Olfactory system salamanders

The demonstration of this behavioural response to a male pheromone signal is significant because of the manner in which the pheromone was delivered. Most other vertebrate examples of reproductive pheromones involve reception via the olfactory system(s). In contrast, D. ocoee females received the pheromone via diffusion through the dorsal skin. We assume that the well developed superficial capillary system of these lungless salamanders is the route by which the male pheromone was transported to whatever target tissue(s) initiated responses that affected female reproductive behaviour. 

The first olfactoiy neuron-specific protein, termed olfactory marker protein was isolated by Frank Margolis in 1972 and was cloned in the 1980s. This 19 kDa cytoplasmatic protein is unique to the mature olfactory system and is found in vertebrates from salamanders to humans (reviewed by Margolis et ah, 1993). 

The terrestrial salamander Plethodonjordani applies courtship pheromone to the female hy ruhhing or slapping his mental gland directly on the female s nares. This way the pheromone can stimulate the vomeronasal organ and accessory olfactory system. Experimental application of mental gland extracts to the nares of females accelerated the time until active courtship started (Houck etal., 1998). 

Correlation of salamander vomeronasal and main olfactory system anatomy with habitat and sex behavioral interpretations. In Chemical Signals in Vertebrates, vol. 6, ed. R. L. Doty and D. Miiller-Schwarze, pp. 403-409. New York Plenum. 

Silver, W.L., Arzt, A.H. Mason, J.R. 1988. A comparison of the discriminatory ability and sensitivity of the trigeminal and olfactory systems to chemical stimuli in the tiger salamander. J. Comp. Physiol., 164A, 55-66. 

Orbach, H.S., Cohen, L.B. Optical monitoring of activity from many areas of the in vitro and in vivo salamander olfactory bulb a new method for studying functional organization in the vertebrate central nervous system. J. Neurosci. 3, 2251-2262 (1983)... 

Figure 2. Schematic diagram of the nasal cavities and forebrain of a salamander, illustrating the central projections of the olfactory and vomeronasal systems in dorsal view. Anterior is toward the top of the figure, and only ipsilateral projections are shown. The medial (A) and lateral (B) olfactory tracts arise from the olfactory bulb. (C) The extra-bulbar ol ctory pathway bypasses the olfactory bulb and projects directly to the anterior preoptic area. (D) The accessory olfactory bulb, which receives input from the vomeronasal organ, projects to the lateral amygdala (la). Other abbreviations apoa = anterior preoptic area dp = dorsal pallium Ip = lateral pallium mp = medial pallium ma = medial amygdala s = septum sir = striatum. Based on descriptions in Hetrick, 1927,1933,1948 Kokoros and Northcutt, 1977 and Schmidt and Roth, 1990.

Mackay-Sim, A., and Kubie, J. L., 1981, The salamander nose A model system for the study for the study of spatial coding of olfactory quality, Chem. Senses 6 249-257. 

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