C. Balachandran et Mr. Bennett, ATP-ACTIVATED CATIONIC AND ANIONIC CONDUCTANCES IN CULTURED RAT HIPPOCAMPAL-NEURONS, Neuroscience letters, 204(1-2), 1996, pp. 73-76
The effects of adenosine 5'-triphosphate (ATP) on voltage-clamped and
dissociated rat hippocampal neurons was investigated. Over 30% of neur
ons possessed ATP-activated inward currents at a holding potential of
-70 mV. The ED(50) for these currents was 150 mu M. At this concentrat
ion they were blocked by suramin (1 mM), indicating the involvement of
P2-purinoceptors. The P2 purinoceptor agonist potency was 2-methylthi
o ATP > ATP > ADP > alpha,beta-methylene ATP, thus identifying these p
urinoceptors as belonging to the P2x subclass. The reversal potential
for the ATP-activated currents was -45 +/- 8 mV. Ion substitution expe
riments showed that the permeability ratio for K+/Na+/Cs+/Cl-, was 18:
3:2:1, according to the Goldman-Hodgkin-Katz equation, so that ATP act
ivates cationic and anionic conductances in hippocampal neurons.