliest firing neurons in caudal hindbrain

Question 9

what is one mechanism of swimming in tadpoles

Answer 9

rebound firing based on feedback excitation among dINs and cIN inhibition