62 DON TUCKER 



presented. Thus it is now evident that movement of the mucosa relative 

 to the tip of the electrode occurred. 



Trigeminal activation is often accompanied by profuse flow of nasal 

 secretions. An increase in the rate of mucous secretion from the olfactory 

 mucosa and in the rate of flow of mucus over it would conceivably reduce 

 the accessibility of odorant molecules to the receptors. 



RABBIT 



Although we have invested much more work in studying the rabbit, the 

 results are not so extensive for this animal as for the tortoise. The anes- 

 thetized rabbit seems to be a comparatively poor preparation for recording 

 from the primary olfactory nerve. We believe that in large part this is 



M ^ ■ 



K v___^'_v_V_ 



INTEGRATED RESPONSE OF PRIMARY OLFACTORY NERVE TWIG TO AMYL ACETATE 

 CONCENTRATIONS INDICATED IN TERMS OF VAPOR SATURATION AT 20* C 



RABBIT RESPIRING UNDER DEEP URETHANE ANESTHESIA 



i 



Fig. 16. Rabbit olfactory response for amyl acetate concentration series in 1/4 



log steps. 



because of the greater geometrical complexity of the nasal anatomy. 

 Hopefully, Dr. Moulton's (this Symposium) work with implanted electrodes 

 will reveal the nature of some of the diff'erences we can expect to find for 

 rabbits in the conscious and anesthetized states. 



Olfactory Receptors 



Most olfactory twigs were picked up from the dorsomedial aspect of the 

 nerve at the level of the cribriform plate. These twigs project to areas in 

 the mucosa high up on the septal wall and over onto the lateral arch. 

 Fortunately, this seems to be one of the most accessible portions of the 

 organ for olfactory stimuli. 



Olfactory responses recorded during free respiration for a concentration 



