TY - JOUR

T1 - Swim pacemakers in box jellyfish are modulated by the visual input

AU - Garm, Anders Lydik

AU - Bielecki, Jan

N1 - Keywords Swim pacemaker - Cubomedusae - Vision - Inter-signal interval - Firing frequency

PY - 2008

Y1 - 2008

N2 - A major part of the cubozoan central nervous system is situated in the eye-bearing rhopalia. One of the neuronal output channels from the rhopalia carries a swim pacemaker signal, which has a one-to-one relation with the swim contractions of the bell shaped body. Given the advanced visual system of box jellyfish and that the pacemaker signal originates in the vicinity of these eyes, it seems logical to assume that the pacemakers are modified by the visual input. Here, the firing frequency and distribution of inter-signal intervals (ISIs) of single pacemakers are examined in the Caribbean box jellyfish, Tripedalia cystophora. It is shown that the absolute ambient light intensity, if kept constant, has no influence on the signal, but if the intensity changes, it has a major impact on both frequency and ISIs. If the intensity suddenly drops there is an increase in firing frequency, and the ISIs become more homogeneously distributed. A rise in intensity, on the other hand, produces a steep decline in the frequency and makes the ISIs highly variable. These electrophysiological data are correlated with behavioral observations from the natural habitat of the medusae.

AB - A major part of the cubozoan central nervous system is situated in the eye-bearing rhopalia. One of the neuronal output channels from the rhopalia carries a swim pacemaker signal, which has a one-to-one relation with the swim contractions of the bell shaped body. Given the advanced visual system of box jellyfish and that the pacemaker signal originates in the vicinity of these eyes, it seems logical to assume that the pacemakers are modified by the visual input. Here, the firing frequency and distribution of inter-signal intervals (ISIs) of single pacemakers are examined in the Caribbean box jellyfish, Tripedalia cystophora. It is shown that the absolute ambient light intensity, if kept constant, has no influence on the signal, but if the intensity changes, it has a major impact on both frequency and ISIs. If the intensity suddenly drops there is an increase in firing frequency, and the ISIs become more homogeneously distributed. A rise in intensity, on the other hand, produces a steep decline in the frequency and makes the ISIs highly variable. These electrophysiological data are correlated with behavioral observations from the natural habitat of the medusae.

U2 - 10.1007/s00359-008-0336-0

DO - 10.1007/s00359-008-0336-0

M3 - Journal article

C2 - 18446348

VL - 194

SP - 641

EP - 651

JO - Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology

JF - Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology

SN - 0340-7594

IS - 7

ER -