An analysis of feeding and sensorimotor abilities of rats after decortication.

Feeding and sensorimotor abilities of decorticate rats are described. Within 24 hr after surgery, the rats ate mash, unfamiliar foods, dry chow, and tap and sugar water from a spatula. They sampled nonnutritive substances but rejected noxious substances. Although initially anorectic, given mash, they arrested weight loss as early as 2 to 4 days. With training, they drank water from a spout by Day 10 and gained weight on dry food and water. Throughout survival they had difficulties with chewing food, lapping water, and trimming toenails. They showed sensorimotor neglect to objects touched to the body; they did not orient to the place in space where touched, they did not orient when touched on the head. There may be different types of orienting, one which is lost and one spared following decortication. When lifted from a surface, they showed limb and postural abnormalities; when dropped, righting responses were impaired. They showed stereotyped reflexive responses to surface and became trapped on platforms and in alleys. The range of abnormalities, from simple acts to more complex behaviors, considered within the context of feeding behavior in its broadest sense, shows the rats simplest environment. Furthermore, cortically controlled feeding seems partly independent from hypothalamically controlled feeding.