Much Ado About the First Folio at Boise State

In the afternoon of Sat, Aug 20, the Ron and Linda Yanke Family Research Park building was alive with the First Folio in Idaho Grand Opening Carnival

Effect of lingual voltage clamp on rat NaCl CT response in the absence and presence of Compound 1.

<p>(<b>A</b>) A representative CT response to 100 mM NaCl under open-circuit (0 cc), and at −60 mV and +60 mV and NaCl+Bz response under open-circuit relative to 10 mM KCl rinse (R). (<b>B</b>) Response to 100 mM NaCl +1 mM Compound 1 under open-circuit (0 cc), and at −60 mV and +60 mV and NaCl+Bz+Compound 1 response under open-circuit. (<b>C</b>) Compound 1 (1 mM) added to the rinse (R) gave no tonic CT response. (<b>D</b>) NaCl+Bz gives the smallest open-circuit response, <i>r_o</i>, (0.173±0.009; response at <i>V</i> = 0) and lowest voltage sensitivity (0.0011±0.0002; negative of the slope of the <i>r</i> versus <i>V</i> line, <i>κ</i>). The NaCl curve represents the sum of the Bz-sensitive and the Bz-insensitive responses without Compound 1 (<i>r_o</i> = 0.561±0.029; <i>κ</i> = 0.0031±0.0006) and the NaCl+Compound 1 curve is the sum of the Bz-sensitive and the Bz-insensitive responses in the presence of Compound 1 (<i>r_o</i> = 0.832±0.055; <i>κ</i> = 0.0050±0.0011). For the NaCl line the increase in <i>r_o</i> represents the presence of ENaC and the increased voltage sensitivity indicates the increase in taste cell membrane conductance due to ENaC. The NaCl+Compound 1 line shows the effect of pharmacologically increasing ENaC conductance (greater increase in open-circuit response and voltage sensitivity). (<b>E</b>) The Bz-sensitive part of the NaCl CT response with and without 1 mM Compound 1. Compound 1 increases both the voltage sensitivity (<i>κ</i>) and the open-circuit response (<i>r_o</i>) consistent with modulation of ENaC activity exclusively (cf. Fig. 1A and 1B). The values are mean ± SEM of 3 rats.</p

Relative concentration of NaCl that gives an equivalent open-circuit Bz-sensitive NaCl CT response (<i>r_o</i>) in the absence and presence of ENaC modulators.

<p>Control = Mean control value from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098049#pone-0098049-t003" target="_blank">Table 3</a>.</p>a<p><b><i>r_o</i></b> values are from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098049#pone-0098049-g005" target="_blank">Fig. 5B</a>.</p>b<p><b><i>r_o,</i></b>^c<b><i>r_o</i></b><b>,</b>^d<b><i>r_o</i></b>, and ^e<b><i>r_o</i></b> values are from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098049#pone-0098049-t003" target="_blank">Table 3</a>.</p>b<p><b><i>r_o</i></b> value at 200 mM NaCl is from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098049#pone-0098049-g001" target="_blank">Fig. 1B</a>.</p

Composition of Ringer’s solutions (mM).

a<p>In some experiments the 0 Na⁺ Ringer’s solution contained in addition, 150 µM 8-CPT-cAMP or 3 µM ionomycin.</p><p>The pH of the solutions was adjusted with HCl or NaOH.</p

NaCl and NaCl+Bz dose-response curves.

<p>Open-circuit normalized CT responses to 50, 100, 200, 300 and 500 mM NaCl in the absence and presence of 5 µM Bz. The Bz-sensitive component was obtained as the difference between the CT response in the absence and presence of Bz. The values are mean ± SEM of 3 rats. The curve for the CT response to NaCl+Bz (Bz-insensitive curve) as a function of the NaCl concentration was linear up to 500 mM NaCl and was accordingly fitted to a regression line (R = 0.998) with intercept = −0.011±0.006 and slope = 0.772±0.023. The curve for the Bz-sensitive response was fitted to eq. 3 which describes the saturation of the open-circuit response, <i>r_o</i>, with increasing NaCl concentration (<i>r_m</i> = 1.20±0.11 and <i>K_m</i> = 0.268±0.061 M).</p

Composition of solutions used in CT experiments.

<p>CT responses were monitored under open-circuit conditions and under ±60 mV lingual voltage clamp.</p><p>pH of the solutions containing HEPES or TRIS was adjusted with HCl or NaOH.</p

Effect of lingual voltage clamp on rat NaCl CT response in the absence and presence of Compound 2.

<p>(<b>A</b>) A representative response to 100 mM NaCl under open-circuit (0 cc), and at −60 mV and +60 mV and NaCl+Bz under open-circuit relative to 10 mM KCl rinse (R). (<b>B</b>) Response to 100 mM NaCl +1 mM Compound 2 under open-circuit (0 cc), and at −60 mV and +60 mV and NaCl+Bz+Compound 2 under open-circuit. (<b>C</b>) 1 mM Compound 2 added to the rinse (R) gave no tonic CT response. (<b>D</b>) NaCl+Bz same as in Fig. 2D (<i>r_o</i> = 0.173±0.009; <i>κ</i> = 0.0011±0.0002). The NaCl control curve gave in this case the parameter values: <i>r_o</i> = 0.563±0.007; <i>κ</i> = 0.0030±0.0001 and NaCl+Compound 2 gave: <i>r_o</i> = 0.700±0.010; <i>κ</i> = 0.0043±0.0002. For the NaCl line the increase in <i>r_o</i> represents the presence of ENaC and the increased voltage sensitivity indicates the increase in taste cell membrane conductance due to ENaC. NaCl+Compound 2 line shows the effect of further increasing ENaC conductance (increased <i>r_o</i> and <i>κ</i>). (<b>E</b>) The Bz-sensitive part of the responses to 100 mM NaCl with and without 1 mM Compound 2. The values are mean ± SEM of 3 rats.</p

Voltage sensitivity, <i>κ</i>, is a linear function of the Bz-sensitive part of the open-circuit response, <i>r_o</i>.

