Supravital Methylene Blue Staining of Piloneural Complexes of Common Fur Hair Follicles in the Rat

Light microscopic observations employing supravital methylene blue staining are presented for piloneural complexes of common fur hairs in the mystacial pad of the rat snout. The investigation revealed anatomical details of piloneural complexes belonging to follicles of both vellus and guard hairs. In the methylene blue stained preparations, different types of palisade-like lanceolate nerve fiber endings could be discriminated. The thicker vellus and thinner guard hairs (hair diameter: 15-25 μm) exhibited a different innervation pattern compared to the thicker guard hairs, and two subtypes of piloneural complexes could be distinguished. Both subtypes were characterized by slightly stained lanceolate endings and the absence of a circular nerve fiber plexus. One subtype, however, showed strongly stained spines originating from the lanceolate endings. A few spines of adjacent lanceolate endings appeared in contact with each other. In the second subtype, these spines were replaced by anastomoses suggesting a delicate terminal nerve fiber network. The moderately stained lanceolate endings located primarily at the follicles of thicker guard hairs (hair diameter: 30-40 μm) showed smooth outlines, but were characterized by the occurrence of an intensely stained additional circular nerve fiber plexus. The differences in the morphology of piloneural complexes associated with the follicles of common fur hairs suggest differences regarding their mechanoreceptive tasks.     

Ultrastructure of the antennal sensilla of the cockroach-egg parasitoid,Tetrastichus hagenowii (Hymenoptera: Eulophidae)

Eggs of a number of cockroach species are parasitized by Tetrastichus hagenowii. The ultrastructure of the sensilla on the antennae of females and males was examined by scanning and transmission electron microscopy. The females have two types of multiporous plate sensilla while the males have only one. Type 1 is found in females and males and has a relatively thin cuticular wall and many pores, while type 2 is found only in females and has a relatively thick cuticular wall and few pores. Both sexes have nonporous, thick-walled, socketed hairs; multiporous, nonsocketed hairs; multiporous, thick-walled pegs; and terminal hairs. In addition, males have multiporous, nonsocketed, long hairs. The sensilla are similar, in many respects, to the sensilla of other chalcid parasitoids. The antennal sensilla of female T. hagenowii are probably involved in ovipositional behavior. The multiporous, long hairs of the male possibly receive stimuli during mating behavior A chemoreceptive function is proposed for the multiporous plate sensilla.     

Supravital Methylene Blue Staining of Piloneural Complexes of Common Fur Hair Follicles in the Rat

Light microscopic observations employing supravital methylene blue staining are presented for piloneural complexes of common fur hairs in the mystacial pad of the rat snout. The investigation revealed anatomical details of piloneural complexes belonging to follicles of both vellus and guard hairs. In the methylene blue stained preparations, different types of palisade-like lanceolate nerve fiber endings could be discriminated. The thicker vellus and thinner guard hairs (hair diameter: 15-25 μm) exhibited a different innervation pattern compared to the thicker guard hairs, and two subtypes of piloneural complexes could be distinguished. Both subtypes were characterized by slightly stained lanceolate endings and the absence of a circular nerve fiber plexus. One subtype, however, showed strongly stained spines originating from the lanceolate endings. A few spines of adjacent lanceolate endings appeared in contact with each other. In the second subtype, these spines were replaced by anastomoses suggesting a delicate terminal nerve fiber network. The moderately stained lanceolate endings located primarily at the follicles of thicker guard hairs (hair diameter: 30-40 μm) showed smooth outlines, but were characterized by the occurrence of an intensely stained additional circular nerve fiber plexus. The differences in the morphology of piloneural complexes associated with the follicles of common fur hairs suggest differences regarding their mechanoreceptive tasks.     

