Tetramethylenedisulfotetramine (TETS) is an organic compound used as a rodenticide (rat poison). It is an odorless, tasteless white powder that is slightly soluble in water, DMSO and acetone, and insoluble in methanol and ethanol. It is a sulfamide derivative. It can be synthesized by reacting sulfamide with formaldehyde under acidic condition. When crystallized from acetone, it forms cubic crystals with a melting point of 255–260 °C. Toxicity and mechanism TETS is a neurotoxin and convulsant, causing lethal convulsions. Its effect is similar to but stronger than picrotoxin, a GABA-A receptor antagonist widely used in research. As one of the most hazardous pesticides, it is 100 times more toxic than potassium cyanide. TETS binds to neuronal GABA gated chloride channels, often causing status epilepticus. No antidote is known. The lethal dose for humans is 7–10 mg. Poisoning is diagnosed by GC-MS and the treatment is mainly supportive, with large IV doses of a benzodiazepine (e.g clonazepam) and pyridoxine to control symptoms. TETS is sequestered in tissues of poisoned birds and can thus pose severe risk of secondary poisoning. History Previous research has documented the effectiveness of Tetramethylenedisulfotetramine against mice. The dangers of this chemical were first suspected in 1949. The U.S. Forest Service, looking to protect tree seeds for reforestation, noted its lethal effect against the rodent populations. Rather than repel wandering scavengers, the chemical was proved to be toxic to the local rodent population for up to 4 years. Continued experiments conducted by the U.S. Forest Service found no direct effect between TETS and the gastro-intestinal or renal systems of spinal dogs. In this same study, no effects were seen within the peripheral or skeletal nerve system, limiting symptoms of toxicity to the brain stem. Curtis and Johnson were the first to hypothesize TETS antagonistic behavior on GABA. An in-vitro study using superior cervical ganglion neurons of rats found TETS to antagonize the depolarization actions of GABA, while having no influence on the cholinomimetic agent carbachol. This evidence suggests that TETS may act as a non-competitive inhibitor for GABA. Further research findings using crustacean models, indicated a dose-dependent, non-competitive response to TETS that is reversible. Research In vitro and rapid screening tools Recent studies have indicated the usefulness of pH sensitivity in identifying Chloride ion influx, resulting from GABAA receptor excitation. Other potential screening tools include spontaneous Calcium ion oscillations seen in hippocampal cell cultures from new born mice. This