Possible Interaction: Ethanol and Tetrodotoxin

“Brief superfusion of ethanol (64, 190, and 560 mmol/L) dose-dependently and reversibly suppressed the spontaneous firing of the neurons in the TMN; when synaptic transmission was blocked by tetrodotoxin (1 μmol/L), ethanol caused hyperpolarization of the membrane potential.”

“In the case of TTXr channels, ethanol decreased their selectivity in relation to Na ions and altered the sequence of ion selectivity of these channels for different cations from row X to row XI of the Eisenman selectivity classification.”

“ Ethanol was shown to decrease the reversal potential of tetrodotoxin-resistant (TTXr) and TTX-sensitive channels in short-term culture of the dorsal root ganglion cells.”

“The ethanol led to alterations in ionic selectivity of the TTXr channels (its shifting from the X-th Eisenmann selectivity sequence to the XI-th one).”

“ Ethanol also depressed glutamate-evoked responses in the presence of tetrodotoxin (300 nM), showing that its actions are postsynaptic.”

“At a holding potential of −80 mV ethanol (200 mM) decreased peak tetrodotoxin‐resistant (TTX‐R) and tetrodotoxin‐sensitive (TTX‐S) INa by 19.0% ± 2.7 (mean ± SEM) and 8.5% ± 2.2, respectively.”

“ Ethanol thus selectively induced both voltage‐independent and voltage‐dependent block of TTX‐R INa in DRGn.”

“Finally, contractile responses to ethanol and APSA were completely blocked by atropine (0.1 microM) and tetrodotoxin (0.1 microM).(ABSTRACT TRUNCATED AT 250 WORDS)”

“ Ethanol augmented the hyperpolarization that followed repetitive firing or that followed the eliciting of calcium spikes in the presence of tetrodotoxin , but not the rapid afterhyperpolarization in calcium-free medium.”