Serotonin-immunoreactive neurons in the antennal lobes of the American cockroach Periplaneta americana: light- and electron-microscopic observations

A large deutocerebral serotonin-immunoreactive neuron arborizes profusely in the glomeruli of the antennal lobes, and also sends neurites into the lateral lobe and the calyces of the mushroom bodies in the ipsilateral protocerebrum. Electron micrographs of the glomerular neuropil show that the main synapses of the serotonin-immunoreactive arborizations are output contacts with unidentified neuron profiles. Only a few synaptic input contacts with serotonin-labeled fibers were observed.     

Serotonin-immunoreactive neurons in the antennal lobes and suboesophageal ganglion of the honeybee

Summary We have used immunohistochemical methods to investigate the morphology of identified, presumptive serotonergic neurons in the antennal lobes and suboesophageal ganglion of the worker honeybee. A large interneuron (deutocerebral giant, DCG) is described that interconnects the deutocerebral antennal and dorsal lobes with the suboesophageal ganglion and descends into the ventral nerve chord. This neuron is accompanied by a second serotonin-immunoreactive interneuron with projections into the protocerebrum. Two pairs of bilateral immunoreactive serial homologues were identified in each of the three suboesophageal neuromeres and were also found in the thoracic ganglia. With the exception of the frontal commissure, no immunoreactive processes could be found in the peripheral nerves of the brain and the suboesophageal ganglion. The morphological studies on the serial homologues were extended by intracellular injections of Lucifer Yellow combined with immunofluorescence.     

Postembryonic development of the antennal lobes in Periplaneta americana L.

Summary The postembryonic development of the antennal lobes of Periplaneta americana L. was examined with light- and electron-microscopical methods. There is no difference in the number of glomeruli and neurons in the antennal lobes of larval and adult animals. At hatching, the first larva already possesses the adult number of approximately 125 glomeruli and 500 to 560 deutocerebral neurons in the dorsolateral cell group of each antennal lobe. During postembryonic development the volume of the deutocerebral neurons increases three- to fourfold. The glomeruli of the first larva have about 7 % of the volume of the corresponding adult glomeruli. Since number, pattern, and size ratio of glomeruli (with the exception of the macroglomerulus) are constant in all larval stages and adult animals, it is possible to identify individual glomeruli. During the whole postembryonic development the ordinary glomeruli show a continuous volume increase, which parallels the increase in antennal sensory input. The macroglomerulus develops by way of special growth of two to four neuropil units, but not before the last three to four larval stages and only in males. Its growth precedes the formation of antennal pheromone receptors during the final molt; these receptors are known to project into the macroglomerulus. The development of the macroglomerulus in the last larval stages of the male may be caused by a genetically fixed growth program of specific deutocerebral neurons.Supported by the Deutsche Forschungsgemeinschaft (Scha 291/1)     

Serotonin-immunoreactive visceral nerves and neurohemal system in the cockroach Periplaneta americana (L.)

Summary By use of the indirect immunofluorescent technique applied to whole mounts of tissues and organs of the American cockroach, Periplaneta americana, serotonin-like reactivity has been demonstrated in an extensive meshwork of fibers on the surface of nerves of the subesophageal ganglion and the tritocerebrum. This meshwork appears to serve the neurohemal release of serotonin. In addition, several of these nerves contain two or more centrally located axons that appear to be serotonergic. The corpora cardica show immunoreactivity but do not appear to be a principal release site for serotonin. The nerves and ganglia of the stomadeal nervous system show immunoreactivity for serotonin and provide serotonin-positive innervation to the salivary glands and the visceral muscles of the stomodeum and midgut. The heart, hindgut, Malpighian tubules, fat body, and skeletal muscles all appear to lack serotonin immunoreactivity.     

