[ATP-activated single ion channel and its properties in cerebral cortical neurons of neonatal rat].
In the present study, single channel currents were recorded from single neurons dissociated from the cerebral cortex of neonatal SD rat by the cell-attached and inside- out modes of patch clamp technique. ATP-activated channels with a conductance of 32 pS were often recorded and permeable to Na+, K+ and Cs+, but not to Cl-. Most of open time distribution histograms were fitted by two exponential components and few by one, whereas closed time distribution histograms were fitted by two exponential components. Both mean open time and open probability were independent of membrane potential, but the latter increased with increasing ATP concentration. The channel activity was recorded only in the presence of pipette solution containing ATP, and its conductance and open probability were not affected by ACh N-receptor antagonist hexamethonium and mecamylamine. It is suggested that ATP-activated ion channels probably exist in the cerebral cortical neurons of neonatal rat.
Ren
J
J
Department of Physiology, Sun Yat-Sen University of Medical Sciences, Guangzhou.
Chen
Z H
ZH
Chen
P X
PX
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism*; D005260:Female; D007473:Ion Channels / Q000502:physiology; D008297:Male; D008564:Membrane Potentials; D009474:Neurons / Q000378:metabolism; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015222:Sodium Channels / Q000502:physiology*
D007473:Ion Channels; D015221:Potassium Channels; D015222:Sodium Channels; D000255:Adenosine Triphosphate