phenomenon can be measured by Calcium ion sensitive fluorescent dye. Further analyses showed that these Calcium ion oscillations are sensitive to MK-801 (an NMDA open channel blocker), suggesting that NMDA receptor operated channels are involved in TMDT induced spontaneous activity. When considering GABAA receptor activity, diazepam and pregnanolone reversed TMDT activity when applied to cell cultures individually and in combination. MK-801 and ketamine show more antagonistic effects on TMDT than diazepam within cerebral cortical cell cultures of embryonic rats. In vivo mouse models Low dosages of ketamine and MK-801, administered separately, were associated with increased clonic seizures with no effect on tonic clonic seizures on mice exposed to TETS. Further analysis on the same sample of mice, found that dual administration of diazepine and MK-801 had a synergistic protective effect against tonic-clonic seizures and 24-hour lethality, as opposed to clonic seizures that were poorly controlled. Sequential administration diazepine and MK-801 for clonic control of seizures in TETS exposed mice, may indicate the benefits of benzodiazepine-NMDA receptor antagonist regimens used to treat TETS exposed patients. Continued use in China Its use worldwide has been banned since 1984, but due to continuing demand and its ease of production, it is still readily, although illegally, available in China and can be found in some illegally imported rat poisons. The best known Chinese rodenticide, containing about 6–20% TETS, is Dushuqiang, "very strong rat poison". It has been used for mass poisonings in China: in April 2004, there were 74 casualties after eating scallion-flavored pancakes tainted by their vendor's competitor; and in September 2002, 400 people were poisoned and 38 died from contaminated food. In 2002, there was one documented case of accidental poisoning in the US. See also GABAA receptor negative allosteric modulator GABAA receptor § Ligands Strychnine Picrotoxin References Rodenticides GABAA receptor negative allosteric modulators Nitrogen heterocycles Convulsants Sulfur heterocycles Mass poisoning Neurotoxins Adamantane-like molecules Sulfamides Chloride channel blockers Sulfur–nitrogen compounds