Synaptic connections of dopamine-immunoreactive neurons in the antennal lobes of Periplaneta americana. Colocalization with GABA-like immunoreactivity

Dopamine-like immunoreactivity was demonstrated histochemically in about ten local interneurons in the antennal lobe of Periplaneta americana. The somata of these neurons are within the ventrolateral group of cell bodies. Additional immunohistochemical tests revealed that the same neurons also have a GABA-like immunoreactivity. Immunohistochemical dopamine staining (preembedding) of preparations in which the antennal receptor fibers had been caused to degenerate showed that in the glomerular neuropil these antennal fibers form output synapses on dopamine-immunoreactive neurons. The latter form output synapses on unstained neuron profiles.     

Synaptic connections of dopamine-immunoreactive neurons in the antennal lobes of Periplaneta americana. Colocalization with GABA-like immunoreactivity

Summary Dopamine-like immunoreactivity was demonstrated histochemically in about ten local interneurons in the antennal lobe of Periplaneta americana. The somata of these neurons are within the ventrolateral group of cell bodies. Additional immunohistochemical tests revealed that the same neurons also have a GABA-like immunoreactivity.Immunohistochemical dopamine staining (preembedding) of preparations in which the antennal receptor fibers had been caused to degenerate showed that in the glomerular neuropil these antennal fibers form output synapses on dopamine-immunoreactive neurons. The latter form output synapses on unstained neuron profiles.     

Wing receptors of the American cockroach Periplaneta americana]

Wing receptors of the cockroach have been studied using staining technique with methylene blue in living animals. Five types of the receptors were found: trychoid hairs, bristles, complaniform sensillae, chordotonal organs and multiterminal neurons. The majority of the receptors is located at the lower surface of the wing, especially along its ribs. Together with primitive features in the structure (polyneuronal origin of hairs and bristles, poor content of chordotonal organs, absence of distinct groups of companiform sensillae), some specialization of wing receptors with respect to flight function is noted (concentration of proprioceptors along the main mechanical axis of the wing and formation of distinct rows by the companiform sensillae).     

Type II neurons in the trunk of the cockroach Periplaneta americana

Staining the nervous system by methylene blue, studies have been made on the topography and structure of type II neurones in the trunk of the cockroach. Small quantity of cells innervating various tissues was found together with 3 varieties of neurones, located near the nervous trunks, as well as 4 pairs of the abdominal stretch receptors (one pair of unicellular and one pair of bicellular receptors in tergites and sternites).     

Distribution of GABA-like immunoreactive neurons in the optic lobes of Periplaneta americana

Summary Specific antisera against protein-conjugated -aminobutyric acid (GABA) were used in immunocytochemical staining procedures to study the distribution of the putative GABA-like immunoreactive neurons in the optic lobes of Periplaneta. GABA-like immunoreactive structures are evident in all three optic neuropil regions. Six different populations of GABAergic neurons, whose perikarya are grouped around the medulla, are found within the optic lobe. The number of these immunoreactive cells varies greatly and corresponds to the number of ommatidia of the eye. In the proximal part of the lamina, a coarse network of GABA-positive fibres is recognizable. These are the processes of large field tangential cells whose fibres pass through the distal surface of the medulla. A second fibre population of the lamina is made up of the processes of the centrifugal columnar neurons whose perikarya lie proximally to the medulla. The medulla contains 9 layers with GABAergic elements of variable immunoreactivity. Layers 1, 3, 5, 7 and 9 exhibit strong labelling, as a result of partial overlapping of the processes of centrifugal and centripetal columnar neurons, tangential fibres and/or lateral processes of perpendicular fibres and (possibly) processes of amacrines. A strong immunoreactivity is found in the proximal and distal layers of the lobula.     

