The Irwin Test and Functional Observational Battery (FOB) for Assessing the Effects of Compounds on Behavior,...

The modified Irwin procedure or functional observational battery (FOB) can be used to achieve several goals. New chemical entities (NCEs) can be behaviorally screened for nervous system effects at a variety of doses to identify potential therapeutic uses and in the selection of appropriate doses for subsequent assays. NCEs can also be evaluated in the behavioral battery and compared with reference standards to assess liabilities in a new compound class, with an estimated therapeutic index being suggested by the doses used in comparison to therapeutic doses. For the assessment of neurotoxicology, the FOB is often used. The differences between the two assays are subtle. The procedures used are essentially the same, but when considering neurotoxicology, the FOB is often conducted using GLP guidelines, with more animals being used per group, and doses that are low enough to determine a no effect level and high enough to induce marked nervous system behaviors. © 2023 Wiley Periodicals LLC. Basic Protocol: The Irwin test and FOB for assessing the effects of compounds on behavior, physiology, and safety pharmacology in rodents.