Effect of anterior ganglia removal on phototaxis in the earthworm mbriscus terrestris)

Abstract

One hundred and sixty earthworms were tested in an escape task. Half had their anterior ganglia removed 24 h prior to testing and half were intact. Half of each group was tested using a 100-W light source as the aversive stimulus, the remainder using a 150-W light source. Each subject was allowed a maximum of 5 min to escape following light onset. All subjects responded faster in the high light intensity condition. Subjects with their anterior ganglia removed escaped faster than controls under the 100-W light intensity condition, indicating the possibility that a specialized temporary lens-like and sensory cell activation follows anterior ganglia removal.