Posterior Dorsal Region Research Articles

Prediction of subthalamic stimulation efficacy on isolated dystonia via support vector regression

IntroductionDeep brain stimulation (DBS) of subthalamic nucleus (STN) has been well-established and increasingly applied in patients with isolated dystonia. Nevertheless, the surgical efficacy varies among patients. This study aims to explore the factors affecting clinical outcomes of STN-DBS on isolated dystonia and establish a well-performed prediction model. MethodsIn this prospective study, thirty-two dystonia patients were recruited and received bilateral STN-DBS at our center. Their baseline characteristics and up to one-year follow-up outcomes were assessed. Implanted electrodes of each subject were reconstructed with their contact coordinates and activated volumes calculated. We explored correlations between distinct clinical characteristics and surgical efficacy. Those features were then trained for the model in outcome prediction via support vector regression (SVR) algorithm and testified through cross-validation. ResultsPatients demonstrated an average clinical improvement of 56 ± 25 % after STN-DBS, significantly affected by distinct symptom forms and activated volumes. The optimal targets and activated volumes were concentratedly located at the dorsal posterior region to STN. Most patients had a rapid response to STN-DBS, and their motor score improvement within one week was highly associated with long-term outcomes. The trained SVR model, contributed by distinct weights of features, could reach a maximum prediction accuracy with mean errors of 11 ± 7 %. ConclusionSTN-DBS demonstrated significant and rapid therapeutic effects in patients with isolated dystonia, by possibly affecting the pallidofugal fibers. Early improvement highly indicates the ultimate outcomes. SVR proves valid in outcome prediction. Patients with predominant phasic and generalized symptoms, shorter disease duration, and younger onset age may be more favorable to STN-DBS in the long run.

Phenotypic integration in the carnivoran backbone and the evolution of functional differentiation in metameric structures.

Explaining the origin and evolution of a vertebral column with anatomically distinct regions that characterizes the tetrapod body plan provides understanding of how metameric structures become repeated and how they acquire the ability to perform different functions. However, despite many decades of inquiry, the advantages and costs of vertebral column regionalization in anatomically distinct blocks, their functional specialization, and how they channel new evolutionary outcomes are poorly understood. Here, we investigate morphological integration (and how this integration is structured [modularity]) between all the presacral vertebrae of mammalian carnivorans to provide a better understanding of how regionalization in metameric structures evolves. Our results demonstrate that the subunits of the presacral column are highly integrated. However, underlying to this general pattern, three sets of vertebrae are recognized as presacral modules-the cervical module, the anterodorsal module, and the posterodorsal module-as well as one weakly integrated vertebra (diaphragmatic) that forms a transition between both dorsal modules. We hypothesize that the strength of integration organizing the axial system into modules may be associated with motion capability. The highly integrated anterior dorsal module coincides with a region with motion constraints to avoid compromising ventilation, whereas for the posterior dorsal region motion constraints avoid exceeding extension of the posterior back. On the other hand, the weakly integrated diaphragmatic vertebra belongs to the "Diaphragmatic joint complex"-a key region of the mammalian column of exceedingly permissive motion. Our results also demonstrate that these modules do not match with the traditional morphological regions, and we propose natural selection as the main factor shaping this pattern to stabilize some regions and to allow coordinate movements in others.

Identifying geographically differentiated features of Ethopian Nile tilapia (Oreochromis niloticus) morphology with machine learning.

Visual characteristics are among the most important features for characterizing the phenotype of biological organisms. Color and geometric properties define population phenotype and allow assessing diversity and adaptation to environmental conditions. To analyze geometric properties classical morphometrics relies on biologically relevant landmarks which are manually assigned to digital images. Assigning landmarks is tedious and error prone. Predefined landmarks may in addition miss out on information which is not obvious to the human eye. The machine learning (ML) community has recently proposed new data analysis methods which by uncovering subtle features in images obtain excellent predictive accuracy. Scientific credibility demands however that results are interpretable and hence to mitigate the black-box nature of ML methods. To overcome the black-box nature of ML we apply complementary methods and investigate internal representations with saliency maps to reliably identify location specific characteristics in images of Nile tilapia populations. Analyzing fish images which were sampled from six Ethiopian lakes reveals that deep learning improves on a conventional morphometric analysis in predictive performance. A critical assessment of established saliency maps with a novel significance test reveals however that the improvement is aided by artifacts which have no biological interpretation. More interpretable results are obtained by a Bayesian approach which allows us to identify genuine Nile tilapia body features which differ in dependence of the animals habitat. We find that automatically inferred Nile tilapia body features corroborate and expand the results of a landmark based analysis that the anterior dorsum, the fish belly, the posterior dorsal region and the caudal fin show signs of adaptation to the fish habitat. We may thus conclude that Nile tilapia show habitat specific morphotypes and that a ML analysis allows inferring novel biological knowledge in a reproducible manner.

