CRUSTACEAN CARDIOACTIVE PEPTIDE (CCAP) AND CORAZONIN (CRZ) AS PUTATIVE CIRCADIAN CLOCK OUTPUT SIGNALS IN THE CENTRAL NERVOUS SYSTEM OF THE TERRESTRIAL ISOPOD, ARMADILLIDIUM VULGARE (LATREILLE).

Crustacean cardioactive peptide (CCAP)- and corazonin (Crz)-like immunohistochemical reactivity (CCAP-ir and Crz-ir) occurred in small sets of neurons in the cephalic ganglia of the isopod, Armadillidium vulgare. The distribution patterns of both reacitivities were similar in the optic lobe (OL), protocerebrum (PC), tritocerebrum (TC) and suboesophageal mass (SM). Also, these reactivates were co-localized with circadian clock related gene products (CYC and CLK) in the OL and SM; 5 CCAP-ir cells occurred in each OL, weak signals in the pseudofrontal organ (PFO), 2 cells in the PC, one cell in the accessory lobe (AL), a pair of cells in the TC and 10 cells in the SM, while Crz-ir occurred in OL, 12 cells in each lobe. PFO was strongly stained, one cell in PC, pair of cells in TC and 2 pairs of cells in SM one on each side. Double-labeling experiments also showed that some of the detected cells reacted with clock proteins, cycle (CYC) and clock (CLK). They were colocalized with both CCAP-ir and Crz-ir in OL, PFO and the cells of mandibular ganglion (CMD). No difference was found in number or distribution of CCAP-ir or Crz-ir between males and females. The distribution of cells, the projection of immunoreactive fibers to several brain regions, the stomatogastric nervous system and the neurohaemal organs indicated multiple functions of these neuropeptides.