To identify other baits, the activity in the pallial nerve of whelks was determined during exposure of the osphradium to odorant solutions prepared from horseshoe crab eggs, horseshoe crab hemolymph, and hard clam (Mercenaria mercenaria) tissue.
Activity in the pallial nerve was recorded while odorant solutions were applied directly to the osphradium.
Quantifying activity in the pallial nerve in response to odorant solutions required that the whelk be removed from its shell, the pallial nerves exposed, and the osphradium isolated.
To record activity in the pallial nerve associated with the exposure of the osphradium to odorant solutions, the nerve was cut and the afferent end was drawn into a suction electrode (Fig.
An additional 3 minutes were allowed between odor trials to ensure that the odorant solution was flushed from the osphradium chamber and that the activity in the pallial nerve had returned to prestimulus levels (Fig.
The pallial nerve typically showed spontaneous activity, although nerve activity clearly increased as the concentration of a detectable odorant solution in the osphradium chamber reached maximal concentration (Fig.
Autoradiographic experiments indicate that optic nerves from separate eyes join the circumpallial nerve, cross the mantle via one of several pallial nerves, and finally make synaptic contact with second-order interneurons on the cortical surface of one of the two lateral lobes of the PVG (Spagnolia and Wilkens, 1983).
4E) and was the only Goc protein that appeared to be expressed at high levels by the pallial nerves entering the lateral lobes (Fig.
o] in the pallial nerves entering the lateral lobes or in the axons of the photoreceptors of the distal retina.
q] expression, we were able to trace the axons of the proximal photoreceptors as they exited the eyes and visualize the pallial nerves as they entered the lateral lobes of the PVG.