Chiton integument: Ultrastructure of the sensory hairs of Mopalia muscosa (Mollusca: Polyplacophora)

Summary The dorsal integument of the girdle of the chiton Mopalia muscosa is covered by a chitinous cuticle about 0.1 mm in thickness. Within the cuticle are fusiform spicules composed of a central mass of pigment granules surrounded by a layer of calcium carbonate crystals. Tapered, curved chitinous hairs with a groove on the mesial surface pass through the cuticle and protrude above the surface. The spicules are produced by specialized groups of epidermal cells called spiniferous papillae and the hairs are produced by trichogenous papillae. Processes of pigment cells containing green granules are scattered among the cells of each type of papilla and among the common epidermal cells.The wall or cortex of each hair is composed of two layers. The cortex surrounds a central medulla that contains matrix material of low density and from 1 to 20 axial bundles of dendrites. The number of bundles within the medulla varies with the size of the hair. Each bundle contains from 1 to 25 dendrites ensheathed by processes of supporting cells. The dendrites and supporting sheath arise from epidermal cells of the central part of the papilla. At the base of each trichogenous papilla are several nerves that pass into the dermis. Two questions remain unresolved. The function of the hairs is unknown, and we have not determined whether the sensory cells are primary sensory neurons or secondary sensory cells.     

EPIDERMAL FEATURES AND SILICA DEPOSITION IN LEMMAS AND AWNS OF ZIZANIA (GRAMINEAE)

In four species of Zizania (Gramineae: Oryzeae) epidermal features of pistillate and staminate lemmas, paleas, and awns were studied by scanning electron microscopy (SEM) and energy dispersive X-ray analysis. Features observed were silica bodies, siliceous papillae, pitted siliceous papillae, stomata, microhairs, and prickle hairs. Staminate lemmas have all of these features. Pistillate lemmas have silica bodies and prickle hairs, lack stomata, and differ among species in occurrences of microhairs and siliceous papillae and pitted siliceous papillae. Awns of pistillate lemmas have silica bodies, prickle hairs, microhairs, and stomata; therefore, they possess a more complete set of features than their attached lemmas. Shapes of silica bodies on pistillate lemmas differ among species. A taxonomic key based on SEM observation of pistillate lemmas separates the four species by the shapes of silica bodies, arrangement of prickle hairs, and occurrences of microhairs and siliceous papillae. The main silica-containing structures are silica bodies, siliceous papillae, pitted siliceous papillae, and to a lesser extent prickle hairs. Pitted siliceous papillae with circular raised rims are formed by collapse or exfoliation of the tops of siliceous papillae; these have not been previously described in grasses. Comparison of epidermal features in the lemmas and leaves of Zizania shows that the former lack three kinds of nonsilicified papillae and epicuticular wax that are present on the latter but the lemmas have siliceous papillae and pits that are absent in leaves.     

Anatomical organization of antennal-lobe glomeruli in males and females of the scarab beetle Holotrichia diomphalia (Coleoptera: Melolonthidae)

The glomerular organization of the primary olfactory brain center, the antennal lobe, was studied in males and females of Holotrichia diomphalia adults using serial histological sections labeled by the reduced silver-stain technique. The results revealed an apparent sexual dimorphism. Whereas an enlarged cap-shaped glomerulus was found at the antennal nerve entrance into the antennal lobe in males, no such unit was present in females. Also the size of the antennal lobe differed between the sexes, the antennal lobe of males being larger than that of females. We estimated the total number of glomeruli at approximately 60 units in the female antennal lobe. In males, we could discriminate only those glomeruli that were located in the anterior area of the antennal lobe.     

The skin of primates. XLI. The skin of the silver marmoset—Callithrix (= Mico) Argentata

The skin of the silver marmoset, Callithrix (= Mico) argentata Linnaeus, has many outstanding characteristics. The unusually thin epidermis and dermis are generally devoid of melanotic melanocytes. The surface of the interramal gular region is peppered with small, elevated papillae; that of the corpus penis is characterized by keratinized, proximally directed hollow spines in whose cavities are organized nerve end-organs and capillary loops. Cholinesterase-reactive papillary nerve end-organs and Meissner corpuscles populate all volar friction surfaces. A highly vascular dermis and subcutaneous fat pad partially contribute to the characteristic rubicund color of the face, external ears, and anogenital region. Many body surface hairs are accompanied by the classic Haarscheibe of Pinkus. Sinus hairs are plentiful; a circumscribed vibrissa-bearing eminence is located on the ventral ulnar aspect of each wrist. Alkaline phosphatase-positive, stellate-shaped cells are found on the outer root sheath and epithelial sac of active and quiescent hairs in all cephalic regions; such cells are not argyrophilic, aurophilic, or osmiophilic. Hairs grow in linear perfect sets of 3 to 5 follicles; they do not grow singly on the cheek. Large sebaceous glands contain alkaline phosphatase in their peripheral acini; extensive fields of gigantic multilobular sebaceous glands contribute to the distinct, opaque-white color of the scrotal skin. Numbers of apocrine sweat glands are diminished in cephalic regions but one gland occurs with each hair follicle in the axilla, scrotum, suprapubic region, and ulnar eminence. Relatively avascular eccrine sweat glands are confined to the volar friction surfaces. Their secretory coils contain sporadically distributed glycogen and phosphorylase and surrounding nerves are much more reactive for acetyl- than butyrylcholinesterase.     

