SOME ASPECTS OF INTERNEURONAL CONNECTIONS IN CATS SPINAL GRAY MATTER

The pathways of the neurites of various neurons and their interrelations through axon‐collaterals were investigated in the spinal cord of young kittens using silver impregation techniques. The cells of lamina II connect with other cells of laminae II and III through collaterals. The axons of lamina III cells enter the lateral cord and their collaterals connect with cells of laminae III–IV. The axons of lamina V cells enter the lateral cord and some of their collaterals terminate in the neighborhood and in lamina IX. The cells of lamina VI connect with cells of laminae II–VI. The posterior commissural cells give their collaterals to cells of the intermediate nucleus and of the posterior horn of the both sides. Intermediate‐axoned cells (Valverde, '61) were found in the intermediomedial nucleus and lamina VII. Interconnections of small neurons of each lamina (Rexed, '52, '54) and their physiological significance were discussed. Copyright © 1969 The Wistar Institute of Anatomy and Biology