Nodular lesion on the posterior dorsal surface of the tongue

A 47-year-old man was referred to the Oral Medicine Service of our institution complaining of discomfort during eating and speaking because of the presence of a painless nodule on the posterior dorsal surface of the tongue. The patient had noticed the tongue lesion 1 month ago, and it had gradually expanded until it reached the size seen in the current clinical presentation. The medical history was noncontributory. Intraoral examination revealed a pink, pedunculated, exophytic, well-defined nodule, with a discretely lobulated and substantial ulcerated surface covered by a yellowish pseudomembrane without any tendency to bleed; measuring approximately 2 cm in greatest diameter; and located on the posterior dorsal region of the tongue (Figure 1).

A morphometric comparison of the parietal lobe in modern humans and Neanderthals

The modern human brain and braincase have a characteristic globular shape including parietal and cerebellar bulging. In contrast, Neanderthals, although having similar endocranial volume, displayed more elongated endocrania with flatter parietal and cerebellar regions. Based on endocranial imprints, we compare the parietal lobe morphology of modern humans and Neanderthals, as this brain region is central to several cognitive functions including tool use and visual imaging. In paleoneurology, shape analyses of endocasts are based either on anatomical landmarks that represent endocranial surface features homologous to cortical convolutions (impressions of brain gyri and sulci) or on dense meshes of semilandmarks that capture overall endocranial shape. Previous analyses using the former suggested that modern humans have relatively longer and taller parietal lobes than extinct human species, while the latter emphasized parietal bulging without a significant size difference of parietal regions. In the present study, we combine both anatomical landmarks and surface semilandmarks to investigate the morphological differences of the parietal lobes between modern humans and Neanderthals. Despite limitations by landmark uncertainty, our analyses were able to detect and confirm average different parietal shapes, with modern humans displaying taller and anteroposteriorly extended parietal lobes. We also show mean size differences, with modern humans displaying slightly larger surface areas on the dorsal posterior parietal region, and on a lateral region comprising the supramarginal gyrus, angular gyrus, and intraparietal sulcus. While we observed average differences in the parietal form between the two species, their ranges of distribution overlap, indicating the differences could be a matter of degree. Thus, further analyses on intraspecific variation in parietal lobe morphology within modern human brains should help understand the differences between globular and elongated endocrania. This is crucial because changes to the parietal cortex might affect associative and integrative functions between somatic and visual primary inputs.

Immunohistochemical and Direct Mass Spectral Analyses of Plautia stali Myoinhibitory Peptides in the Cephalic Ganglia of the Brown-Winged Green Bug Plautia stali.

For seasonal adaptation, the brown-winged green bug Plautia stali (Hemiptera: Pentatomidae) enters reproductive diapause by suppressing juvenile hormone biosynthesis. Plautia stali myoinhibitory peptides (Plast-MIPs) are known to have allatostatic effects and to suppress juvenile hormone biosynthesis. We examined Plast-MIP-producing neurons in the brain with immunohistochemistry and Fourier transform ion cyclotron resonance mass spectrometry. Rabbit polyclonal antiserum against Plast-MIP revealed immunoreactive cells in seven regions of the brain, including the posterior antennal lobe, basal optic lobe, dorsal anterior protocerebrum, ventrolateral protocerebrum, pars intercerebralis, posterior protocerebrum, and dorsal posterior region to the calyx of the mushroom body, aside from the gnathal ganglion. Anatomical locations of the immunoreactive cells in the pars intercerebralis and dorsal posterior region to the mushroom body calyx partly overlapped with the cell body location stained by retrograde dye fills from the corpus allatum and corpus cardiacum complex. Direct mass spectrometry revealed the molecular ion peaks corresponding to the predictive mass of Plast-MIPs in the pars intercerebralis and the corpus allatum-corpus cardiacum complex. Plast-MIP immunoreactivity in different cell types suggests that Plast-MIPs have different functions in the cephalic ganglia. Considering the anatomical location of neurons projecting to the corpus allatum-corpus cardiacum and results of mass spectrometry, Plast-MIP immunoreactive cells in the pars intercerebralis may play a role in suppressing juvenile hormone biosynthesis.

