Ca2+ currents of fast blue-labeled superior cervical ganglion neurons.
To investigate if Ca2+ currents of acutely isolated superior cervical ganglion (SCG) neurons are altered after dye labeling or ultraviolet (UV) exposure, SCG neurons were labeled by multiple injections of 2% fast blue (FB) (5-microliters total) into the submaxillary gland. Ca2+ currents of both labeled and unlabeled neurons were significantly depressed by 2-min exposure to UV, compared to labeled and unlabeled neurons not exposed to UV. The I-V curve of labeled neurons was shifted hyperpolarized after UV exposure. Tail-current activation curves of both labeled and unlabeled neurons were fitted to a double Boltzmann equation. In labeled neurons, 2-min exposure to UV produced a significant reduction of the amplitude of the more depolarized component as well as a hyperpolarizing shift of the half activation potential of both components of the activation curve. However, the short time (< 10 s) required to identify a target-specific neuron had no significant effect on the biophysical properties of Ca2+ currents of FB-labeled SCG neurons. Thus, use of this label in combination with the patch-clamp technique comprises a powerful approach to study membrane currents of target-specific neurons.
D000578:Amidines; D000818:Animals; D001370:Axonal Transport; D002118:Calcium / Q000502:physiology*; D002478:Cells, Cultured; D005456:Fluorescent Dyes; D005728:Ganglia, Sympathetic / Q000166:cytology / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology* / Q000528:radiation effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D014466:Ultraviolet Rays
D000578:Amidines; D005456:Fluorescent Dyes; C031455:diamidino compound 253-50; D002118:Calcium