Fluorescence imaging of local membrane electric fields during the excitation of single neurons in culture.
AUTOR(ES)
Gogan, P
RESUMO
The spatial distribution of depolarized patches of membrane during the excitation of single neurons in culture has been recorded with a high spatial resolution (1 micron2/pixel) imaging system based on a liquid-nitrogen-cooled astronomical camera mounted on an inverted microscope. Images were captured from rat nodose neurons stained with the voltage-sensitive dye RH237. Conventional intracellular microelectrode recordings were made in synchrony with the images. During an action potential the fluorescence changes occurred in localized, unevenly distributed membrane areas, which formed clusters of depolarized sites of different sizes and intensities. When fast conductances were blocked by the addition of tetrodotoxin, a reduction in the number and the intensities of the depolarized sites was observed. The blockade by tetrodotoxin of voltage-clamped neurons also reduced the number of depolarized sites, although the same depolarizing voltage step was applied. Similarly, when a voltage-clamped neuron was depolarized by a constant-amplitude voltage step, the number of depolarized sites varied according to the degree of activation of the voltage-sensitive channels, which was modified by changing the holding potential. These results suggest that the spatial patterns of depolarization observed during excitation are related to the operations of ionic channels in the membrane.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1236254Documentos Relacionados
- Release of neuropeptides during intracellular stimulation of single identified Aplysia neurons in culture.
- Local influence of substrate molecules in determining distinctive growth patterns of identified neurons in culture.
- Laser-stimulated fluorescence of submicrometer regions within single mitochondria of rhodamine-treated myocardial cells in culture.
- Neurosteroid regulation of GABAA receptor single-channel kinetic properties of mouse spinal cord neurons in culture.
- Biosynthesis of immunoreactive somatostatin by hypothalamic neurons in culture.