Journal of Neuroscience, Vol 5, 128-135, Copyright © 1985 by Society for Neuroscience
Electrophysiological properties of identified cells in the in vitro olfactory epithelium of the tiger salamander
LM Masukawa, B Hedlund and GM Shepherd
An in vitro preparation of the salamander olfactory epithelium has been
developed for electrophysiological analysis. Intracellular measurements of
membrane properties of the main epithelial cell types have been carried
out, combined with Lucifer Yellow injections. The most prevalent type of
cell had a high resting membrane potential and relatively low input
resistance. This cell never discharged impulses, either spontaneously or to
injected current. Lucifer Yellow injections identified this cell type as a
supporting cell. A less frequent type had a medium resting potential and a
very high input resistance. This type always discharged impulses in
response to injected depolarizing current. Lucifer Yellow injections
identified this cell type as an olfactory receptor neuron. The least
frequent type had a medium resting potential and a high input resistance.
It never generated action potentials. This nonspiking type was tentatively
identified as an immature receptor neuron in the process of differentiating
from basal stem cells in the epithelium. These are the first results to
document physiological properties for the main cell types and morphological
identification of two of the types in the same preparation of the olfactory
epithelium. Our results support previous suggestions regarding the
glial-like properties of the supporting cells. The membrane properties of
the receptor neurons appear to be well suited for mediating the olfactory
sensory response of these cells.