Inter- and intra-specific differences in the number of larval instars in British populations of 24 species of stoneflies (Plecoptera)

1. Ontogenetic changes during the life cycle of aquatic insects are important not only in life‐history studies but also in evaluating food‐web structure. They require information on the growth and number of larval instars but such information is lacking for many species, including Plecoptera. Therefore, the chief objectives of the present study were to determine inter‐ and intra‐specific differences in the number of larval instars in British populations of 24 species of stoneflies, to test Dyar’s hypothesis that growth followed a geometric progression, and to synthesise this information with previously published values for four British species. 2. Larvae were reared at constant temperatures in the laboratory from eggs from 63 populations (one to six populations per species). First instars from each population were divided into three batches and each batch was reared at one of three constant temperatures. For each species, the rearing temperature and source population had no significant effect on the mean size of each larval instar. 3. The relationship between the geometric mean length of each instar and instar number was well described by an exponential equation (P < 0.001, r² > 0.9 for all species), thus supporting Dyar’s hypothesis. Only one species, Brachyptera risi, had the same number of instars for males and females (12–13). For the other 15 herbivorous species and the four smaller carnivorous ones, the number of instars was higher for females than males (range 11–16 for males, 12–17 for females). The larger size of the females was due to their additional instars, not a sex difference in growth rates. In contrast, there was a clear growth separation of the sexes after the 9th or 10th instar for the four largest carnivores. The number of larval instars was highest for these four species (range 16–19 for males, 18–23 for females), and females were much larger than males. 4. A multiple regression equation with data from the present and previous studies (n = 27) showed that variability in the mean length of the first instar and the maximum number of larval instars for each species accounted for 88% and 91% of the variability in the mean length of the final instar for males and females, respectively. 5. Values for Plecoptera in other countries were in general agreement with those in the present study, especially in the same families. Two old, but widely quoted, high values are doubtful. The present study and four previous ones provide a sound basis for ontogenetic studies on 28 species of Plecoptera and their role in aquatic ecosystems.     

Sexual dimorphism in neuronal projections from the antennae of silk moths (Bombyx mori,Antheraea polyphemus) and the gypsy moth (Lymantria dispar)

Summary The antennal lobe of both sexes of the silk moth Bombyx mori contains 55–60 ventrally located antennal glomeruli; in addition, that of the male contains a dorsal macroglomerular complex (MGC). A group of identifiable glomeruli consisting of two lateral large glomeruli (LLG) and four medial small glomeruli (MSG) is present in both sexes, but the LLG are greatly enlarged in the female. A MGC is also present in the male gypsy moth Lymantria dispar and male giant silk moth Antheraea polyphemus. The MGC in all of these species is organized into 3–4 distinct levels of glomeruli. Antennal sensory fibers were stained by cobalt backfills in B. mori, A. polyphemus, and L. dispar. Most fibers stained from cut long hairs (sensilla trichodea) projected to MGC in males and LLG in both sexes of B. mori. The distribution of fibers in the MGC of B. mori was topographically biased in that a majority of fibers from anterior branches projected medially in MGC while most fibers from posterior branches projected laterally or anteriorly. Terminal arborizations of single fibers were each restricted to a single glomerular level of the MGC. Fibers projecting to the posterior antennal center were frequently stained in cut-hair and control preparations, apparently by uptake of cobalt through intact sensilla on flagellar branches.     

