Functional observation battery (FOB) or Modified Irwin test

 

The Functional Observational Battery (FOB) is a neurobehavioral valuation tool relating numerous behaviour and neurological activity related parameters of a rat strain. This is a non-invasive process intended to identify gross functional deficits in young adult rats resulting from contact with chemicals and to better enumerate neurotoxic effects sensed in other studies. This battery of tests is not intended to deliver a comprehensive assessment of neurotoxicity. It is planned to be used in combination with neuropathological assessment and/or general toxicity testing. Other functional tests may be essential to evaluate entirely the neurotoxic latent of a chemical.

The modified Irwin test or FOB can be used to accomplish numerous objectives. New chemical entities (NCEs) can be behaviourally separated for nervous system efficacy at different dose level to recognize possible therapeutic uses and in the selection of suitable doses for successive analyses. NCEs can also be estimated in the behavioural battery and associated with reference standards to evaluate obligations in a new compound class, with an assessed therapeutic index being recommended by the doses used in evaluation to therapeutic doses. For the valuation of neurotoxicology, the FOB is frequently used. The differences between the two assays are delicate. The processes used are the same, but when because of neurotoxicology, the FOB is often accompanied using GLP guidelines.

Rats or mice of either or both sexes can be used, and diverse strains of each may be working, keeping in mind that diverse strains may have dissimilar baseline activities. The behavioural observations are completed by uninterrupted home handling observations, cage observations, and open field activity. Some autonomic activity valuations are also involved.

FOB Parameters and how recorded

Sr. No.	Parameters	Recorded as
1.	Measurements
	Bodyweight	Grams
	Rectal temperature	°C
	Hind limb grip performance	Grams force
	Forelimb grip performance	Grams force
	Landing foot splay	Distance (cm) between hind feet
2.	Cage-side observations
	Abnormal movements or behaviour	Description
	Ease of removal	Rank
3.	Hand-held observations
	General (thin, fat, red ocular nasal crusts, etc.)	Description
	Palpebral closure	Rank
	Pupil size	Rank
	Abnormalities of skin or hair coat	Description
	Perineal staining	Present or absent
	Muscle tone	Rank
	Extensor-thrust response	Rank
	Abnormal movements (tremors, convulsions)	Description
	Abnormal respiration (e.g., increased, wheezing)	Description
	Reactivity to handling	Rank
4.	Open-field observations
	Responsiveness to a sharp noise	Rank
	Responsiveness to touch	Rank
	Responsiveness to tail pinch	Rank
	Abnormal behaviour (e.g., stereotypies)	Description
	Level of activity (locomotor, grooming, rearing, etc.)	Rank
	Gait evaluation	Rank
	Urine quantity voided during FOB	Rank
	Number of fecal pellets voided during FOB	Rank
5.	Neurologic examination
	Body temperature	°C
	Heart rates	beats/minute
	Respiratory rates	breaths/minute
	Capillary refill time	Seconds
	Lacrimation and salivation	-
	Sensorimotor/reflex	Seconds
	Wheel barrowing	-
	Righting reflex	Seconds
	Menace reflex	Seconds
	Pupillary light reflex	Seconds
	Palpebral reflex	Seconds
	Nystagmus	-
	Auditory response	-
	Pinna sensitivity	-
	Perineal reflex	Seconds
	Withdrawal reflex	Seconds
	Patellar reflex	Seconds

A FOB is suggested as the first-level neurotoxicity screening in the preclinical safety pharmacology testing guidelines and OECD. Functional observational battery (FOB) procedures have been authorized in several species used in nonclinical studies. Functional observational battery (FOB) data were assessed as continuous, expressive, count, and two variables.