Observation Irwin test

The Irwin test (Irwin, S. Psychopharmacologia (1968) 13:222-57) is a systematic observational method, developed to comprehensively assess the behavioral, neurological and autonomic state of the mouse insofar as possible only through direct observation. The Irwin test also permits a reasonable estimate of the duration of action of the test item on the different parameters observed.

Since most measures involve subjective assessment of different aspects of the animal´s behavior, the test must be performed in a highly standardized manner. Therefore, behavioral modifications, physiological and neurotoxicity symptoms, rectal temperature and pupil diameter are recorded according to a standardized observation grid derived from that of Irwin.

The behaviors and clinical signs observed in the Irwin test after diazepam and morphine administration are shown below:


Validation Data (observations Irwin test)

observations irwin test

Table: Behaviors and clinical signs observed in the Irwin test after diazepam and morphine administration. The values are expressed as the number of mice showing the parameter per total mice evaluated. Diazepam and morphine (CSN depressants) were used as references compounds and saline as control.

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Article written by Veronica Maillo


Primary Observation (Irwin) Test in Rodents for Assessing Acute Toxicity of a Test Agent and its Effects on Behavior and Physiological Function. Roux S, Sablé E, and Porsolt RD. Current Protocols in Pharmacology (2005) Jan 1;Chapter10:Unit 10.