Dorsal Projection Research Articles

A new crossognathiform fish (Teleostei: †Crossognathiformes) from San José de Gracia quarry reveals a great diversity in the Cretaceous outcrops of Mexico

We describe a new species, †Buapichthys gracilis gen. et sp. nov., based on two specimens from the Turonian deposits of the San José de Gracia quarry, Molcaxac, Puebla, central Mexico. Osteological features show this new species belongs to the order †Crossognathiformes, nesting within the suborder †Pachyrhizodontoidae. The combination of features, such as a slender body, the head with cephalic spines, three hypertrophied postcleithra, the pelvic fin posterior to the dorsal fin, the first and last dorsal pterygiophores modified into scutes, and the dorsal fin bony projections shows that †Buapichthys gracilis gen. et sp. nov. is different from other crossognathiform. This new taxon represents an increase in the group's diversity, constituting the seventh species of the order †Crossognathiformes reported in Mexico. Evaluating the crossognathiform biodiversity over time indicates that the great crossognathiform diversification occurred during the Albian until the Turonian. The Mexican fossil record significantly contributes to this diversity, with about 18% of the species recognized for this period.

‘Mini DC-F’ in rhinoplasty: Diced cartilage and fascia grafts with the temporalis fascia dissected along its width – A technical note

In rhinoplasty, diced cartilage with fascia (DC-F) is a commonly used technique to enhance dorsal projection and achieve a smooth dorsum. We have developed a modified technique by dissecting the thickness of the fascia along its width, called “Mini DC-F”. This method allows for effective camouflaging of dorsal irregularities and provides a slight increase in dorsal height. This simplified and less invasive technique not only reduces operative time but also enhances the surgeon's ability to achieve a refined aesthetic result. This technique offers an intermediate option in the surgical arsenal, bridging the gap between pure camouflaging methods and those aimed at significant dorsal augmentation.

Retrograde optimized AAV tracer fails to transduce dorsal raphe nucleus projections to the basolateral amygdala

Key in aversive emotional states are serotonergic (5-HT) projections to the basolateral amygdala (BLA) originating from the dorsal raphe nucleus (DRN). Despite being critical in aversive states, the precise anatomical location of 5-HT DRN neurons that project to the BLA is not well delineated. Vital in recent advancements in neuroscience are neurotropic adeno-associated viral (AAV) vectors, which allow for long-term expression of transgenes. However, a recent study using retrograde transport optimized AAV (rAAV2-retro) tracers has shown that transfection of axon terminals and subsequent retrograde transport may not be as ubiquitous as traditional non-transgenic tracer techniques. In this study, we wanted to not only map the precise location of neurons within the DRN that project to the BLA but also test the extent to which rAAV2-retro vectors were useful tools to study these projection neurons. In C57 mice, we iontophoretically deposited (+3-μA positive current at 7s intervals for 10 min, n=3 mice) or pressure nanoinjected (100 nl, n=3 mice) rAAV2-retro expressing the fluorescent reporter GFP (rAAV2-retro-CAG-GFP) into the BLA. After allowing two weeks for GFP expression, coronal sections were prepared from perfusion-fixated tissue and GFP expression was assessed in the DRN as well as the medial entorhinal cortex (mEC), a well validated input to the BLA. We found that iontophoretic deposition failed to robustly label the DRN and mEC. In contrast, while pressure nanoinjection failed to label many DRN neurons, the mEC was robustly labeled. These results may suggest a lack of DRN axon terminals within the viral injection sites or a failure of AAV retrograde tracer transduction in DRN projections to the BLA. Future studies comparing traditional retrograde tracer techniques to our results are warranted. In sum, these results caution the use of rAAV2-retro vectors to study DRN inputs to the BLA. MH093320 (LCD & GMT). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The dorsal plate is a critical feature in the reassessment of the rotiferan genus Ptygura (Monogononta; Gnesiotrocha; Flosculariidae)

