Zinc-enriched (ZEN) terminals in mouse spinal cord: immunohistochemistry and autometallography

The general distribution of zinc-enriched (ZEN) terminals in mouse spinal c ord was investigated at light microscopic level by means of zinc transporte r-3 immunohistochemistry (ZnT3(IHC)) and zinc selenium autometallography (Z nSeAMG). Staining for ZnT3(IHC) corresponded closely to the ZnSeAMG stainin g. Both appeared as dense grains of variable sizes and densities in the gra y matter with a characteristic segmental laminar pattern. The white matter was unstained but contained rows of stained terminals radiating from the gr ay matter. In the dorsal horn, laminae I, III and IV were heavily stained, whereas lamina II appeared as the least stained area in the gray matter. Mo derate staining was seen in laminae V and VI. In the ventral horn, large Zn T3(IHC) and ZnSeAMG grains, known from previous papers to represent ZEN ter minals, were observed related in particular to motor neuronal somata and bi g dendrites. These ZEN terminals in the ventral horn were in general larger than those in the dorsal hem. This is the first description of the pattern of ZEN terminals in mouse spinal cord. (C) 2000 Elsevier Science B.V. All rights reserved.