The African giant rat (Cricetomys gambianus) variously known as the African giant pouched rat or Gambian pouched rat belongs to the genus Cricetomys and order, Rodentia. The rat has large hamster - like pouches on its cheeks from which it derives its name and with which it stores food. The average weight and length of the body of the rat in adult life is 1200g and 38cm respectively. The rat is found in grassland and rain forest zones of Central and West Africa around human habitations and farmlands. The rodent is nocturnal and often seen crossing roads, around drains and in compounds of houses at night. The rat is a social animal with several individuals living together in burrows. It walks and runs on all four legs and is a good jumper and climber. There have been attempts to breed and domesticate the rodent which has show potential for use as a laboratory animal. This book provides detailed description of the gross and histomorphology, morphometry of the spinal cord, cytoarchitectonic organization and laminar distribution of α1 - GABAA neurons in the spinal gray matter and the structure of the spinal nerves and their distribution to the muscles of the African giant rat (AGR).