The large-scale organization of shape processing in the ventral and dorsal pathways.

Although shape perception is considered a function of the ventral visual pathway, evidence suggests that the dorsal pathway also derives shape-based representations. In two psychophysics and neuroimaging experiments, we characterized the response properties, topographical organization and perceptual relevance of these representations. In both pathways, shape sensitivity increased from early visual cortex to extrastriate cortex but then decreased in anterior regions. Moreover, the lateral aspect of the ventral pathway and posterior regions of the dorsal pathway were sensitive to the availability of fundamental shape properties, even for unrecognizable images. This apparent representational similarity between the posterior-dorsal and lateral-ventral regions was corroborated by a multivariate analysis. Finally, as with ventral pathway, the activation profile of posterior dorsal regions was correlated with recognition performance, suggesting a possible contribution to perception. These findings challenge a strict functional dichotomy between the pathways and suggest a more distributed model of shape processing.

SIK3–HDAC4 signaling regulates Drosophila circadian male sex drive rhythm via modulating the DN1 clock neurons

The physiology and behavior of many organisms are subject to daily cycles. In Drosophila melanogaster the daily locomotion patterns of single flies are characterized by bursts of activity at dawn and dusk. Two distinct clusters of clock neurons-morning oscillators (M cells) and evening oscillators (E cells)-are largely responsible for these activity bursts. In contrast, male-female pairs of flies follow a distinct pattern, most notably characterized by an activity trough at dusk followed by a high level of male courtship during the night. This male sex drive rhythm (MSDR) is mediated by the M cells along with DN1 neurons, a cluster of clock neurons located in the dorsal posterior region of the brain. Here we report that males lacking Salt-inducible kinase 3 (SIK3) expression in M cells exhibit a short period of MSDR but a long period of single-fly locomotor rhythm (SLR). Moreover, lack of Sik3 in M cells decreases the amplitude of PERIOD (PER) cycling in DN1 neurons, suggesting that SIK3 non-cell-autonomously regulates DN1 neurons' molecular clock. We also show that Sik3 reduction interferes with circadian nucleocytoplasmic shuttling of Histone deacetylase 4 (HDAC4), a SIK3 phosphorylation target, in clock neurons and that constitutive HDAC4 localization in the nucleus shortens the period of MSDR. Taking these findings together, we conclude that SIK3-HDAC4 signaling in M cells regulates MSDR by regulating the molecular oscillation in DN1 neurons.

Identification and evolutionary analysis of long non-coding RNAs in zebra finch

BackgroundLong non-coding RNAs (lncRNAs) are important in various biological processes, but very few studies on lncRNA have been conducted in birds. To identify IncRNAs expressed during feather development, we analyzed single-stranded RNA-seq (ssRNA-seq) data from the anterior and posterior dorsal regions during zebra finch (Taeniopygia guttata) embryonic development. Using published transcriptomic data, we further analyzed the evolutionary conservation of IncRNAs in birds and amniotes.ResultsA total of 1,081 lncRNAs, including 965 intergenic lncRNAs (lincRNAs), 59 intronic lncRNAs, and 57 antisense lncRNAs (lncNATs), were identified using our newly developed pipeline. These avian IncRNAs share similar characteristics with lncRNAs in mammals, such as shorter transcript length, lower exon number, lower average expression level and less sequence conservation than mRNAs. However, the proportion of lncRNAs overlapping with transposable elements in birds is much lower than that in mammals. We predicted the functions of IncRNAs based on the enriched functions of co-expressed protein-coding genes. Clusters of lncRNAs associated with natal down development were identified. The sequences and expression levels of candidate lncRNAs that shared conserved sequences among birds were validated by qPCR in both zebra finch and chicken. Finally, we identified three highly conserved lncRNAs that may be associated with natal down development.ConclusionsOur study provides the first systematical identification of avian lncRNAs using ssRNA-seq analysis and offers a resource of embryonically expressed lncRNAs in zebra finch. We also predicted the biological function of identified lncRNAs.

