CALCITONIN-GENE-RELATED PEPTIDE-LIKE IMMUNOREACTIVE (CGRPI) ELEMENTS IN THE CIRCADIAN SYSTEM OF THE MOUSE - AN IMMUNOHISTOCHEMISTRY COMBINED WITH RETROGRADE TRANSPORT STUDY

This study was based on immunohistochemical detection of calcitonin ge ne-related peptide-like immunoreactive (CGRPI) neurons and fibers in t he suprachiasmatic nucleus (SCN) and intergeniculate leaflet (IGL) of the mouse. CGRPI neurons and fibers were found within the ventrolatera l part of the SCN, in the whole extent of IGL and sparsely distributed in ventral lateral geniculate body. The presence of CGRPI structures in the SCN and IGL of the mouse further supports the hypothesis of dif ferences in the content of neuroactive substances in the circadian clo ck between mammalian species. Fluorogold retrograde transport combined with CGRP immunofluorescence demonstrates that CGRPI neurons in the I GL constitute a part of IGL reciprocal connections.