Optical measurement of action potential activity in invertebrate ganglia.
With a voltage-sensitive dye and an array of silicon photodiodes we monitored the action potential activity of a large fraction of the cells in the Aplysia abdominal ganglion during the gill-withdrawal reflex. This capability allowed a direct determination of the spread of sensory information within the 1,000 neurons of the ganglion. Surprisingly, approximately 30% of the neurons are activated by a light touch to a small area of siphon skin. It is likely that many other neurons also receive large synaptic potentials, either excitatory or inhibitory, and thus even a very mild and restricted stimulus will have widely distributed effects. It seems to us that these results will force a more pessimistic view of the present understanding of the neuronal basis of apparently simple behaviors.
Wu
J Y
JY
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510.
Falk
C X
CX
Cohen
L
L
Tsau
Y
Y
Zecevic
D
D
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001048:Aplysia / Q000502:physiology*; D004396:Coloring Agents; D004435:Eating / Q000502:physiology; D017952:Ganglia, Invertebrate / Q000166:cytology / Q000502:physiology*; D005880:Gills / Q000502:physiology; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D008974:Mollusca / Q000502:physiology*; D010775:Photic Stimulation; D012018:Reflex / Q000502:physiology
D004396:Coloring Agents