Contribution of Drosophila TRPA1 to Metabolism

Transient receptor potential (TRP) cation channels are highly conserved in humans and insects. Some of these channels are expressed in internal organs and their functions remain incompletely understood. By direct knock-in of the GAL4 gene into the trpA1 locus in Drosophila, we identified the expression of this gene in the subesophageal ganglion (SOGs) region. In addition, the neurites present in the dorsal posterior region as well as the drosophila insulin-like peptide 2 (dILP2)-positive neurons send signals to the SOGs. The signal is sent to the crop, which is an enlarged organ of the esophagus and functions as a storage place for food in the digestive system. To systematically investigate the role of TRPA1 in metabolism, we applied non-targeted metabolite profiling analysis together with gas-chromatography/time-of-flight mass spectrometry, with an aim to identify a wide range of primary metabolites. We effectively captured distinctive metabolomic phenotypes and identified specific metabolic dysregulation triggered by TRPA1 mutation based on reconstructed metabolic network analysis. Primarily, the network analysis pinpointed the simultaneous down-regulation of intermediates in the methionine salvation pathway, in contrast to the synchronized up-regulation of a range of free fatty acids. The gene dosage-dependent dynamics of metabolite levels among wild-type, hetero- and homozygous mutants, and their coordinated metabolic modulation under multiple gene settings across five different genotypes confirmed the direct linkages of TRPA1 to metabolism.

Self-regulated left-right asymmetric expression of Pitx2c in the developing mouse limb

The transcription factor Pitx2c is expressed in primordial visceral organs in a left-right (L-R) asymmetric manner and executes situs-specific morphogenesis. Here we show that Pitx2c is also L-R asymmetrically expressed in the developing mouse limb. Human PITX2c exhibits the same transcriptional activity in the mouse limb. The asymmetric expression of Pitx2c in the limb also exhibits dorsal-ventral and anterior-posterior polarities, being confined to the posterior-dorsal region of the left limb. Left-sided Pitx2c expression in the limb is regulated by Nodal signaling through a Nodal-responsive enhancer. Pitx2c is expressed in lateral plate mesoderm (LPM)–derived cells in the left limb that contribute to various limb connective tissues. The number of Pitx2c+ cells in the left limb was found to be negatively regulated by Pitx2c itself. Although obvious defects were not apparent in the limb of mice lacking asymmetric Pitx2c expression, Pitx2c may regulate functional L-R asymmetry of the limb.

The dynamic expression of extraembryonic marker genes in the beetle Tribolium castaneum reveals the complexity of serosa and amnion formation in a short germ insect

Most insect embryos develop with two distinct extraembryonic membranes, the serosa and the amnion. In the insect beetle Tribolium the early origin of the serosa within the anterior blastoderm is well established but the origin of the amnion is still debated. It is not known whether this tissue develops from a blastodermal precursor or originates de novo later from embryonic tissue during embryogenesis.We undertook an in-depth analysis of the spatio-temporal expression pattern profile of important extraembryonic membrane marker genes with emphasis on early blastoderm development in Tribolium.The amnion marker iroquois (Tc-iro) was found co-expressed with the serosa marker zerknüllt1 (Tc-zen1) during early blastoderm formation in an anterior cap domain. This domain later resolved into two adjacent domains that likely represent the precursors of the serosa and the amnion. In addition, we found the hindsight ortholog in Tribolium (Tc-hnt) to be a serosa-specific marker. Surprisingly, decapentaplegic (Tc-dpp) expression was not seen as a symmetric cap domain but detected asymmetrically first along the DV- and later also along the AP-axis. Moreover, we found a previously undescribed domain of phosphorylated MAD (pMAD) protein in anterior ventral serosal cells.This is the first study showing that the anterior-lateral part of the amnion originates from the anterior blastoderm while the precursor of the dorsal amnion develops later de novo from a dorsal-posterior region within the differentiated blastoderm.