Social organization of white‐headed langurs (Trachypithecus leucocephalus) in the Nongguan Karst Hills,Guangxi, China

The number of males per group is the most variable aspect of primate social organization and is often related to the monopolizability of females, which is mainly determined by the number of females per group and their reproductive synchrony. Colobines show both inter‐specific and intra‐specific variations in the number of males per group. Compared with other colobine species, little is known about the social organization of white‐headed langur (Trachypithecus leucocephalus), despite its endangered status and unusual limestone habitat. As a part of a long‐term study of the white‐headed langurs in the Nongguan Karst Hills, Guangxi, China, we quantitatively investigated their social organization by analyzing census data from 1998 to 2003. The population censuses revealed that the predominant social organization of bisexual groups was the one‐male group, similar to a previous report on this species and many other Asian colobines. In such groups, one adult male associated with 5.1 adult females, 0.1 sub‐adult males, 2.6 juveniles and 2.9 infants on average, with a mean group size of 11.7 individuals. In addition, three multi‐male groups were recorded, consisting of 2–3 adult males, 1–5 adult females, 0–2 sub‐adult males, 0–7 juveniles and 0–2 infants. They did not contain more adult females than the one‐male groups and were unstable in group membership. The langurs outside bisexual groups were organized into small nonreproductive groups or lived as solitaries. The nonreproductive groups averaged 1.3 adult males, 1.3 sub‐adult males and 2.6 juveniles. Juvenile females were present in such groups on 52.4% of all occasions. As predicted by the monopolization model, the prevalence of the one‐male pattern in this species may mainly be attributed to the small number of females in the group. The possible reasons for the occurrence of multi‐male groups and the presence of juvenile females in nonreproductive groups are also discussed. Am. J. Primatol. 71:206–213, 2009. © 2008 Wiley‐Liss, Inc.     

Adhesive Papillae of Phallusia mamillata Larvae: Morphology and Innervation

The swimming larvae of most solitary ascidians belonging to the Ascidiidae family bear three anterior, simple conic adhesive papillae. They secrete adhesive substances that are used to effect transitory settlement at the beginning of the metamorphosis.The adhesive papillae of newly hatched Phallusia mamillata larvae examined by the SEM are covered by the tunic. When the larvae are about to settle, the tunic becomes fenestrated over the central part of the papilla and bulb-ended microvilli protrude through the holes. These papillae have two types of elongated cells: many peripheral cells and few larger central cells with microvilli and bundles of microtubules oriented along the major axis of the cells.We have done immunofluorescence experiments with an anti-beta-tubulin monoclonal antibody (clone 2-28-33) reacting with axonal microtubules. Only the central cells of the papillae were stained and the axons appeared to arise from the proximal ends of these cells. These axons form a long nerve that reaches the brain vesicle. Branches of the same nerve appear to connect to the basal ends of the peripheral cells. By confocal laser microscopy we were able to follow the course of the papillary nerve. The two nerves connecting the dorsal papillae fuse together into a single nerve that runs posteriorly. The nerve connecting the ventral papilla runs posteriorly for a long tract before fusing with the nerve of the dorsal papillae just near the brain.The reported observations raise the hypothesis that the central cells of the adhesive papillae might be primary sensory neurons and that they may have chemosensory function.     

A note on the hairy achenes of four African species of Scleria Bergius (Cyperaceae)

Surface features of hirsute achenes of four African species of Scleria have been examined by SEM. All bear unicellular, terete hairs with swollen bases. As the achenes mature and dry, the hairs collapse, except for their partly silicified bases, which appear as pit-like depressions from which the now-flattened hairs emerge. If the achene surface is not smooth the hairs are localized on the interlacunar ridges. In addition to the hairs, three of the four species examined show minute papillate protuberances from the silicified outer tangential walls of the epidermal cells. These papillae form a further ornamentation to the achenes visible only at high magnification. The fourth species entirely lacks these papillae.     

