scholarly journals Single channel currents activated by gamma-aminobutyric acid, muscimol, and (-)-pentobarbital in cultured mouse spinal neurons

1982 ◽  
Vol 2 (7) ◽  
pp. 889-894 ◽  
Author(s):  
MB Jackson ◽  
H Lecar ◽  
DA Mathers ◽  
JL Barker
1994 ◽  
Vol 71 (6) ◽  
pp. 2570-2575 ◽  
Author(s):  
L. S. Premkumar ◽  
P. W. Gage

1. Single-channel currents were recorded in cell-attached patches on cultured hippocampal neurons in response to gamma-aminobutyric acid-B (GABAB) agonists or serotonin applied to the cell surface outside the patch area. 2. The channels activated by GABAB agonists and serotonin were potassium selective but had a different conductance and kinetic behavior. Channels activated by GABAB agonists had a higher conductance, longer open-time, and longer burst-length than channels activated by serotonin. 3. The kinetic behavior of channels activated by GABAB agonists varied with potential whereas channels activated by serotonin did not show voltage-dependent changes in kinetics. 4. In a few cell-attached patches, both types of channel were activated when the cell was exposed to GABA together with serotonin. 5. It was concluded that GABAB agonists and serotonin activate different potassium channels in the soma of cultured hippocampal neurons.


1991 ◽  
Vol 161 (1) ◽  
pp. 455-468
Author(s):  
F. ZUFALL ◽  
H. HATT ◽  
T. A. KEIL

Single-channel patch-clamp techniques were used to identify and characterize a Ca2+-activated nonspecific cation channel (CAN channel) on insect olfactory receptor neurones (ORNs) from antennae of male Antheraea polyphemus. The CAN channel was found both in acutely isolated ORNs from developing pupae and in membrane vesicles from mature ORNs that presumably originated from inner dendritic segments. Amplitude histograms of the CAN single-channel currents presented well-defined peaks corresponding to at least four channel substates each having a conductance of about 16 pS. Simultaneous gating of the substates was achieved by intracellular Ca2+ with an EC50 value of about 80 nmoll−1. Activity of the CAN channel could be blocked by application of amiloride (IC50 <100nmoll−1). Moreover, in the presence of 1μmoll−1 Ca2+, opening of the CAN channel was totally suppressed by 10 μmoll−1 cyclic GMP, whereas ATP (1 mmol l−1) was without effect. We suggest that the CAN channel plays a specific role in modulation of cell excitability and in shaping the voltage response of ORNs.


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