Journal of Neuroscience, Vol 9, 3681-3689, Copyright © 1989 by Society for Neuroscience
Hundreds of neurons in the Aplysia abdominal ganglion are active during the gill-withdrawal reflex
D Zecevic, JY Wu, LB Cohen, JA London, HP Hopp and CX Falk
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510.
A combination of optical and electrode recording methods was used to obtain
an overview of the neuron activity in the Aplysia abdominal ganglion in
response to a light touch to the siphon skin. Spike activity was detected
in up to 150 different neurons. Habituation and sensitization of the
gill-withdrawal reflex was accompanied by large changes in the number of
activated neurons. It is likely that these recordings are incomplete; the
actual number of activated neurons is estimated to be about 300 in the
acutely sensitized preparation. While we presume that not all 300 of these
neurons are involved in the gill- withdrawal reflex, the number of neurons
is so large that it may be difficult to determine the role of each
activated neuron with presently available experimental tools.