|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 5. Large angle C-start responses to dark-flash stimuli are Mauthner
independent. (A) Laser ablation of Mauthner cells. Cell bodies (asterisks) and
axons (arrows) visible in control lesions (top) are absent in
immunohistochemical staining 48 h after ablation (bottom), while fibers
coursing around the Mauthner cells, including the axon cap (arrowheads) are
unaffected. Scale bar, 20 µm. (B) High performance startle responses
elicited by acoustic/vibratory stimuli in control larvae (`control',
N=8) are completely abolished after bilateral Mauthner cell lesion
(`ablation', N=6 larvae). Slower, long latency responses to the same
stimulus are not affected by Mauthner cell lesions (data not shown). (C)
Mauthner cell ablation does not impair dark-flash responsiveness in the same
set of larvae, showing that O-bend responses to dark-flash stimuli are not
initiated by the Mauthner cell startle circuitry (two-tailed t-test,
P=0.89). Larvae were tested individually with a series of 10 dark
flash stimuli from 65 µW cm–2 to darkness, at 1 min
intervals. (D) O-bend kinematics during the dark-flash test in control larvae
(`C') and ablated larvae (`A') are almost identical, arguing that the Mauthner
cell is not involved in larval dark-flash responses. No statistical
differences are present between any pair of kinematic values (two-tailed
t-test, P>0.1 for all measures). Values are means
± s.d. of O-bend responses.
|