美洲大蠊粪便粗提物的聚集活性

用不同溶剂不同方法提取美洲大蠊Periplaneta americana(L.)粪便,测定美洲大蠊各虫态的诱集活性。结果表明,采用直接浸泡提取方法,丙酮、乙醇、正己烷和二氯甲烷4种粗提物对美洲大蠊各虫态都具有明显的诱集作用,其中乙醇和丙酮粗提物的引诱效果最好,正己烷次之,二氯甲烷最弱。4种溶剂粗提物对美洲大蠊雄成虫和高龄若虫聚集活性最强,对低龄若虫聚集活性最弱。用乙醇溶剂对粪便粗提,3种提取方法均对美洲大蠊有很强的诱集效果,其中索氏抽提诱集效果最弱,直接浸泡和超声波提取效果好,且差异不显著,但直接浸泡提取效果更好。     

Immunofluorescent localization of dopamine-like and leucine-enkephalin-like neurons in the supraoesophageal ganglia of the American cockroach, Periplaneta americana

Leucine-enkephalin- and dopamine-like nerve cells and fibers were localized in the supraoesophageal ganglia (brain) of the American cockroach, Periplaneta americana, using immunofluorescence. The presence of leucine-enkephalin-like material was confirmed using immunoperoxidase staining. Several cells containing leucine-enkephalin-like material were found in the pars lateralis, and nerve fibers belonging to these cells were traced through the brain. Dopamine-like material was detected in deutocerebral neurons as well as the nerve processes arising from these cells which lead into the area of the deutocerebral glomeruli. Specific immunofluorescence was also obtained in the alpha and beta lobes of the corpora pedunculata with both the leucine-enkephalin and dopamine antibodies. However, the fluorescent banding pattern observed in both lobes was distinctly different with the two antibodies. No specific fluorescence was observed in the stalk or peduncle of the corpora pedunculata with either the leucine-enkephalin or the dopamine antibody. The findings suggest a possible interaction of leucine-enkephalinergic and dopaminergic nerve fibers in the alpha and beta lobes of the cockroach corpora pedunculata.     

Purification and characterization of vitellogenin from the American cockroach,Periplaneta americana

• 1.1. Vitellogenin (VG) was isolated and purified from the hemolymph of female American cockroaches.
• 2.2. The purification method used in this study comprises two steps: the first step is based on the method originally developed for purifying lipophorin from hemolymph, and the second step is the separation of VG from lipophorin by a KBr density gradient ultracentrifugation.
• 3.3. The purified VG was characterized according to molecular weight, substructure, shape and size, and lipid composition.
• 4.4. The VG molecule is almost globular in shape with the diameter of about 15.5 nm and is indistinguishable from lipophorin in shape and size.
• 5.5. The native molecular weight determined by light scattering method was 560 kDa.
• 6.6. The VG consists of four subunits with molecular weights of approximately 102, 81, 49 and 40 kDa, respectively.
• 7.7. VG is a lipoprotein and comprises 92% protein and 8% lipid.
• 8.8. Major lipid components were found to be diacylglycerol (25%) and phospholipids (71%).

     

Spectral transmission through the cuticle of the American cockroach,Periplaneta americana

Small pieces of cuticle were removed from the following areas of the cockroach, P. americana, to determine the relative transmittance qualities across the visible and infrared regions of the spectrum: wing tip; abdominal tergite and sternite; light and dark pigmented areas of the pronotum; vertex; two pairs of wing tips plus underlying tergite. The transmittance across the spectral areas investigated showed significant differences in μW/cm² between the cuticular areas assayed. A single wing tip possessed high transmittance qualities whereas the vertex and lesser pigmented cuticle showed considerably lower per cent transmission.     