All species of Flosculariidae (Rotifera; Monogononta; Gnesiotrocha; Flosculariaceae) possess a flexible integument; they are termed illoricate. But species of four genera (Beauchampia, Floscularia, Limnias, and Ptygura) possess a distinctive hardened region on the dorsal side of their anterior end, which unfortunately has received little attention beyond the species level. In our work we study the ultrastructure of these hardened regions. In Beauchampia, Limnias, and some species of Ptygura the hardened zone takes the form of a dorsal plate (hereafter DP) with or without additional protruding processes. The DP has the shape of a ~50 µm diameter disc enfolding the anterior dorsal region of the animal, with a perimetral inward fold, smooth surface, and pores. The DP of Limnias ceratophylli shows three main ultrastructural differences from the rest of the body: (1) type of glycocalyx, (2) absence of small mounds on its surface, and (3) presence of broad cisternae at the base of the pores. In Floscularia and some Ptygura the hardened structures are reduced to a pair of dorsal projections protecting the dorsal antenna: i.e., lacking a full DP. These structures deserve attention because their adaptive importance has not been studied. Here we augment those observations with other characters: i.e., presence/absence of a birefringent body in late-stage embryos and morphology of their trophi and corona. Our goal was to provide information to help develop better taxonomy, as well as advance our understanding of the evolution of sessile taxa in general and of the potentially polyphyletic Ptygura genus in particular.

Five new species of Terebellides (Annelida, Polychaeta, Trichobranchidae) from Papua New Guinea (Bismarck and Solomon seas)

Five new species of Terebellides are described from coastal and deep waters of Papua New Guinea, using both morphology and molecular tools (for four species). Terebellides elenae n. sp. is characterized by the absence of both a glandular lateral region on TC3 and papillae on margins of the branchial lamellae and by the presence of partially fused branchial lobes with conspicuous fifth lobe and dorsal rounded projections until TC6. Terebellides fauchaldi n. sp. has a very large glandular lateral region on the third thoracic chaetiger (TC3), a fifth branchial lobe and partially fused branchial lobes, and conspicuous dorsal rounded projections on TC2–6. Terebellides madeep n. sp. is characterized by a thin glandular region on TC3 and by four free branchial lobes. Terebellides oculata n. sp. is one of the only two species in the world to have eyespots. Finally, T. papillosa n. sp. has geniculate chaetae on TC6 and TC7 and bears a large number of papillae. A majority-rule consensus tree using the 16S gene and an identification key for all Terebellides species described from the Central Indo-Pacific region are provided.

Kinrentius Wei, Dietrich & Webb, 2010 (Hemiptera: Cicadellidae: Deltocephalinae): description of two new species and taxonomic key to the genus.

Two new species of the South American genus Kinrentius are described and illustrated. Kinrentius catuaba sp. nov. from Brazil (Acre, Amazonas and Rondnia states) can be distinguished by the male pygofer with multidentate anteroventral and posteroventral processes with short dentiform processes between them and aedeagus with dorsal projection forming a distinct process and apex with paired apical processes, each subrectangular, with apical margin irregularly serrated in caudal view. Kinrentius peruvianus sp. nov. from Peru (Cusco and Madre de Dios departments) has short male pygofer posteroventral processes and aedeagus more robust and parallel sided in dorsal view, with paired apical processes, each subquadrate, with apical portion weekly sclerotized, and apical margin approximately straight and slightly serrate in caudal view. A taxonomic key to males and a distribution map of all four species of the genus are provided.

Use of Banked Fibula for Improved Nasal Reconstruction Following Free Fibula Midface Reconstruction.

