Abstract
The effect of Zn2+ on a voltage-dependent, transient potassium current (I(A)) in acutely dissociated neurons from the suprachiasmatic nucleus was studied with the whole-cell patch-clamp technique. At micromolar concentrations, Zn2+ markedly potentiated I(A) activated from a holding potential of -60 mV, which is the resting potential of these neurons. This potentiation occurred at a Zn2+ concentration as low as 2 μM and increased with higher Zn2+ concentrations. The Zn2+ action appears to arise from a shift in the steady-state inactivation of I(A) to more positive voltages. At 30 μM, Zn2+ shifted the half-inactivation voltage by +20 mV (from -80 mV to -60 mV), and 200 μM Zn2+ shifted this voltage by +45 mV (from -80 mV to -35 mV). Histochemically, we have also observed Zn2+ staining throughout the suprachiasmatic nucleus; the staining is particularly intense in the ventrolateral region of the nucleus, which receives the major fiber inputs. Our findings suggest that Zn2+, presumably synaptically released, may modulate the electrical activity of suprachiasmatic nucleus neurons through I(A). Because vesicular Zn2+ is fairly widespread in the central nervous system, it is conceivable that this kind of Zn2+ modulation on I(A), and possibly on other voltage-activated currents, exists elsewhere in the brain.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 11806-11810 |
| Number of pages | 5 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 90 |
| Issue number | 24 |
| DOIs | |
| State | Published - Dec 29 1993 |
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Cite this
Zinc modulation of a transient potassium current and histochemical localization of the metal in neurons of the suprachiasmatic nucleus. / Huang, R. C.; Peng, Y. W.; Yau, K. W.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 90, No. 24, 29.12.1993, p. 11806-11810.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Zinc modulation of a transient potassium current and histochemical localization of the metal in neurons of the suprachiasmatic nucleus
AU - Huang, R. C.
AU - Peng, Y. W.
AU - Yau, K. W.
PY - 1993/12/29
Y1 - 1993/12/29
N2 - The effect of Zn2+ on a voltage-dependent, transient potassium current (I(A)) in acutely dissociated neurons from the suprachiasmatic nucleus was studied with the whole-cell patch-clamp technique. At micromolar concentrations, Zn2+ markedly potentiated I(A) activated from a holding potential of -60 mV, which is the resting potential of these neurons. This potentiation occurred at a Zn2+ concentration as low as 2 μM and increased with higher Zn2+ concentrations. The Zn2+ action appears to arise from a shift in the steady-state inactivation of I(A) to more positive voltages. At 30 μM, Zn2+ shifted the half-inactivation voltage by +20 mV (from -80 mV to -60 mV), and 200 μM Zn2+ shifted this voltage by +45 mV (from -80 mV to -35 mV). Histochemically, we have also observed Zn2+ staining throughout the suprachiasmatic nucleus; the staining is particularly intense in the ventrolateral region of the nucleus, which receives the major fiber inputs. Our findings suggest that Zn2+, presumably synaptically released, may modulate the electrical activity of suprachiasmatic nucleus neurons through I(A). Because vesicular Zn2+ is fairly widespread in the central nervous system, it is conceivable that this kind of Zn2+ modulation on I(A), and possibly on other voltage-activated currents, exists elsewhere in the brain.
AB - The effect of Zn2+ on a voltage-dependent, transient potassium current (I(A)) in acutely dissociated neurons from the suprachiasmatic nucleus was studied with the whole-cell patch-clamp technique. At micromolar concentrations, Zn2+ markedly potentiated I(A) activated from a holding potential of -60 mV, which is the resting potential of these neurons. This potentiation occurred at a Zn2+ concentration as low as 2 μM and increased with higher Zn2+ concentrations. The Zn2+ action appears to arise from a shift in the steady-state inactivation of I(A) to more positive voltages. At 30 μM, Zn2+ shifted the half-inactivation voltage by +20 mV (from -80 mV to -60 mV), and 200 μM Zn2+ shifted this voltage by +45 mV (from -80 mV to -35 mV). Histochemically, we have also observed Zn2+ staining throughout the suprachiasmatic nucleus; the staining is particularly intense in the ventrolateral region of the nucleus, which receives the major fiber inputs. Our findings suggest that Zn2+, presumably synaptically released, may modulate the electrical activity of suprachiasmatic nucleus neurons through I(A). Because vesicular Zn2+ is fairly widespread in the central nervous system, it is conceivable that this kind of Zn2+ modulation on I(A), and possibly on other voltage-activated currents, exists elsewhere in the brain.
UR - http://www.scopus.com/inward/record.url?scp=0027136228&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027136228&partnerID=8YFLogxK
U2 - 10.1073/pnas.90.24.11806
DO - 10.1073/pnas.90.24.11806
M3 - Article
C2 - 8265630
AN - SCOPUS:0027136228
VL - 90
SP - 11806
EP - 11810
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 24
ER -