VASOACTIVE INTESTINAL POLYPEPTIDE IMMUNOREACTIVE STRUCTURES IN THE MOUSE BARREL FIELD

Immunohistochemistry for vasoactive intestinal polypeptide was carried out in tangentially cut vibratome sections of the barrel cortex in ad ult mice. Sections through layer IV have revealed an association betwe en the cytoarchitectonically visible modular organization of barrels a nd the distribution of immunoreactive axon terminals. These terminals are preferentially localized in the side region of a barrel, whereas t he hollow shows a relative scarcity of these structures as shown with image analysis. This finding is the first direct demonstration of a mo dular distribution of vasoactive intestinal polypeptide-containing axo n terminals in the neocortex.