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.
Odorant solutions extracted from horseshoe crab eggs with FSW elicited a significant increase in pallial nerve activity in both knobbed and channeled whelks at a dilution of 103:1, but not at any of the higher dilution ratios (i.
This stimulus elicited a significant increase in pallial nerve activity at a dilution of [10.
Electrophysiological techniques appear suitable for determining odorant solutions that stimulate the pallial nerve in both knobbed and channeled whelks.
The pallial nerve appears to be a sensory nerve that conveys a suite of information to the circumesophogeal ganglion (Laverack and Bailey, 1963).