Turbellarian taxonomic database

Abstract / Notes

"The formaldeyde-glutaraldehyde-sucrose (FGS) method for in situ localization of catecholamines has been
applied to the nervous system of the marine polyclad flatworm Notoplana acticola. This histochemical
fluorescence technique revealed the presence of a small population of fluorescent cells within the brain. The
number and positions of these neurons were constant in animals of the same size, but varied with the size of
the worm. The brains of small animals (8 mm in length) were found to contain 20 fluorescent cells, whereas the
largest animals studied (30 mm in length) were found to have 28 such cells. Various intermediate cell numbers
were found in animals between these two sizes. The origin of the newly added fluorescent cells is uncertain.
Peripheral fluorescence was found in association with the tentacular ocelli (eyespots) and interneurons within
the ventral submuscular nerve plexus. The fluorescent spectrum from these cells measured in situ had a
.lambda.max of 526 nm. Treatment with HCl shifts this peak to 530 nm. L-dopamine fluoresces with a similar
peak emission before HCl treatment (525.5 nm) and shifts to the appropriate longer wavelength (530 nm)
following acidification. This strongly suggests that the fluorescent substance in the neurons is dopaminergic
in nature."

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