James Allen

Question 1

1. Early in development zebrafish larvae respond to auditory stimuli but then acquire a response to head/tactile stimuli later in development.

Answer 1

False

Question 2

2. Trigeminal ganglion input is necessary to elicit an escape response in younger larvae ( > 75 hpf)

Answer 2

True

Question 3

Lesions to which of the following structures would eliminate auditory input to the brain?

Answer 3

Otic vesicle contains the hair cells that mediate responses to auditory stimuli

Question 4

Which of the following is necessary for short latency escape reflex throughout development in zebrafish?

Answer 4

Mauthner cells were necessary for short latency response throughout development

Question 5

In Kohashi et al., 2012, the Oda lab was interested in the functional development of Mauthner cell circuitry and reported a developmental switch of sensory input to the M-cells. A. Describe the developmental switch of sensory input the group reported. (i.e. complete the sentence “Initially ____ input activates M-cell mediated escape response, but then after 75 hpf _____ input activates M-cell escape response instead). B. Describe how the group chose to either study the function or study the activity of this circuitry (i.e list one of the three major methods used by the group and describe its purpose for the experiment).

Answer 5

A. Initially head-tactile input activates M-cell mediated escape response, but then after 75 hpf auditory input activates M-cell escape response instead
B. Three major methods used by paper: 1. Transgenic fish, used to visualize specific cell types (Mauthner and trigeminal ganglion) in order to properly ablate them. 2. Laser ablations, used to lesion the Mauthner and trigeminal ganglion to study their role in the escape reflex. 3. Calcium Imaging, used to measure the activity of the Mauthner cell during the escape reflex, calcium influx indicated the firing of an action potential in the Mauthner cell.