Successful intracerebroventricular cannulation of a eusocial mammal

Manipulating neural activity in live animals within a colony would allow researchers to more fully explore the neurobiology of complex social behaviors. However, some colony-living animals like the naked mole-rat (Heterocephalus glaber) cannot be reintroduced to a colony after the extended recovery time required following cranial surgery. Furthermore, the colony setting creates increased risk of infection and interruption of cranial surgical sites.

A protocol for intracerebroventricular cannulations was developed for securing and minimizing exposure of the intracranial apparatus. We tested whether animals could be reintroduced to the colony immediately following surgery and whether they showed full recovery and expression of normal behavior a week later, after intracerebroventricular infusion of saline.

Animals were successfully reincorporated into their home colony and showed normal behavior. No animals lost guide cannulae within their colony and loss of dummy cannulae was minimized. Any loss of animals was due to surgical complications or multiple intracerebroventricular infusions of saline rather than recovery in the colony, per se.

Standard cranial cannulation methods for small rodents were used with the addition of implanting a shortened guide cannula under the skin for limited exposure of cannulae to the external environment. Furthermore, dummy cannulae were sealed to guides to avoid loss in-colony.

The use of intracranial cannulations is a viable option for colony-living rodents when the proper care is taken to minimize cannula exposure and when animals are carefully and promptly reintroduced to the colony setting after surgery.