کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6269852 1295162 2011 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
In vivo simultaneous intra- and extracellular potassium recordings using a micro-optrode
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
In vivo simultaneous intra- and extracellular potassium recordings using a micro-optrode
چکیده انگلیسی

This technique proposes a new approach to correlate intra- and extracellular variations of the ionic concentrations in vivo by means of tapered optical waveguides coupled to standard electrophysiological electrodes to monitor in vivo simultaneously the intracellular and extracellular K+ concentration as well as the neighboring field potential. The optical fibers were tapered to a final diameter of approximately 10 μm and were used to guide the excitation light deep into the tissue and to collect the fluorescence emanating from the intracellular milieu. This fiber was coupled to a double barrel ion-sensitive electrode forming a micro-optrode with a final diameter around 15 μm. The method was successfully used to record the intracellular K+ evolution with the fluorescent indicator PBFI during three states: normal sleep-like patterns, paroxysmal seizures, and coma. While we could not disclose any phasic fluctuations of the intracellular K+ during normal sleep patterns, they were clearly present during seizures and coma. In the majority of cases (58%), paroxysmal discharges were associated with positive variations of the intracellular fluorescence of 62 ± 5% corresponding to extracellular K+ increases of 2.04 ± 0.4 mM. In the remaining cases (42%) intracellular K+ dropped by 44.4 ± 12% for an extracellular K+ increase of 2.62 ± 0.47 mM. We suggest that this differential behavior might reflect different cellular populations (glia vs. neurons, respectively). Comatose states were accompanied by an extracellular drop of K+ of 1.31 ± 0.13 mM, which was reflected, in all cases, by an intracellular K+ increase of 39 ± 4%.

Research highlights▶ New technique allowing simultaneous recording of extra- and intracellular K+ concentrations in vivo. ▶ Electrode based on composed electrical (electrophysiology) and optical probes. ▶ The method suggests opposite behaviors of neurons and glia with respect to the transfer of K+ across membranes. ▶ Technique successfully applied during normal sleep patterns and pathological (epileptic and comatose) states.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Neuroscience Methods - Volume 194, Issue 2, 15 January 2011, Pages 206-217
نویسندگان
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