<p>(<b>A</b>) Indicates that none of the agonists tested exert their effect on the response by changing the kinetic rate constants of the <i>K_m</i> parameter (see text). Agonist Key: (•) control (no agonist), (□) 1 mM Compound 2, (▪) 20 mM 8-CPT-cAMP, (○) pH_o 10.3, (▵) 1 mM Compound 1, (⋄) 33 mM BAPTA-AM, (∇) 150 µM ionomycin +10 mM Ca²⁺. R = 0.98. Slope of regression line: 0.0059±0.0005, intercept: −0.57×10⁻⁴±3.0×10⁻⁴. (<b>B</b>) The maximum Bz-sensitive NaCl CT response (<i>r_m</i>) is the Na⁺ channel parameter that is regulated by the agonists investigated. Relative to the mean <i>r_m</i> for the NaCl control response (no agonist) the mean <i>r_m</i> of all trials with agonist were either statistically larger or smaller. <i>P</i> values for larger <i>r_m</i> are as follows: Compound 2 (<i>P</i> = 0.0072), pH 10.3 (<i>P</i> = 0.0012), cAMP (<i>P</i> = 0.0021), Compound 1 (<i>P</i> = 0.0012), BAPTA (<i>P</i> = 0.0001). <i>P</i> value for smaller <i>r_m</i>: ionomycin+Ca²⁺ (<i>P</i><0.0001).</p

Effect of lingual voltage clamp on rat NaCl CT response before and after topical lingual application of 8-CPT-cAMP.

<p>(<b>A</b>) Control responses to 300 mM NH₄Cl, 300 mM NaCl, 100 mM NaCl (open-circuit; 0 cc), 100 mM NaCl (−60 mV) and 100 mM NaCl (+60 mV) relative to 10 mM KCl rinse (R). (<b>B</b>) Responses following exposure of rat tongue to 20 mM 8-CPT-cAMP for 30 min. Responses to 100 mM and 300 mM NaCl are enhanced, but the response to 300 mM NH₄Cl is unaffected. (<b>C</b>) The NaCl+Bz and NaCl lines give <i>r_o</i> and <i>κ</i> values characteristic of the Bz-insensitive response and total response respectively. For the Bz-insensitive response line (NaCl+Bz) the parameter values were: <i>r_o</i> = 0.236±0.012 and <i>κ</i> = 0.0016±0.0002, for the control NaCl response <i>r_o</i> = 0.516±0.006 and <i>κ</i> = 0.0032±0.0001, and for the response post-8-CPT-cAMP treatment <i>r_o</i> = 0.865±0.025 and <i>κ</i> = 0.0052±0.0005. (<b>D</b>) Bz-sensitive NaCl CT response versus voltage under control conditions and post-8-CPT-cAMP exposure. The values are mean ± SEM of 3 rats.</p

Effect of 8-CPT-cAMP on ENaC-dependent NaCl CT responses in 19–23 day old rats.

<p><b>(A)</b> Mean normalized tonic CT response under open-circuit conditions (filled squares) to NaCl (<i>r</i>_<i>o</i>(0)) at zero 8-CPT-cAMP (<i>N</i> = 12–18). Since <i>r</i>_<i>o</i>(0) = <i>r</i>_<i>aso</i>(0) + <i>r</i>_<i>aio</i>(0), the solid line through the data points is the sum of the regression curves for <i>r</i>_<i>aso</i>(0) and <i>r</i>_<i>aio</i>(0). Mean normalized tonic CT response under open-circuit conditions (open circles) to NaCl + CPC (<i>r</i>_<i>aso</i>(0)) at zero 8-CPT-cAMP (<i>N</i> = 10–13). Curve (long dashes) is the regression curve. CT response under open-circuit conditions (closed triangles) to NaCl + CPC + Bz at zero 8-CPT-cAMP (<i>N</i> = 3). Curve (short dashes) is the linear regression line. <b>(B)</b> Mean ENaC-dependent part of the CT response as a function of NaCl concentration under open circuit conditions in 19–23 day old rats before (r_aso(0); open circles) and following exposure to 20 mM CPT-cAMP (r_aso(20); filled circles). The curves are the least squares fits to the data using <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0171335#pone.0171335.e001" target="_blank">Eq 1</a> with <i>φ</i> = 0. The dotted line represents the pre-cAMP control curve and the solid curve represents the post 20 mM 8-CPT-cAMP curve. Each NaCl solution contained 2 mM CPC to block the Bz-insensitive part of the response. For r_aso(0), <i>N</i> = 10 (0.1 M NaCl), <i>N</i> = 13 (0.3 M NaCl) and <i>N</i> = 10 (0.5 M NaCl). For r_aso(20), <i>N</i> = 5 (0.1 M NaCl), <i>N</i> = 9 (0.3 M NaCl) and <i>N</i> = 10 (0.5 M NaCl).</p