Observation Irwin test

The Irwin Test (Irwin, S.  Psychopharmacologia, 1968,13, 22-257) is a systematic observational method,
developed to comprehensively assess the state of the mouse (behaviourally, neurologically and autonomically)
to the extent possible through direct observation only. The Irwin Test also permits a reasonable estimate of the
test item duration of action 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.
Below We present you the behaviors and clinical signals observed in Irwin test after Morphine and diazepam administration


Validation Data (observations Irwin test)

observations irwin test

Observation Irwin test

observation irwin test

Motor observation: Catalepsy

Myosis/Mydriasis evaluation

Analgesia observation

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

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Article writes by Veronica Maillo

References: Primary Observation (Irwin) Test in Rodents for Assessing Acute Toxicity of a Test Agent and its Effects on Behavior and Physiological Function. S. Roux, E. Sablé, and R.D. Porsolt. Current Protocols in Pharmacology (2004) 10.10.1-10.10.23