Behavioural ontogeny of looptail mice

• 1.1. For the purpose of comparing the behavioural development of looptail (Lp/+) mice and normal (+/+) mice, twenty-eight components performed by single males were screened by direct observation on days 3, 8, 10, 14, 17, and approximately 31 after birth.
• 2.2. The data on the behaviour of normal mice confirmed earlier findings. Apart from wobbly head movements, mutants showed at specific ages decreased frequencies of twitching, pivoting, three grooming activities, leaning postures, rearing, climbing, and vibrating with the forelegs.
• 3.3. These results are related to previous findings in older looptails and discussed in terms of the abnormal development of certain brain structures.