STEREOTROPISM IN RATS AND MICE

Area of Science:

• Behavioral biology
• Neuroscience
• Comparative physiology

Background:

• Stereotropic orientation is a common behavior in invertebrates.
• The presence of similar tropisms in mammals has been debated.
• Understanding mammalian orientation provides insights into fundamental biological responses.

Purpose of the Study:

• To investigate stereotropic orientation in young and congenitally blind adult rodents.
• To determine the sensory modalities involved in this orientation response.
• To compare mammalian stereotropism with that observed in arthropods.

Main Methods:

• Experiments were conducted on young rats and mice, as well as adult congenitally blind mice.
• Sensory deprivation techniques involved the removal of vibrissae, tail, or both.
• Orientation responses were assessed based on the extent of lateral body surface contact.

Main Results:

• Rodents consistently oriented towards lateral surfaces of contact.
• Removal of vibrissae or tail did not significantly alter the stereotropic response.
• Orientation was directed towards the side with more extensive contact when areas were unequal.
• Equal contact on both sides inhibited orientation.

Conclusions:

• Mammalian stereotropic orientation is a robust behavior, independent of specific appendages like vibrissae or tail.
• The response is primarily governed by the extent of body surface contact.
• This behavior in mammals provides a clear example of a tropism, analogous to that seen in arthropods.