E-ray를 조사한 쥐의 피부에서 증식된 keratinocyte에 의한 TGF-β1 발현

우리는 방사선피부염 동물 모델을 확립하여, 이차 면역 기관에서의 면역 세포 비율 변화를 관찰하였다. 또한, 방사선 조사에 의한 병소에서 transforming growth factor-<TEX>${\beta}1$</TEX> (TGF-<TEX>${\beta}1$</TEX>)과 interlukin-10 (IL-10)의 발현을 증가시킨 세포를 분석하였다. Hairless-1 (HR-1) 쥐의 posterior dorsal 부위에 6 일간 매일 10 Gy 씩 electron (E)-ray를 국부 조사하여 방사선피부염 모델을 만들었다. FACS를 이용하여 면역 세포 비율의 변화를 분석한 결과 비장과 림프절에 존재하는 항원제시세포와 T 세포 및 B 세포들의 비율이 E-irradiation에 의해 영향을 받았다. 피부에서 세포 특이적인 마커와 사이토카인들의 발현 양상은 면역형광염색법으로 확인하였다. 방사선 조사 후, TGF-<TEX>${\beta}1$</TEX>과 interlukin-17 (IL-17)은 regulatory T 세포(Treg)보다 keratin-14 (K-14)를 발현하는 진피의 끝부분에서 높게 발현되었다. Interlukin-10 (IL-10)는 Treg 뿐만 아니라 T helper 17 (Th17) 세포, dendritic 세포, macrophage 중 어느 것과도 같은 위치에서 검출되지 않았다. 우리의 데이터는 방사선피부염 동물 모델의 병소 안에서, TGF-<TEX>${\beta}1$</TEX>이 증식된 keratinocyte에 과발현된다는 것을 나타낸다. In this study, we established a radiodermatitis animal model and investigated the change in immune cell proportions in the secondary lymphoid organs. The cells responsible for the increased transforming growth factor-<TEX>${\beta}1$</TEX> (TGF-<TEX>${\beta}1$</TEX>) and interleukin-10 (IL-10) production in the lesions following irradiation were also investigated. The radiodermatitis model was constructed by locally exposing the posterior dorsal region of hairless-1 (HR-1) mice to 10 Gy electron (E)-ray/day for six consecutive days. The change in immune cell proportions was analyzed by FACS. Immunohistochemistry was carried out to detect the expression of cytokines and cell-specific markers in the skin. The proportions of antigen-presenting cells, T cells, and B cells in the lymph nodes and spleen were affected by E-irradiation. After irradiation, TGF-<TEX>${\beta}1$</TEX> and IL-17 were co-localized in the papillary region of the dermis with keratin-14 (K-14)-positive cells rather than with regulatory T cells (Treg). IL-10 was not co-stained with Treg, T helper 17 (Th17) cells, dendritic cells, or macrophages. Our data indicate that TGF-<TEX>${\beta}1$</TEX> is over-expressed mainly by proliferated keratinocytes in the lesions of a radiodermatitis animal model.

Gonadal Organization and Gametogenesis inMusculium argentinum(Veneroida: Sphaeriidae) from a Population in Southern Chile

The gonadal organization and cytological characteristics of gametogenesis in a population of the freshwater clam Musculium argentinum (d'Orbigny, 1835) are described. Sections of the rather small gonad demonstrate the existence of hermaphroditic specimens, and is composed of hermaphrodite follicles among the intestine coils in the posterior dorsal region of the body. Follicles contain male and female germ cells at different stages of maturation, which can be recognized by their shape, size, and nuclear features. Male germ cells are organized in cysts, and spermatocytes do carry out meiosis. Within follicles, male and female germ cells occupy different regions. Gonad activity throughout the year is coincident with the life cycle pattern of the M. argentinum population studied previously.

Outcome and view of the player modulate motor area activity during observation of a competitive game

In a previous study, we demonstrated that the mirror neuron system is involved in watching competitive games performed by multiple players [Shimada, S., & Abe, R. (2009). Modulation of the motor area activity during observation of a competitive game. NeuroReport, 20, 979–983]. In the present study, we investigated whether mirror neuron system activity was modulated by the outcome of a competitive game as well as by the spatial relationship between the player and the observer. We measured the activity of motor areas using near-infrared spectroscopy when a subject watched a two-player competitive game, rock–paper–scissors (RPS). Some parts of the motor area that was activated while performing the RPS action were also activated while observing the RPS game. Interestingly, the magnitude of this activity (during observation) was modulated by the outcome and the view of the particular player whom the subject was supporting. In the dorsal anterior region of the motor area measured, the activity was significantly greater when the supported player won rather than when he lost, regardless of the view. It was also greater when the player was presented with an incongruent view than with a congruent view, regardless of the outcome. In contrast, the dorsal posterior region of the motor area was activated only when the supported player won and was observed with a congruent view. We suggest that mirror neuron system activity during observation of a competitive game reflects the subject's internal assimilation of the actions of the observed player.