Alkaline phosphatase activity in the brain of the American cockroach Periplaneta americana L

Summary The supra- and suboesophageal ganglia of the American cockroach contain material which catalyses the alkaline hydrolysis (pH 9.5) of 5-bromo-4-chloro-3-indolyl phosphate in the presence of Nitro blue tetrazolium. Histochemical studies on unfixed cryostat sections indicate that this type of alkaline phosphatase is restricted to discrete regions in the cockroach brain. Highest enzyme activity is encountered in the mushroom bodies, central body, antennal glomeruli and specific parts of some distinct neural connections including the optic nerve, antennal nerve, circumoesophageal connectives and nerves leaving the suboesophageal ganglion. Tissue fixation by use of formaldehyde-type fixatives, as well as routine paraffin-embedding, completely destroy all histochemically detectable enzyme activity.Native polyacrylamide gradient electrophoresis suggests that the alkaline phosphatase activity is present as multiple isozymic forms, which show up in the 120–130 kD range of standard proteins. Enzyme activity becomes undetectable after fixation (trichloroacetic acid, formaldehyde containing fixatives) of electrophoretically separated native proteins, as well as after electrophoresis in denaturing conditions (SDS and -mercapto-ethanol, boiling). However, the enzyme activity remains virtually unaffected after storage of the sample for prolonged periods at –20 to –80°C.     

Electron microscope observations on the salivary gland of the cockroach,Periplaneta americana

Summary The salivary gland of the cockroach was studied with the electron microscope. Structural modifications of the cells comprising the duct system as well as the fine structure of the cells comprising the secretory tissue have been characterized. An attempt is made to correlate certain of the structural features with functional significance.This investigation was supported by grants (RG-9230, 4706, 5479) from the National Institutes of Health and a grant (G-9879) from the National Science Foundation.     

Further purification and characterization of trehalases from the American cockroach,Periplaneta americana

Summary A soluble trehalase was purified more than 200-fold from the male accessory gland of the American cockroach,Periplaneta americana, by CM-cellulose, hydrophobic chromatography, and Sephacryl S-200 gel filtration. The final preparation was homogeneous as judged by polyacryl-amide gel electrophoresis in the absence and presence of SDS, isoelectric focusing, and immuno-diffusion tests. The purified enzyme was maximally active at pH 5.2, and showed high specificity for trehalose with aK _m of 0.98 mM. The isoelectric point was 4.7. The molecular weight of the enzyme (75,000) was determined by molecular sieve chromatography and SDS-polyacrylamide gel electrophoresis. The amino acid composition was determined and compared with those of trehalases purified from other sources. The trehalase could be stained for carbohydrate with the periodic acid-Schiff's reagent following SDS-polyacrylamide gel electrophoresis, indicating that it was a glycoprotein. Another soluble trehalase and two types of fat body trehalases could be highly purified by the method described. A comparison of the properties of trehalases from the accessory gland and the fat body showed some resemblance.     

Certain functional connections of neurons control the walking of the cockroach Periplaneta americana

On isolated abdominal nervous chain of the cockroach studies have been made of the responses of motoneurones of the thoracic ganglion to electrical stimulation of afferent axons of the leg nerve under normal conditions and during application of an anticholinesterase drug, GD-7. Depending on the type of stimulated axons, monosynaptic response, as well as polysynaptic phasic and tonic responses of motoneurones were recorded. A scheme of activation of motoneurones is suggested which evokes slow contractions of muscles in cockroach extremities.     

The role of antennal hair plates in object-guided tactile orientation of the cockroach (Periplaneta americana)

The searching behavior of blinded cockroaches was examined under unrestrained conditions, in an arena, and on a treadmill. When cockroaches searching in a circular arena touched a stationary object (metal pole) with their antennae, they frequently approached the object more closely, and then climbed up it. Similar orientation behavior was observed in tethered animals in open loop conditions, walking on a Styrofoam ball. In these restrained cockroaches, a single antenna sufficed to distinguish the angular positions of an object, in the horizontal plane (0 degrees, 45 degrees, and 90 degrees). A group of mechanosensitive hairs on the basal segment of the antenna (scapal hair plate) appears to play a major role in antennal object detection in the horizontal plane, as gauged by shaving off these scapal hair plates. In unrestrained cockroaches, shaving the scapal hair plate increased the time needed to approach an object. Under tethered conditions, the ability to turn towards and to establish antennal contact with a test object was significantly impaired.