The central ganglia of the sea slug, Tritonia diomedea
Photographed by Steve Hardy, Autumn 2002

As a research apprentice at the UW Friday Harbor Labs in Autumn 2002, Neurobiology major Steve Hardy studied the expression of immediate early genes (IEGs) in the central nervous system of the sea slug, Tritonia diomedea.

Steve says, "the purpose of this study is to determine if cellular activation of T. diomedea can be determined by the detection of the protein encoded by IEG c-fos. Presently, no such cell activity-marker exists for T. diomedea. This would be an important tool to localize brain cells that control behaviors such as swim-escape or geomagnetic orientation/navigation. With a reliable marker for cell activation, more systematic inquiry into the nervous control of behavior can be performed."

Immunoflourescent TH labeling in T. diomedea larvae
Photographed by Marcel Tam and Hoang Nhan, Autumn 2002

In Autumn 2002 at the UW Friday Harbor Laboratories, Neurobiology majors Marcel Tam and Hoang Nhan studied the presence of two neurotransmitters, TPep and Dopamine, in Tritonia diomedia larvae and their effects on larval ciliary activity.

Everyone walks using their legs, and so do sea slug babies, only they use their legs to swim in the sea, and for the ones we raised and nurtured, in our jars. People think that an adult sea slug's legs, called "cilia," are under direct control of 2 chemicals: TPep and TH. In sea slug babies, we keenly observed that some of the cells at the base of the Mickey Mouse's ear-like lobes-scientifically called "velar lobes"-are swelled with those chemicals. However, our babies don't seem to use those chemicals to swim as we thought they would. So, they are born with the drugs but we don't know what they take them for. The answer lies in future investigations that have yet to be conducted.

Electrophysiological recording of Pd Nerve 3 in the CNS of T. diomedea following magnetic stimulation
Recorded by Sam Han, Autumn 2002

Neurobiology major Sam Han spent Autumn Quarter 2002 at the UW Friday Harbor Labs searching for sensory input to magneto-sensitive neurons in Tritonia diomedea. The neural activity of Pd nerves 2 and 3 were recorded extracellularly while the ambient magnetic field was rotated. These nerves have been shown to innervate the epithelial layer of the foot of the Tritonia. Upon 100 seconds of the stimulation, the Pd nerve 3 showed an increase in neural activity while Pd nerve 2 showed no significant change. This evidence suggested that the central nervous system, where the Pd 5 lies, is responsible for the 6 – 16 minute delayed response to magnetic field.