Fine Structure of Cephalic Sense Organs in Meloidogyne incognita Males

Amphids, and the cephalic and labial papillae of Meloidogyne incognita males were examined in detail by electron microscopy. Each amphid basically consists of an amphidial gland, a nerve bundle and an amphidial duct. The gland is a broad microvillous organ with a narrow anterior process, which is closely associated with the amphidial duct. A posterior process of the gland contains secretory organelles and proceeds along the esophagus with the lateral cephalic nerve bundle. The nerve bundle penetrates the broad portion of the gland and, subsequently, individual nerve processes (dendrites) separate from one another, thus forming the sensilla pouch which is enveloped by the gland. Anterior to the pouch, the dendrites converge as they enter and eventually terminate in the amphidial duct. The external opening of the duct is a broad slit which separates the cheek, the outermost part of the lateral lip, from the remainder of the lip region. M. incognita males have six inner labial papillae and four outer cephalic papillae which are each innervated by two and one cilia, respectively. In labial papillae, the cilia appear to terminate at the base of a pore opening, whereas in cephalic papillae each cilium terminates beneath the labial cuticle.     

Expression of chemosensory proteins in hairs on wings of Locusta migratoria (Orthoptera: Acrididae)

The hairs on the wings of Locusta migratoria were observed and mapped using light microscopy, as well as by scanning and transmission electron microscopy. Based on their ultrastructure, we can distinguish four main types of hairs on the wings of adult L. migratoria , viz, short, medium and long hairs, and sensilla chaetica. The long hairs are located only on the ventral surface of the hindwing, whereas the other three types are present both on the dorsal and ventral surfaces of forewing and hindwing in both sexes. Medium hairs and sensilla chaetica are significantly more abundant on the dorsal surface of forewings in both females and males, than on the ventral surface, whereas the opposite was observed for short hairs (P < 0.01). No significant difference between males and females was observed in the density of any type of hairs (P > 0.1). Several dendritic branches, enveloped by a dendrite sheath, are situated in the lymph cavity of sensilla chaetica. Instead, no dendritic structure was observed in the cavity of the other three types of hairs. Immunocytochemical localization of chemosensory proteins (CSPs) was performed on ultrathin sections of hairs on wings. The antiserum against chemosensory proteins from L. migratoria (LmigCSP-II) strongly labelled sensilla chaetica, with gold granules only found in the outer sensillum lymph. In addition, the epidermal cell membrane of the wing was stained by the antiserum against LmigCSP-II. The other three types of hairs were never labelled. The results indicate that the wings might involve in contact chemoreception process.     

Study of h-TSH immunoreactive adenohypophyseal cells following treatment with methymazole

The TSH-producing adenohypohyseal cells of Wistar rats were studied after treatment with orally administered methymazole by the PAP immunocytochemical method. These cells were compared with those of normal animals. The effects of methymazole were different in the females to those observed in males. In both sexes, the numerical density (number of TSH cells per 1000 microns 2) increased after treatment. The cellular and cytoplasmic areas increased in the females while they decreased in the males. The nuclear area and the nuclear area/cytoplasmic area ratio increased in the males and decreased in the females following treatment with methymazole. This treatment caused the appearance of large, intensely stained cells, with an eccentric nucleus and cytoplasmic processes accompanied by weakly stained cells that were situated close to blood vessels.     

Hormone accumulation in song regions of the canary brain

[³H]Testosterone (T) was injected into male and female canaries (Serinus canarius), a species in which females are able to sing but do so more rarely and more simply than males. Autoradiographic analysis revealed that males and females have equal proportions of cells labeled by T or its metabolites in four song control nuclei: the high vocal center (HVC), the lateral portion of the magnocellular nucleus of the anterior neostriatum (IMAN), the robust nucleus of the archistriatum (RA), and the hypoglossal motor nucleus (nXII). Labeled cells were also observed in both sexes in the medial portion of MAN, and in hypothalamic nuclei. In both sexes, labeled cells in HVC, IMAN, RA, and nXII were larger than unlabeled cells. There were no sex differences in the size of either labeled or unlabeled cells in these song nuclei. The density of labeled cells per unit volume of tissue did not differ between the sexes in any song nucleus analyzed. However, because males have larger HVC and RA than females, males have a greater total number of hormone-sensitive cells in these regions than do females. Comparison of these results with measures of hormone accumulation in zebra finches and tropical duetting wrens suggests that the complexity of song that a bird can produce is correlated with the total number of hormone-sensitive cells in song nuclei. © 1992 John Wiley & Sons, Inc.     

