Ca(2+)-dependent chloride conductance in Necturus taste cells.

Area of Science:

• Neuroscience
• Sensory Biology
• Physiology

Background:

• Taste perception involves complex cellular mechanisms.
• Ion channels play a crucial role in taste cell signaling.
• Understanding calcium-dependent conductances is key to elucidating taste transduction.

Purpose of the Study:

• To investigate the presence and location of calcium-dependent chloride conductance in Necturus maculosus taste cells.
• To characterize the role of this conductance in taste cell electrical activity.

Main Methods:

• Dissection of lingual epithelium from Necturus maculosus.
• Ussing chamber technique for isolating and recording from individual taste cells.
• Intracellular microelectrode recordings to measure action potentials and conductances.
• Pharmacological manipulation (e.g., TEA) to isolate specific ion channel activities.

Main Results:

• A significant Ca(2+)-dependent chloride conductance was found in Necturus taste cells.
• This conductance contributes to prolonged depolarization (afterdepolarization) following action potentials.
• Calcium-dependent conductance channels are present on both apical and basolateral membranes.
• Other Ca(2+)-dependent channels (K+, nonselective cation) may also contribute to afterpotentials.

Conclusions:

• Ca(2+)-dependent chloride channels are a component of taste cell signaling in Necturus.
• These channels may be involved in the cellular discrimination of chloride salts.
• The findings contribute to understanding the mechanisms shaping taste receptor cell responses.