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Naked mole-rats (Heterocephalus glaber) are remarkabe rodents that live underground in Africa. They are “eusocial” – living in colonies with a single breeding female, a few male drones, and non-reproductive workers. They have small eyes and ears but a keen sense of touch. Their bodies are covered with small sensory hairs used for orienting in dark tunnels. |
| Naked mole-rat neocortex is dominated by the somatosensory area (S1). This large map of the contralateral body surface takes up a much greater proportion of the neocortex in mole-rats than is the case for other rodents. The area typically devoted to vision in mammals is occupied by part of the somatosensory map (PDF of Paper). |  |
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The “moleratunculus” illustrated to the left shows the proportions of body parts as represented in the mole-rat brain. A surprisingly large area of the somatosensory map is devoted to the front teeth. Mole-rats use their teeth to dig extensive tunnels and for manipulating objects, making the incisors an important sensory structure (drawing by Lana Finch). |
| When a new queen takes over the colony and begins to reproduce, her spinal column lengthens to accommodate an expanded reproductive tract and large litters of young (sometimes 20 or more embryos). X-rays of transitioning queens (right) show that most of this bone growth occurs during pregancies (PDF of Paper). |  |