Comparative anatomy of pigment-dispersing hormone-immunoreactive neurons in the brain of orthopteroid insects

Homberg, Uwe; Würden, Stefan; Dircksen, Heinrich; Rao, K. Ranga

doi:10.1007/bf00318190

Cited by 161 publications

(199 citation statements)

References 36 publications

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“…2A). This small neuropil was first found in holometabolous insects as a remnant of the larval optic neuropil (Pflugfelder, 1936), but also exist in hemimetabolous insects (Homberg et al, 1991). The most convincing evidence for its importance is that transplantation of the tissue into optic lobeless cockroaches restored locomotor rhythms in L. maderae .…”

Section: Locus Of the Clockmentioning

confidence: 92%

Circadian Organization in Hemimetabolous Insects

Tomioka

Abdelsalam

2004

Zoological Science

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ABSTRACT-The circadian system of hemimetabolous insects is reviewed in respect to the locus of the circadian clock and multioscillatory organization. Because of relatively easy access to the nervous system, the neuronal organization of the clock system in hemimetabolous insects has been studied, yielding identification of the compound eye as the major photoreceptor for entrainment and the optic lobe for the circadian clock locus. The clock site within the optic lobe is inconsistent among reported species; in cockroaches the lobula was previously thought to be a most likely clock locus but accessory medulla is recently stressed to be a clock center, while more distal part of the optic lobe including the lamina and the outer medulla area for the cricket. Identification of the clock cells needs further critical studies. Although each optic lobe clock seems functionally identical, in respect to photic entrainment and generation of the rhythm, the bilaterally paired clocks form a functional unit. They interact to produce a stable time structure within individual insects by exchanging photic and temporal information through neural pathways, in which serotonin and pigment-dispersing factor (PDF) are involved as chemical messengers. The mutual interaction also plays an important role in seasonal adaptation of the rhythm.

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Section: Locus Of the Clockmentioning

confidence: 92%

Circadian Organization in Hemimetabolous Insects

Tomioka

Abdelsalam

2004

Zoological Science

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“…The anti-pigment-dispersing hormone (PDH) serum (#3B3, used at dilutions of 1:20,000) was raised in rabbit against conjugates of synthetic Uca pugilator/Cancer magister ␤-PDH and bovine thyroglobulin. Its specificity was demonstrated by Dircksen et al (1987) and Homberg et al (1991).…”

Section: Methodsmentioning

confidence: 97%

Polarization-Sensitive Descending Neurons in the Locust: Connecting the Brain to Thoracic Ganglia

Träger¹,

Homberg²

2011

J. Neurosci.

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Many animal species, in particular insects, exploit the E-vector pattern of the blue sky for sun compass navigation. Like other insects, locusts detect dorsal polarized light via photoreceptors in a specialized dorsal rim area of the compound eye. Polarized light information is transmitted through several processing stages to the central complex, a brain area involved in the control of goal-directed orientation behavior. To investigate how polarized light information is transmitted to thoracic motor circuits, we studied the responses of locust descending neurons to polarized light. Three sets of polarization-sensitive descending neurons were characterized through intracellular recordings from axonal fibers in the neck connectives combined with single-cell dye injections. Two descending neurons from the brain, one with ipsilaterally and the second with contralaterally descending axon, are likely to bridge the gap between polarization-sensitive neurons in the brain and thoracic motor centers. In both neurons, E-vector tuning changed linearly with daytime, suggesting that they signal time-compensated spatial directions, an important prerequisite for navigation using celestial signals. The third type connects the suboesophageal ganglion with the prothoracic ganglion. It showed no evidence for time compensation in E-vector tuning and might play a role in flight stabilization and control of head movements.

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“…Even though the distributed location of circadian functions and the supposed lack of a conspicuous pacemaker in the brain may indicate that crustacean clock structures are significantly different from those in insects, the recent identification of some neurons in lobsters (H. americanus) that are homologous to clock neurons in Drosophila and other insects rather gives hints to expect strikingly similar organisations in insect and crustacean clocks. These PDH-ir neurons of the lobster are very similar to the s-LN v s that express the homologous neuropeptide PDF, a clock output of a group of Drosophila pacemakers, which controls the morning bout of locomotory activity (60,213,214), the coordinative l-LN v s of Drosophila (or optic lobe 2-neurons in Phormia terraenovae flies; 325) and the large PDFMe clock neurons of other insects innervating the accessory medulla and the contralateral optic lobes (213,215,216,318).…”

Section: Putative Clock Neurons Conserved In Crustaceans and Insectsmentioning

confidence: 98%

“…The crustacean PDH-neuron systems are, thus, much more complex than similar neurons in insects that likely express only one single isoform of the orthologous insect pigment dispersing factor PDF (95). For instance, in Drosophila, PDF is a known clock output factor that is expressed in the well-established socalled large and small ventral lateral neurons (4 l-LN v s and 4 s-LN v s) next to the medullae (212)(213)(214), which are homologues of the so-called PDFMe neurons of several orthopteroid insects (215,216). Putative homologies of the insect PDFMe/LN v -type and crustacean lateral medulla-associated (crab C-type) neurons make PDFs and PDHs potential key circadian molecules and PDH likely a suitable marker for clock neurons in crustaceans (see 4.2., cp.…”

Section: Crustacean Hyperglycaemic Hormone (Chh)mentioning

confidence: 99%

Circadian clocks in crustaceans: identified neuronal and cellular systems

Strauß

Dircksen²

2010

Front Biosci

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Circadian rhythms are known for locomotory and reproductive behaviours, and the functioning of sensory organs, nervous structures, metabolism and developmental processes. The mechanisms and cellular bases of control are mainly inferred from circadian phenomenologies, ablation experiments and pharmacological approaches. Cellular systems for regulation summarised here comprise the retina, the eyestalk neuroendocrine X-organ-sinus gland system, several neuropeptides such as red pigment concentrating, hyperglycaemic and pigment-dispersing hormones, and factors such as serotonin and melatonin. No master clock has been identified, but a model of distributed clockwork involves oscillators such as the retinular cells, neurosecretory systems in the optic lobes, putative brain pacemakers, and the caudal photoreceptor. Extraretinal brain photoreceptors mediate entrainment. Comparative analyses of clock neurons and proteins known from insects may allow the identification of candidate clock neurons in crustaceans as putative homologues in the two taxa. Evidence for the existence of "insect-like" intracellular clock proteins and (light sensitive) transcription factors is scarce, but clock-, period-, and cryptochrome-gene products have been localised in the CNS and other organs rendering further investigations into crustacean clockwork very promising.

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Comparative anatomy of pigment-dispersing hormone-immunoreactive neurons in the brain of orthopteroid insects

Cited by 161 publications

References 36 publications

Circadian Organization in Hemimetabolous Insects

Circadian Organization in Hemimetabolous Insects

Polarization-Sensitive Descending Neurons in the Locust: Connecting the Brain to Thoracic Ganglia

Circadian clocks in crustaceans: identified neuronal and cellular systems

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