An intermittent somatostatin-immunoreactivity in the cortex and basal ganglia of the rat

Using light microscopic immunohistochemistry, somatostatin-positive structures were observed in the cortex of the rat. These structures, including cells and fibers, are widely distributed in all cortical laminae and are also found in the basal ganglia. The positive results were obtained exclusively in two groups of animals sacrificed during two different months of two subsequent years. The reason for this variability in the immunocytochemical stainability of cortical structures remains enigmatic.