Aromatic L-amino acid decarboxylase-immunoreactive neurons in and around the cerebrospinal fluid-contacting neurons of the central canal do not contain dopamine or serotonin in the mouse and rat spinal cord.

Using a specific antibody against each of the 4 catecholamine-synthesizing enzymes, dopamine or serotonin, we compared the localization of these substances in rat and mouse spinal cord with two kinds of fixative, such as paraformaldehyde and glutaraldehyde, and two types of sectioning technique, i.e. cryostat and microslicer. In this study, we demonstrated aromatic L-amino acid decarboxylase (AADC)-like immunoreactivity (LI) in cerebrospinal fluid (CSF)-contacting neurons for the first time in the mouse. These cells and some AADC-immunoreactive cells localized outside the subependymal layer of mouse and rat spinal cord did not show tyrosine hydroxylase-, serotonin- and dopamine-LI with and without colchicine treatment.