Neurotoxin. In vivo, intracranial injection into mice of 10 pmol/g of the peptide induces running in circles and hyperactivity. At higher doses (50 pmol/g), the mice exhibit running and climbing symptoms for close to one hour. Between 130 and 150 pmol/g, characteristic 'spasmodic' symptomatology is elicited. A hand clap would make mice jump high and start running rapidly. When exposed to a loud hand clap, or if the cage cover were dropped, the mice lose motor control and exhibit seizure-like symptoms from which they eventually recover. At the highest doses tested (over 250 pmol/g), after the characteristic spasmodic symptomatology, lethality occurs. Injection of a similar dose range intramuscularly into Siamese fighting fish elicited no unusual symptomatology. Expressed by the venom duct. All different gamma-carboxyalted forms are mostly present in part 2, part 3 and part 4 of the venom duct. They are also found in part 1 (proximal part near the venom bulb) and part 5, but in lower quantity. The cysteine framework is IX (C-C-C-C-C-C). Exists in 4 different forms, depending on gamma-carboxyglutamations. Tx9a-EE does not contain gamma-carboxyglutamate, tx9a-E/gamma has one gamma-carboxyglutamate at position 73, tx9a-gamma/E has one gamma-carboxyglutamate at position 68, and tx9a-agmma/gamma has two gamma-carboxyglutamates at positions 68 and 73. Belongs to the conotoxin P superfamily.