TY - JOUR
T1 - Effects of medazepam on voltage-gated ion currents of cultured chick sensory neurons
AU - Yang, J.
AU - Johansen, J.
AU - Kleinhaus, A. L.
AU - DeLorenzo, R. J.
AU - Zorumski, C. F.
N1 - Funding Information:
This work was in part supported by McDonnell Foundation Fellowships through the Washington University Center for Cellular and Molecular Neurobiology to J.Y., Center for Studies of Higher Brain Function to C.F.Z., and grant NS06208-21 to A.L.K. We thank Drs. W. Taft, J. Nerbonne and M. Apkon for reading an earlier version of the manuscript and Dr. G.D. Fischbach for the use of his laboratory.
PY - 1987/11/17
Y1 - 1987/11/17
N2 - The effects of the benzodiazepine, medazepam, were investigated in current and voltage-clamped cultured chick dorsal root ganglion neurons. Under current clamp, micromolar concentrations initially elevated the action potential threshold and blocked both the sodium and calcium components of the spike. In voltage clamp, low (I(Ca, T)) and high (I(CA, N/L)) threshold calcium, sodium (I(Na)) and the delayed rectifier potassium (I(K)) currents were isolated by the use of appropriate solutions and voltage command protocols. Medazepam depressed both subtypes of I(Ca) equally well with calculated half-maximal depression at 77 μM. At a fixed concentration of 200 μM, medazepam depressed I(Na) (70 ± 9%) and I(K) (73 ± 6%) to a degree comparable to I(Ca) (75 ± 3%). The results show that benzodiazepines can modulate the activity of several voltage-gated ion currents in chick dorsal root ganglion neurons.
AB - The effects of the benzodiazepine, medazepam, were investigated in current and voltage-clamped cultured chick dorsal root ganglion neurons. Under current clamp, micromolar concentrations initially elevated the action potential threshold and blocked both the sodium and calcium components of the spike. In voltage clamp, low (I(Ca, T)) and high (I(CA, N/L)) threshold calcium, sodium (I(Na)) and the delayed rectifier potassium (I(K)) currents were isolated by the use of appropriate solutions and voltage command protocols. Medazepam depressed both subtypes of I(Ca) equally well with calculated half-maximal depression at 77 μM. At a fixed concentration of 200 μM, medazepam depressed I(Na) (70 ± 9%) and I(K) (73 ± 6%) to a degree comparable to I(Ca) (75 ± 3%). The results show that benzodiazepines can modulate the activity of several voltage-gated ion currents in chick dorsal root ganglion neurons.
KW - Benzodiazepine
KW - Dorsal root ganglion cells
KW - Voltage clamp
KW - Voltage-gated channels
UR - http://www.scopus.com/inward/record.url?scp=0023637090&partnerID=8YFLogxK
U2 - 10.1016/0014-2999(87)90461-4
DO - 10.1016/0014-2999(87)90461-4
M3 - Article
C2 - 2446893
AN - SCOPUS:0023637090
SN - 0014-2999
VL - 143
SP - 373
EP - 381
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
IS - 3
ER -