Adenomatous polyposis coli is required for early events in the normal growth and differentiation of the developing cerebral cortex

BackgroundAdenomatous polyposis coli (Apc) is a large multifunctional protein known to be important for Wnt/β-catenin signalling, cytoskeletal dynamics, and cell polarity. In the developing cerebral cortex, Apc is expressed in proliferating cells and its expression increases as cells migrate to the cortical plate. We examined the consequences of loss of Apc function for the early development of the cerebral cortex.ResultsWe used Emx1Cre to inactivate Apc specifically in proliferating cerebral cortical cells and their descendents starting from embryonic day 9.5. We observed reduction in the size of the mutant cerebral cortex, disruption to its organisation, and changes in the molecular identity of its cells. Loss of Apc leads to a decrease in the size of the proliferative pool, disrupted interkinetic nuclear migration, and increased apoptosis. β-Catenin, pericentrin, and N-cadherin proteins no longer adopt their normal high concentration at the apical surface of the cerebral cortical ventricular zone, indicating that cell polarity is disrupted. Consistent with enhanced Wnt/β-catenin signalling resulting from loss of Apc we found increased levels of TCF/LEF-dependent transcription and expression of endogenous Wnt/β-catenin target genes (Axin2 (conductin), Lef1, and c-myc) in the mutant cerebral cortex. In the Apc mutant cerebral cortex the expression of transcription factors Foxg1, Pax6, Tbr1, and Tbr2 is drastically reduced compared to normal and many cells ectopically express Pax3, Wnt1, and Wt1 (but not Wnt2b, Wnt8b, Ptc, Gli1, Mash1, Olig2, or Islet1). This indicates that loss of Apc function causes cerebral cortical cells to lose their normal identity and redirect to fates normally found in more posterior-dorsal regions of the central nervous system.ConclusionApc is required for multiple aspects of early cerebral cortical development, including the regulation of cell number, interkinetic nuclear migration, cell polarity, and cell type specification.

Specialization of phonological and semantic processing in Chinese word reading

The purpose of this study was to examine the neurocognitive network for processing visual word forms in native Chinese speakers using functional magnetic resonance imaging (fMRI). In order to compare the processing of phonological and semantic representations, we developed parallel rhyming and meaning association judgment tasks that required explicit access and manipulation of these representations. Subjects showed activation in left inferior/middle frontal gyri, bilateral medial frontal gyri, bilateral middle occipital/fusiform gyri, and bilateral cerebella for both the rhyming and meaning tasks. A direct comparison of the tasks revealed that the rhyming task showed more activation in the posterior dorsal region of the inferior/middle frontal gyrus (BA 9/44) and in the inferior parietal lobule (BA 40). The meaning task showed more activation in the anterior ventral region of the inferior/middle frontal gyrus (BA 47) and in the superior/middle temporal gyrus (BA 22,21). These findings are consistent with previous studies in English that suggest specialization of inferior frontal regions for the access and manipulation of phonological vs. semantic representations, but also suggest that this specialization extends to the middle frontal gyrus for Chinese. These findings are also consistent with the suggestion that the left middle temporal gyrus is involved in representing semantic information and the left inferior parietal lobule is involved in mapping between orthographic and phonological representations.