Anterior maxillary deficiency caused by trauma or oncologic resection presents a complex reconstructive challenge. The authors present a technique for 2-stage midface reconstruction utilizing a vascularized free fibula flap for maxillary reconstruction, followed by nasal reconstruction at a second stage utilizing a banked fibula graft. This case series utilizes a 2-stage technique for midface reconstruction. In the first stage, a fibula-free flap was used to reconstruct the maxilla with the excess banked in the abdomen. In the second stage, this bone graft was used to restore the nasal dorsum. Two patients were included in this series. Patient 1 was a 28-year-old man who presented after a remote gunshot wound to his face, resulting in complete loss of his anterior maxilla and nasal support with midface collapse. Patient 2 was a 65-year-old man who presented with squamous cell carcinoma of the hard palate with extension into the maxilla and nasal septum. In both cases, the flaps healed without complication, providing midface restoration. Placement of the banked fibula graft in a second stage resulted in restoration of dorsal nasal projection. The authors describe the use of "spare" fibula parts for nasal reconstruction after loss of the maxilla and cartilaginous septum. The use of the fibula bone as a graft to restore the nasal dorsum in a delayed manner allows for a better assessment of the esthetic needs after the massive swelling from the initial surgery has abated. Further, this approach eliminates the need for a second donor site for nasal reconstruction.

The imaginal morphology of the species Kangella brocha (Kang and Yang, 1995) from southern China (Ephemeroptera: Ephemerellidae)

Kangella brocha (Kang & Yang, 1995), a mayfly species known on nymphs only, has been previously placed in three different genera. Here, their first-found adults and additional nymphs from southern China reveal some new characteristics. Apart from its elongated mouthparts, extended outer incisors, widened prothorax, and shortened caudal filaments in the nymph stage, the adult exhibits a robust thorax, straight forceps, and large penes with dorsal projections. These distinct features, observed in both immature and alate stages, provide compelling evidence that this species deserves an independent genus. Therefore, the genus Kangella Sartori, 2004 is reinstated, and this species is reclassified under it. Functionally, the outstanding outer incisor likely serves purposes such as digging or capturing prey. Our finding not only narrows the distribution gap between two populations of this species but also enriches the diversity of ephemerellids in terms of ecological adaptations.

The pelvic girdle in extant gonorynchiformes (Teleostei: Otomorpha)

Otophysi is one of the most important fish taxa of the world, as they make up for roughly 28% of all fish species and about two-thirds of all freshwater species worldwide. To understand their success and evolutionary history their sister-group, the Gonorynchiformes, take a key-position, e.g., for reconstructing morphological conditions in the latest common ancestors. Gonorynchiformes comprising only 40 species and have been often studied for that reason. Their pelvic girdle, however, got only little attention so far. Therefore, we studied this structure in extant gonorynchiforms and described the ontogeny in Kneria stappersii. In gonorynchiforms: (1) their basipterygium is principally flat (without dorsal or ventral projections) and placed in horizontal position, (2) has a ‘simple’ shape, i.e., it has only a single anterior process with small cartilaginous tips and becomes wider in its posterior part with a medial portion connecting to the basipterygium of the other side; (3) three radials and a pelvic splint are present, and (4) a prominent posterior process is missing. Although, the morphological situation is a lot similar as seen in clupeiforms and alepocephaliforms. Therefore, these characters have likely been present in the stem of Otomorpha, Ostariophysi, and Otophysi, but within the latter taxon eventually, a higher diversity of pelvic girdle morphology arose during evolution.

Orientatractis bowseri n. sp. (Nematoda: Cosmocercoidea: Atractidae) parasite of Peltocephalus dumerilianus (Schweigger) (Testudines: Podocnemididae) from the Brazilian Amazon.

Peltocephalus dumerilianus (Schweigger) is a diurnal freshwater turtle widely distributed in the Orinoco and Amazon River basins in Brazil, Colombia, Peru, Ecuador, Venezuela, and French Guiana. During a helminthological survey of freshwater turtles from the Brazilian Amazon, numerous nematodes with characteristics of the genus Orientatractis Petter, 1966 were recovered from the stomach of Peltocephalus dumerilianus. These nematodes were different from all congeneric species, and we describe herein. Orientatractis bowseri n. sp. differs from all known species of the genus by having dorsal cuticular projections on the posterior region of the females, distribution of caudal papillae and by having papilla-like ornamentations on the cuticle distributed from the mid-esophagus to the mid portion of the body. This study represents the fourth specie of the genus Orientatractis reported in Brazil, the seventh species of Orientatractis in the Neotropical region, and the third found infecting freshwater turtles in Brazil.