Addendum to the Morphology of Steinernema scapterisci

This paper provides additional information on the morphology of Steinernema scapterisci. For females, the amphids are shown for the first time, and clearer scanning electron microscope (SEM) photographs of the six labial and four cephalic papillae are presented. For males, six labial and four cephalic papillae, one or two pairs of additional genital papillae, and the death shape are shown. For infective juveniles, six labial and four cephalic papillae and an elevated oral disc are shown.     

The fine structure of the buccal tentacles of Holothuria forskali (Echinodermata,Holothuroidea)

Summary Ultrastructural study of the buccal tentacles of Holothuria forskali revealed that each tentacle bears numerous apical papillae. Each papilla consists of several differentiated sensory buds.The epidermis of the buds is composed of three cell types, i.e. mucus cells, ciliated cells, and glandular vesicular cells (GV cells). The GV cells have apical microvilli; they contain bundles of cross striated fibrillae associated with microtubules. Ciliated cells have a short non-motile cilium. Bud epidermal cells intimately contact an epineural nervous plate which is located slightly above the basement membrane of the epidermis. The epineural plate of each bud connects with the hyponeural nerve plexus of the tentacle. This nerve plexus consists of an axonic meshwork surrounded in places by sheath cells. The buccal tentacles have well-developed mesothelial muscles. Direct innervation of these muscles by the hyponeural nerve plexus was not seen.It is suggested that the buccal tentacles of H. forskali are sensory organs. They would recognize the organically richest areas of the sediment surface through the chemosensitive abilities of their apical buds. Tentacles presumably trap particles by wedging them between their buds and papillae.     

Structural features of <Emphasis Type="Italic">Rhododendron luteum</Emphasis> flower

The flower of Rhododendron luteum (L.) Sweet has a pentamerous structure with radial symmetry. The anthers filament surface is covered by dense non-glandular hairs to the half of the height. The tubular anther dehisces along creating two openings in the anther-sac walls and the viscous pollen is released through two splits along the anther lobes. The pistil is pentamerous and the axial channel is filled with a mucilaginous secretion product which is continuous with the exudate on the stigma surface. The stigmatic papillae are densely packed and their exudate is stained intensively red for carbohydrates, while pollen grains are stained positively for lipids. The five-locular ovary has isomerous carpels (syncarpous gynoecium) and the ovary surface is covered by numerous, densely-packed glandular and non-glandular hairs protecting the nectar against transpiration. Numerous ovules per locule occur with one integument and a thin-walled megasporiangium. In carpels, oil cells occur sporadically as solitary idioblasts, located around the vascular bundles. Transmitting tissue cells contain a large central, electron translucent vacuole, filling most of the cell containing dark osmiophilic bodies homogenous or granular in appearance.     

Fine Structure of Cephalic Sense Organs in Heterodera glycines Males

Cephalic sense organs of Heterodera glycines males were examined in detail by electron microscopy. Each amphid basically consists of an amphidial gland, a nerve bundle, and an amphidial duct. The amphidial gland consists of a microvillous region, and laterally is closely associated with a large secretory cell. The nerve bundle penetrates the microvillous region, and further anteriorly individual nerve processes (dendrites) separate from one another, thus forming a sensilla pouch which is enveloped by the microvillous region of the gland. Anterior to the pouch, the cilia-like dendrites converge as they enter and eventually terminate in the amphidial duct. Heterodera glvcines males have the innervation basis for a full complement of sixteen papillae, although surface manifestations are present for only six minute inner labial papillae. In addition, four outer labial and four cephalic receptors terminate beneath the surface, and another two dendrite pairs end further posteriorly beneath the basal plate of the cephalic framework. Papillary receptors which terminate beneath the surface are probably mechanoreceptive, whereas inner labial papillae have pore-like openings to the exterior and may be chemoreceptive. Amphids and papillae of H. glycines are fundamentally similar to those of Meloidogyne incognita, although certain striking differences exist.