Altered Immune Cell Proportions in the Radiodermatitis Induced Hairless Mice-1 (HR-1)

Accidental radiation exposures or radiation therapy can cause internal and external damage including radiodermatitis. Even though radiodermatitis is one of the dose limiting factors in radiotherapy, the immunological nature of it is not yet been clearly understood. In this study, we have examined the alteration in immune cell population during the radiodermatitis process. A radiodermatitis model was established in HR-1 mice by locally exposing a posterior dorsal region to 10 Gy X-ray/day for 4 consecutive days. Collagen accumulation, redness, erythema, and dry desquamation of the skin were detected after X-irradiation. The size and total cell number of the spleen decreased immediately after X-irradiation, compared to those of the sham-irradiated mice, and recovered to the normal levels two weeks later. Reduction and recovery of the bone marrow cell population preceded a similar change of the spleen cell population. The proportion of CD4+ T cell increased, while the proportion of CD8+ T cell decreased ahead of the obvious skin damage, in both lymph node and spleen of the irradiated mice. Interestingly, the proportion of splenic monocytes/macrophages was expanded gradually at a similar kinetics with the aggravation of the radiodermatitis. The infiltration of the CD11b+ monocyte/macrophage to the X-irradiated skin also coincided with the development of radiodermatitis. These altered proportions of immune cells may play important roles in radiodermatitis.

Dual, multilayered somatosensory maps formed by antennal tactile and contact chemosensory afferents in an insect brain

The antennae of most insects move actively and detect the physical and chemical composition of objects encountered by using their associated tactile sensors. Positional information is required for these sensory modalities to interpret the physical environment. Although we have a good understanding of antennal olfactory pathways, little is known about the destinations of antennal mechanosensory and contact chemosensory (gustatory) receptor neurons in the central nervous system. The cockroach Periplaneta is equipped with a pair of long, thin antennae, which are covered in bristles. The distal portions of each antenna possess about 6,500 bimodal bristles that house one tactile sensory and one to four contact chemosensory neurons. In this study, we investigated the morphologies of bimodal bristle receptor afferents by staining individual or populations of bristles. Unlike olfactory afferents, which project exclusively into the glomeruli in the ventral region of the deutocerebrum, both the presumptive mechanosensory and the contact chemosensory afferents projected into the posterior dorsal region of the deutocerebrum and the anterior region of the subesophageal ganglion. Each afferent showed multilayered segmentation and spatial occupation reflecting its three-dimensional position in the periphery. Presumptive contact chemosensory afferents, characterized by their thin axons and unique branching pattern, occupied more medioventral positions compared with the presumptive tactile afferents. Furthermore, projection fields of presumptive contact chemosensory afferents from single sensilla tended to be segregated from each other. These observations suggest that touch and taste positional information from the antenna is precisely represented in primary centers in a modality-specific manner.

Early development of the pituitary gland in Acipenser naccarii (Chondrostei, Acipenseriformes): an immunocytochemical study.

The distribution and appearance of secretory cells in the pituitary gland were investigated for the first time in a chondrostean species, Acipenser naccarii, from embryos to juveniles, by immunohistochemistry with mammalian and teleost hormone antisera. On 5.5 day post-fertilization (2.5 days pre-hatching), the pituitary of embryos appears as an oval cell mass with a narrow central cavity (hypophysial cleft), close to the ventral border of diencephalon under the third ventricle. At that time no neurohypophysis is observed, the adenohypophysis is not yet structurally divided into pars intermedia (PI) and pars distalis (PD) and only immunoreactive growth hormone cells are detectable. Seven days post-fertilization (1 day pre-hatching) the immunoreactive thyrotropic cells appear in the ventral region and the immunoreactive adrenocorticotropic cells in the posterior dorsal one. At hatching, some immunoreactive melanotropic (ir-MSH) cells are visible in the posterior dorsal region and some immunoreactive prolactin cells in the anterior one. Eight days later the immunoreactive somatolactin cells appear along the posterior dorsal border and the immunoreactive gonadotropic I (ir-GtH I) cells in the ventral region. Here, a few ir-GtH II cells finally appear in 76-86 day old juveniles. The gland elongates after hatching and in 8-day-old larvae two adenohypophysial regions are identified: a posterior (the presumptive PI) and an anterior one (the presumptive PD). In 156-166-day-old juveniles three regions (rostral and proximal pars distalis and pars intermedia) appear and a high number of ir-MSH cells are visible in the rostral region. The first protrusion of neurohypophysis into adenohypophysis is observed in 76-86-day-old juveniles and increases with age, branching into PI. The rostro-caudal distribution of the immunoreactive cells follows the spatial expression of the corresponding hormone gene families observed in zebra fish, suggesting similar differentiating mechanisms in teleosts and chondrosteans.