Regeneration of tactile lamellar corpuscles of the rat after postnatal freeze injury

Abstract

 Tactile lamellar corpuscles were studied after freeze injury of rat toe pads under normal conditions and following permanent denervation in 1- to 65-day-old animals. In the innervated skin, digital corpuscles redifferentiated in all age groups examined during development and maturation. Characteristic of the reinnervated skin was a great diversity in the shape and size of newly formed corpuscles. Small corpuscles with only 1–3 lamellae around their terminals and well-developed corpuscles of about normal size with up to 15 lamellae were sometimes found within the same sample of skin. The regenerated corpuscles were reduced in number; they reappeared in only 50% of dermal papillae in the toe pads after freeze injury in 7-week-old rats, compared with approximately 100% of dermal papillae that contained lamellar corpuscles in normal toe-pad skin. In denervated toes, occasional corpuscular lamellar structures appeared first after freeze injury applied to 34-day-old rats. In the toe pads denervated and injured by freezing in 42- and 49-day-old rats, lamellar structures redifferentiated in about 10% of the papillae, and in 23.5% after freeze injury applied to 2-month-old rats. Unsatisfactory preservation of basal laminae at the former sites of the corpuscles and in the acellular peripheral nerve stumps, and/or insufficient migration of Schwann cells, may be responsible for the absence or abortive regeneration of lamellar structures in denervated skin of food pads after freeze injury in young rats.