Serial block-face scanning electron microscopy of the tail tip of post-metamorphic amphioxus finds novel myomeres with odd shapes and unusually prominent sclerocoels.

Serial block-face scanning electron microscopyof the tail tip of post-metamorphic amphioxus (Branchiostoma floridae) revealed some terminal myomeres never been seen before with other techniques. The morphology of these myomeres differed markedly from the chevron shapes of their more anterior counterparts. Histologically, these odd-shaped myomeres ranged from empty vesicles bordered by undifferentiated cells to ventral sacs composed of well-developed myotome, dermatome, and sclerotome. Strikingly, several of these ventral sacs gave rise to a nipple-like dorsal projection composed either entirely of sclerotome or a mixture of sclerotome and myotome. Considered as a whole, from posterior to anterior, these odd-shaped posterior myomeres suggested that their more substantial ventral part may represent the ventral limb of a chevron, while the delicate projection represents a nascent dorsal limb. This scenario contrasts with formation of chevron-shaped myomeres along most of the antero-posterior axis. Although typical chevron formation in amphioxus is surprisingly poorly studied, it seems to be attained by a dorso-ventral extension of the myomere accompanied by the assumption of a V-shape; this is similar to what happens (at least superficially) in developing fishes. Another unusual feature of the odd-shaped posterior myomeres of amphioxus is their especially distended sclerocoels. One possible function for these might be to protect the posterior end of the central nervous system from trauma when the animals burrow into the substratum.

Patterns in antipredator armature reduction and maintenance in isolated spring populations of an amphipod crustacean.

Organisms colonizing new habitats can undergo adaptive change due to novel selective landscapes encountered in the new environment. Examples in nature where the development of the same traits has repeatedly occurred on multiple independent occasions upon colonizing a novel habitat represent instances of parallel evolution. Here we test whether the colonization of spring habitat by the principally lacustrine amphipod crustacean Pallaseopsis quadrispinosa has resulted in parallel evolution in armature traits using empirical data on morphology and mitochondrial DNA and through a breeding experiment. Analysis of mtDNA CO1 sequences shows that the spring populations share no common history and have evolved in isolation from each other and from their neighbouring lake populations since deglaciation approximately 12,000 years ago and are now fixed for different haplogroups. Dorsal spines and lateral projections were absent or less developed in all spring populations than in lake populations. Variation in armature development also could be explained by predator presence as populations with fish predators exhibited more developed spines than those without fish. In a laboratory breeding experiment, hybrid Spring × Lake F1 offspring had intermediate development of armature compared to offspring of Lake × Lake and Spring × Spring matings. The results support the hypothesis that armature reduction has independently evolved on multiple occasions in P. quadrispinosa. Recent research has questioned the degree to which parallel evolution actually explains variance in traits. Taking into account the predation regime, sexual dimorphism and mineral composition of the trait, a more precise understanding of the factors influencing parallel evolution emerges.

Athripsodes saral sp. n., a new Leptoceridae (Trichoptera) from the Kurdistan Province, Iran

In this paper, we describe Athripsodes saral sp. n., a new species from the Kurdistan Province, Iran, which belongs to the A. sewangensis Species Group. The new species is morphologically most similar to Athripsodes caglari Sipahiler, 2008 from Turkey and Athripsodes sewangensis Martynov, 1925 from Armenia. However, it can be distinguished from all known species of this group by notable morphological characteristics of the male and female genitalia. In males, the dorsal projection of the coxopodite is slightly longer or equal in size to the harpago, while in females, the dorsolateral lobes of segment IX exhibit a distinct triangular shape, visible in both ventral and dorsal views. Furthermore, the new species displays distinct characteristics from its closest congeners in the shape of segment IX, prolongations of segment X, and the structure of the aedeagus in males.
 Athripsodes saral sp. n. is the third known species of the genus Athripsodes Billberg, 1820 known from Iran.

