Table 2. Behaviour above viewing jar.

Behaviour/Physical Trait	Criteria	Nfix +/+	Nfix +/−
Positional passivity	Struggled when held by tail	100%	100%
Trunk curl	Present	100%	100%
Visual placing	Present	100%	100%
Righting reflex	Present	100%	100%
Pinnal reflex	Present	85%	96%
Vocalisation	Present	50%	60%
Morphology	Normal	100%	100%
Tail pinch	Response	100%	100%
Biting	Present	5%	4%
Limb grasping	Present	65%	54%

Wild-type and Nfix ^+/− mice were held above the viewing jar by the base of the tail whilst a number of physical, behavioural and reflexes were scored. No large differences were apparent between genotypes (Nfix ^+/+, n = 20; Nfix ^+/−, n = 26).