[Abstract Title]. - Society for Neuroscience

complex rectification of Kir4.1 channels. Because of differences in kinetics, both blocks could be
distinguished and are observed as two curvatures in the I/V relationship of Kir4.1 conductance.
Under non-symmetrical conditions which are close to physiological (3 mM K + out -147 mM
Na + out/ 3 mM Na + in-147 mM K + in), both types of block were found, however, the degree of SP
block was weaker than in symmetrical conditions and the contribution of Na + block to
rectification was more pronounced by SP.
These data suggest that redistribution of K + and Na + gradients around the glial membrane during
neuronal excitation can affect Kir4.1 rectification. Therefore, glial cells surrounding GABA or
glutamate synapses may function differently in respect to Kir4.1 properties. Linear I/V curves
are observed for Kir4.1 only in absence of both Na + and SP 4+ . Moreover, Na + accumulation
stabilizing Kir4.1 rectification is inherent to support glial function.
Disclosures: Y.V. Kucheryavykh, None; S.M. Antonov, None; Y.M. Shuba, None; L.Y.
Kucheryavykh, None; M. Inyushin, None; H. Kurata, None; C.G. Nichols, None; M.J.
Eaton, None; S.N. Skatchkov, None.
Poster
234. A-Type Potassium Channels
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 234.22/C46
Topic: B.04.c. Potassium channels: Physiology
Support: RFBR 08-04-00423-a
BMB+F (IZKF, 01KS 9504 project C5)
NIH-NINDS and NCRR SNRP-U54 NS039408
DFG Ve-187/1-2
NIH-RCMI G12RR03035
Title: Intracellular sodium block of Kir2.1 channels
Authors: *S. M. ANTONOV 1 , Y. V. KUCHERYAVYKH 2 , Y. M. SHUBA 4 , R. W. VEH 5 , A.
REICHENBACH 6 , H. KURATA 7 , C. G. NICHOLS 7 , M. J. EATON 2 , S. N. SKATCHKOV 3 ;
1 Sechenov Inst. of Evolutionary Physiol. and Biochem. RAS, St-Petersburg, Russian Federation;
2 Biochem., 3 Biochem. and Physiol., Univ. Central del Caribe, Bayamon, PR; 4 Intl. Ctr. of Mol.
Physiology, NASU, Kiev, Ukraine; 5 Inst. Integrated Anat., Charite, Berlin, Germany; 6 Inst. of