Adult-born neurons maintain hippocampal cholinergic inputs and support working memory during aging.

Adult neurogenesis is reduced during aging and impaired in disorders of stress, memory, and cognition though its normal function remains unclear. Moreover, a systems level understanding of how a small number of young hippocampal neurons could dramatically influence brain function is lacking. We examined whether adult neurogenesis sustains hippocampal connections cumulatively across the life span. Long-term suppression of neurogenesis as occurs during stress and aging resulted in an accelerated decline in hippocampal acetylcholine signaling and a slow and progressing emergence of profound working memory deficits. These deficits were accompanied by compensatory reorganization of cholinergic dentate gyrus inputs with increased cholinergic innervation to the ventral hippocampus and recruitment of ventrally projecting neurons by the dorsal projection. While increased cholinergic innervation was dysfunctional and corresponded to overall decreases in cholinergic levels and signaling, it could be recruited to correct the resulting memory dysfunction even in old animals. Our study demonstrates that hippocampal neurogenesis supports memory by maintaining the septohippocampal cholinergic circuit across the lifespan. It also provides a systems level explanation for the progressive nature of memory deterioration during normal and pathological aging and indicatesthat the brain connectome is malleable by experience.

First record of the genus Pseudaeginella Mayer, 1890 (Crustacea, Amphipoda, Caprellidae) with a new species from Korean waters.

A new species of the genus Pseudaeginella Mayer, 1890 belonging to the family Caprellidae Leach, 1814 was collected from the South Sea in Korea. Pseudaeginellacarinaspinosasp. nov. is morphologically similar to related congeners belonging to the genera Paradeutella Mayer, 1890 and Pseudaeginella, in having dorsal projections on pereonites, triarticulate mandibular palp, small or absent molar, and uniarticulate pereopods 3 and 4. However, this new species is distinguished from its congeners by the position and size of dorsal projection. This is the first record of Pseudaeginella from the Northwest Pacific region, including Korea, and a key to species of the genus Pseudaeginella is also provided.

Common Dorsal Flaws Following Preservation Rhinoplasty: A Systemic Analysis.

There has recently been a resurgence of interest in preservation rhinoplasty (PR) for dorsal hump elimination or dorsal projection reduction. However, no studies have scrutinized aesthetic outcomes to identify common pattern of flaws seen in published images to aid those with ardent enthusiasm for this technique to become aware of the frequency of these flaws and find ways to reduce imperfections. A systematic literature review was performed using search terms ("preservation" OR "let down", "push down") AND "rhinoplasty" on PubMed, Cochrane, SCOPUS, and EMBASE databases for studies between January 2000 and December 2022. Patient images from these studies were analyzed by three reviewers (MWW, IAC, and BG) for dorsal flaws. Raw interrater agreement percentage and Krippendorff's alpha were calculated to determine interrater reliability. A descriptive and comparative analysis with Fisher's exact test was performed for the aggregate data. There were 59 patient images with 464 views from 24 studies included for final analysis. Optimal dorsal aesthetic lines (DAL) were noted in 12 patients (20.3%), while optimal profile was observed in 15 patients (25.4%) (p=0.66). Combined ideal front and profile view of dorsum was not observed on any patients. The most common flaws were DAL irregularities (n=45; 78.0%), dorsal deviation (n=32, 54.2%), and residual hump (n=25, 42.4%). There was excellent interrater agreement. While PR may have some advantages, it has shortcomings in outcomes, particularly dorsal irregularities, dorsal deviation, and residual humps. Awareness of these imperfections may compel those performing this procedure to modify their techniques and improve their results. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

ID: 199708 Significant Pain Relief Using an SCS System Delivering Novel Fast-Acting Sub-Perception Therapy

Sub-perception Spinal Cord Stimulation (SCS) is now a commonly used treatment approach in the treatment of chronic pain.1-3 Fast-Acting Sub-Perception Therapy (FAST) is a new SCS method that utilizes precise stimulation field location and optimal neural dosing. Computational modeling suggests that FAST-SCS activates dorsal column axons and inhibits dorsal horn projection neurons via the surround inhibition mechanism. Recently published reports suggested that FAST-SCS is capable of provide profound pain relief with rapid onset of analgesia within minutes.4 Here, we present a single-center experience with the use of FAST and other therapies in the treatment of chronic pain.

