sic:^c 



Figure 10-2. Diagram of Stimulation-Recording 

 Chamber ("Olfactometer"). 



NOTE: Stimulus is injected with a syringe (A) into a seawater flow (B) over 

 the dissected lobster antennule. The antennule is perfused through a micro- 

 pipette with oxygenated lobster saline (C) which exits the antennule into a 

 bath of saline (D). To make recordings, one small bundle of nerve fibers is 

 lifted from the saline bath into the air with a platinum hook electrode (E). 

 Seawater and saline baths are separated by a Sylgard cork, through which the 

 antennule passes. 



Neurophysiology 



Electrophysiological data were obtained from chemoreceptors of oil-exposed 

 and normal lobsters, some of which had been observed behaviorally. This 

 permits a comparison between the neural chemosensory input the animal 

 received, and the resultant behavior after processing through higher nerve 

 centers. Such a comparison is a necessary step in determining whether oil 

 interferes with behavior through chemoreception. 



To measure neurophysiological activity, the lateral flagellum of the 

 antennule of a lobster was removed and placed in fresh seawater. The cut 

 proximal end was inserted through a Sylgard cork. Three to four cuticular rings 

 were removed. The distal tip was cut and the antennule placed in a lobster 

 sahne bath in the stimulation-recording chamber (Figure 10-2). A micropipette 

 was inserted snugly into the distal tip, and perfusion with oxygenated lobster 



126 



