Distribution of calretinin-like immunoreactivity in the brain of Rana esculenta

The distribution of calretinin-like immunoreactivity has been analyzed in t he brain of Rana esculenta. Several neurons of nuclei belonging to sensory pathways, subhabenular area and left habenula were immunopositive. Immunore activity was present in fibers of motor and sensory pathways, thalamus, teg mentum and isthmus. The immunolabeling pattern partially overlapped that pr eviously described in the rat. However, in comparison with the rat, fewer c ells and fibers were immunoreactive and there were less positive brain nucl ei, especially in the pallium, septum and striatum, that were totally negat ive. Taking into consideration that these regions are rather simple in the frog, the presence of calretinin seems to be consistent with the degree of complexity of brain areas and segregation of different nuclei. (C) 1999 Els evier Science B.V. All rights reserved.