A four-year clinical and sonographic longitudinal follow-up of clubfeet treated according to Ponseti with normal references.

To follow children with a clubfoot by ultrasonography during the entire treatment period up to 4 years and compare with controls. Thirty clubfeet in 20 children treated using the Ponseti method and 29 controls were followed by repeated ultrasonography investigations from neonates to the age of 4 years. The previously established coronal medial and lateral, sagittal dorsal and posterior projections were used. Changes over time, correlations to the Diméglio score, and the course of treatment were studied. The medial malleolus-navicular distance was shorter, while the talar tangent-navicular distance and the talo-navicular angle were larger in clubfeet than in controls even after the initial correction. The healthy feet in unilateral cases did not differ significantly from the controls. The range of motion in the talo-navicular joint was approximately 20° less in clubfeet than in controls during the first four years of life. The medial malleolus-navicular distance (r = -0.58) and the talo-navicular angle (r = 0.66) at the first ultrasonography showed the highest correlation to the number of casts needed to correct the deformities. Ultrasonography can be used to evaluate the initial degree of deformities in clubfeet and to follow the progress of the treatment and growth. Ultrasonography showed a clear difference between clubfeet and controls during the first four years of life. Although it was not possible to define specific limit values as benchmarks in the treatment, dynamic ultrasonography can provide valuable support in the decision-making process when complementary treatment may be needed. III.

The hammer graft: A novel technique to provide dorsal support, tip projection, and rotation in rhinoplasty

BackgroundThere are numerous cartilaginous grafts that can be used in rhinoplasty, depending on the specific needs of the patient. These include spreader grafts, dorsal onlay, tip grafts, septal extension, and columellar struts grafts, among others. ObjectiveThe aim of this study is to demonstrate use of the hammer graft in rhinoplasty; this technique can be used to improve dorsal support, tip projection, and tip rotation using a single cartilage graft. Materials and methodsThis novel graft was applied in 18 patients who underwent rhinoplasty. In revision patients, hammer graft was harvested from costal cartilage and in primary cases from septum cartilage. They were followed in average 12 months (between 6 and 18 months). ResultThree of these patients were revision cases and 15 were primary cases. In revision patients, hammer graft was harvested from costal cartilage and in primary cases from septal cartilage. The targeted results were achieved to a large extent in all patients. All patients had satisfactory esthetic results. ConclusionThe hammer graft as a single and stable graft useful support for the dorsal part, caudal part and extension part of the septum to be used in primary and revision rhinoplasty.

C-Maf-positive spinal cord neurons are critical elements of a dorsal horn circuit for mechanical hypersensitivity in neuropathy

Corticospinal tract (CST) neurons innervate the deep spinal dorsal horn to sustain chronic neuropathic pain. The majority of neurons targeted by the CST are interneurons expressing the transcription factor c-Maf. Here, we used intersectional genetics to decipher the function of these neurons in dorsal horn sensory circuits. We find that excitatory c-Maf (c-MafEX) neurons receive sensory input mainly from myelinated fibers and target deep dorsal horn parabrachial projection neurons and superficial dorsal horn neurons, thereby connecting non-nociceptive input to nociceptive output structures. Silencing c-MafEX neurons has little effect in healthy mice but alleviates mechanical hypersensitivity in neuropathic mice. c-MafEX neurons also receive input from inhibitory c-Maf and parvalbumin neurons, and compromising inhibition by these neurons caused mechanical hypersensitivity and spontaneous aversive behaviors reminiscent of c-MafEX neuron activation. Our study identifies c-MafEX neurons as normally silent second-order nociceptors that become engaged in pathological pain signaling upon loss of inhibitory control.