Diazinon: A cholinesterase inhibitor that is used as an organothiophosphorus insecticide.Chlorpyrifos: An organothiophosphate cholinesterase inhibitor that is used as an insecticide and as an acaricide.Dieldrin: An organochlorine insecticide whose use has been cancelled or suspended in the United States. It has been used to control locusts, tropical disease vectors, in termite control by direct soil injection, and non-food seed and plant treatment. (From HSDB)Insecticides: Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.Parathion: A highly toxic cholinesterase inhibitor that is used as an acaricide and as an insecticide.Dichlorvos: An organophosphorus insecticide that inhibits ACETYLCHOLINESTERASE.Pesticides: Chemicals used to destroy pests of any sort. The concept includes fungicides (FUNGICIDES, INDUSTRIAL); INSECTICIDES; RODENTICIDES; etc.Dimethoate: An organothiophosphorus cholinesterase inhibitor that is used as a systemic and contact insecticide.Cholinesterase Inhibitors: Drugs that inhibit cholinesterases. The neurotransmitter ACETYLCHOLINE is rapidly hydrolyzed, and thereby inactivated, by cholinesterases. When cholinesterases are inhibited, the action of endogenously released acetylcholine at cholinergic synapses is potentiated. Cholinesterase inhibitors are widely used clinically for their potentiation of cholinergic inputs to the gastrointestinal tract and urinary bladder, the eye, and skeletal muscles; they are also used for their effects on the heart and the central nervous system.Organothiophosphorus Compounds: Compounds containing carbon-phosphorus bonds in which the phosphorus component is also bonded to one or more sulfur atoms. Many of these compounds function as CHOLINERGIC AGENTS and as INSECTICIDES.Organophosphorus Compounds: Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.Receptors, Serotonin, 5-HT2: A subclass of G-protein coupled SEROTONIN receptors that couple preferentially to the GQ-G11 G-PROTEINS resulting in increased intracellular levels of INOSITOL PHOSPHATES and free CALCIUM.Piperonyl Butoxide: An insecticide synergist, especially for pyrethroids and ROTENONE.Organophosphates: Carbon-containing phosphoric acid derivatives. Included under this heading are compounds that have CARBON atoms bound to one or more OXYGEN atoms of the P(=O)(O)3 structure. Note that several specific classes of endogenous phosphorus-containing compounds such as NUCLEOTIDES; PHOSPHOLIPIDS; and PHOSPHOPROTEINS are listed elsewhere.Pesticide Residues: Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.Malathion: A wide spectrum aliphatic organophosphate insecticide widely used for both domestic and commercial agricultural purposes.Neurotoxicity Syndromes: Neurologic disorders caused by exposure to toxic substances through ingestion, injection, cutaneous application, or other method. This includes conditions caused by biologic, chemical, and pharmaceutical agents.