The neuropeptide SIFamide in the brain of three cockroach species

Abstract

The sequence as well as the distribution pattern of SIFamide in the brain of different insects is highly conserved. As a general rule, at least four prominent SIFamide-immunoreactive somata occur in the pars intercerebralis. They arborize throughout the brain and the ventral nerve cord. Whereas SIFamide is implicated in mating and sleep regulation in Drosophila, other functions of this peptide remain largely unknown. To determine whether SIFamide plays a role in the circadian system of cockroaches, we studied SIFamide in Rhyparobia (= Leucophaea) maderae (Blaberidae), Periplaneta americana (Blattidae), and Therea petiveriana (Polyphagidae). Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry revealed identical SIFamide sequences (TYRKPPFNGSIFamide) in the three species. In addition to four large immunoreactive cells in the pars intercerebralis (group 1), smaller SIFamide-immunoreactive somata were detected in the pars intercerebralis (group 2), in the superior median protocerebrum (group 3), and in the lateral protocerebrum (group 4). Additional cells in the optic lobe (group 5) and posterior protocerebrum (group 6) were stained only in P. americana. Almost the entire protocerebrum was filled with a beaded network of SIFamide-immunoreactive processes that especially strongly invaded the upper unit of the central body. Double-label experiments did not confirm colocalizations with γ-aminobutyric acid (GABA) or the circadian coupling peptide pigment-dispersing factor (PDF). In contrast to locusts, colocalization of SIFamide and histamine immunoreactivity occurred not in group 1, but in group 4 cells. Because the accessory medulla displayed SIFamide immunoreactivity and injections of SIFamide delayed locomotor activity rhythms circadian time-dependently, SIFamide plays a role in the circadian system of cockroaches. J. Comp. Neurol. 524:1337-1360, 2016. © 2015 Wiley Periodicals, Inc.

PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana

“…Because of its generous size and simple animal maintenance, P. americana is well suited for studying the morphology, physiology, and pharmacology of the insect nervous system. Such research has led to a better understanding of the neural basis of escape behavior [ 4 , 5 ], circadian rhythmicity [ 6 , 7 ], and neuropeptide distribution and action [ 8 , 9 , 10 ]. In addition, various learning paradigms have been established for P. americana during the last few years [ 11 , 12 , 13 , 14 , 15 ].…”

SIFamide Influences Feeding in the Chagas Disease Vector, Rhodnius prolixus

“…In P. americana, in addition to the conserved cells in the pars interecerebralis, SIFamidergic cells were also seen in the OLs and posterior protocerebrum (Arendt et al, 2016). Neuronal circuits for SIFamide seemed to be colocalized with pigment-dispersing factor, histamine, and gamma amino butyric acid, suggesting that SIFamide may be involved in regulating rhythmic behavior associated with the circadian system (Arendt et al, 2016). Similarly, immunohistochemical data from D. melanogaster also reveals synapses between the four SIFamidergic neurons and DN1 dorsal clock circadian pacemaker neurons (Cavanaugh et al, 2014), suggesting SIFamide may constitute an element in modulating behaviors governed by the circadian clock.…”

“…The presence of extensive SLI in the OLs of R. prolixus may suggest a potential function in mediating rhythmic behavior guided by environmental cues such as locomotion, feeding, and ecdysis (Davey, 2007). In P. americana, in addition to the conserved cells in the pars interecerebralis, SIFamidergic cells were also seen in the OLs and posterior protocerebrum (Arendt et al, 2016). Neuronal circuits for SIFamide seemed to be colocalized with pigment-dispersing factor, histamine, and gamma amino butyric acid, suggesting that SIFamide may be involved in regulating rhythmic behavior associated with the circadian system (Arendt et al, 2016).…”

Functions of corazonin and histamine in light entrainment of the circadian pacemaker in the Madeira cockroach,Rhyparobia maderae

“…The antiserum has been used in several studies (Sullivan et al, ; van Meer et al, ; Greferath et al, ), one of which demonstrated its reliability in insects (Hamanaka et al, ). Also in R. maderae , liquid‐phase preadsorption of the antiserum with 100 µM of a histamine–BSA conjugate was sufficient to abolish the staining completely (Arendt et al, ). Preadsorption with Rhm ‐corazonin in double‐label experiments had no effect on the histamine staining.…”

“…The monoclonal PDF antibody (RRID:AB_760350; Table ) was obtained from cell cultures of hybridoma cells (Cyran et al, ) purchased from the Developmental Studies Hybridoma Bank (Department of Biology, University of Iowa, Iowa City, IA) and has been used in a variety of studies analyzing the circadian system of R. maderae (Soehler et al, ; Wei and Stengl, ; Schulze et al, ; Arendt et al, ). The specificity of this antibody has also been demonstrated with liquid‐phase preadsorption, given that 10 µM of Rhm ‐PDF was sufficient to abolish the staining completely (Schulze et al, 2012).…”