DISTRIBUTION OF GLYCINE A NEUROTRANSMITTER SUSPECT IN CENTRAL NERVOUS SYSTEM OF SEVERAL VERTEBRATE SPECIES

The glycine concentration in the cerebral hemisphere, diencephalon, midbrain, cerebellum, medulla oblongata, certival enlargement, midthoracic cord, and lumbar enlargement in cat, rat, pigeon, caiman and bullfrog was measured by a specific microchemical assay. The glycine concentration was 3-5 times higher in the medulla oblongata, cervical and lumbar enlargements than in the four brain areas rostral to the medulla. It was low in the mid-thoracic spinal cord and in the cerebellum. An increasing rostrocaudal gradient in glycine concentration was generally noted and was most evident in the cat and rat. The high glycine concentration in the cervical and lumbar spinal cord and the medulla is compatible with a possible transmitter function for glycine in these areas. © 1968.