Biology subjects

Torres, M. V.

Publications and source records attributed to Torres, M. V..

8 recordsLinked to original sources

bioRxiv2026

Beyond Terrestrial Carnivores: Olfactory Bulb Anatomy in a Semi-Aquatic Mammal

The organization of the olfactory systems remains poorly understood in mustelids, particularly in lutrines adapted to semiaquatic environments. This study provides the first detailed anatomical, histological, lectin-histochemical, and immunohistochemical characterization of the main (MOB) and accessory (AOB) olfactory bulbs of the Asian small-clawed otter (Aonyx cinereus). Serial transverse and sagittal sections were examined using Nissl and Tolivia staining, a panel of lectins, and neuronal and olfactory immunohistochemical markers. Macroscopically, the olfactory bulbs were prominent and elongated, although no distinct AOB could be identified. Histologically, the MOB displayed a well-developed laminar organization, abundant mitral and tufted cells, and a clearly defined lateral olfactory tract. By contrast, the AOB was small, located dorsocaudally within the olfactory peduncle, and lacked the canonical lamination observed in many other mammals. Its identification was supported by the selective binding of Ulex europaeus agglutinin and strong Gi2 immunoreactivity in glomerular-like structures, whereas Go labeling was weak. LEA and STA labeled the superficial layers of both bulbs, while VVA and SBA recognized only scattered MOB glomeruli. Neuronal markers, including NCAM, NSE, NeuN, PGP 9.5, and {beta}-tubulin III, confirmed the neuronal nature of the AOB, while calretinin strongly labeled its glomerular structures and projection neurons. These findings reveal a marked contrast between a highly developed MOB and a small, poorly laminated but neurochemically differentiated AOB. This organization indicates that the vomeronasal pathway is retained in A. cinereus, although in a structurally reduced form, and provides a comparative basis for investigating chemosensory evolution in semiaquatic carnivorans.

neuroscience↗

bioRxiv2024

Neuroanatomy of the Accessory Olfactory Bulb in the Fossorial Water Vole

The accessory olfactory bulb (AOB) plays a key role in processing chemical signals crucial for species-specific social and reproductive behaviors. While extensive research has focused on the vomeronasal system of laboratory rodents, less is known about wild species, particularly those that rely heavily on chemical communication. This study aims to characterize the morphological and neurochemical organization of the AOB in the fossorial water vole (Arvicola scherman), a subterranean rodent species from the family Cricetidae. We have employed histological techniques, including Nissl and hematoxylin staining, as well as immunohistochemical and lectin-histochemical markers, to assess the AOB structure. Our findings reveal that the AOB of the water vole exhibits a distinct laminar organization with prominent mitral cells in the mitral-plexiform layer, as well as dense labeling of periglomerular and short-axon cells in the glomerular layer. Lectin histochemistry further confirmed zonation patterns analogous to those seen in other rodent species. Immunohistochemical analysis demonstrated significant expression of PGP 9.5, suggesting its involvement in maintaining neuronal activity within the AOB. In contrast, the absence of SMI-32 labeling in the AOB, compared to its strong expression in the main olfactory bulb, highlights functional distinctions between these two olfactory subsystems. These structural and neurochemical characteristics suggest that the AOB of the fossorial water vole is adapted for enhanced processing of chemosensory signals, which may play a pivotal role in its subterranean lifestyle. Our results provide a foundation for future studies exploring the functional implications of these adaptations, including potential improvements in the integrated management of these vole populations.

neuroscience↗

bioRxiv2024

Characterization of Eye and Adnexal Tissues in Dogs and Wolves: A Histological and Lectin-Histochemical Approach

This study explores the ocular anatomy and glandular components of domestic dogs compared to their ancestor, the wolf, with the aim of identifying evolutionary changes due to domestication and their implications for ocular pathologies. Utilizing histological and histochemical techniques, including hematoxylin-eosin, PAS, Alcian Blue, and lectins, this research conducts a detailed analysis of the canine and wolf ocular systems, particularly focusing on the eyelids, tarsal glands, and conjunctival tissues. Results indicate significant histological differences between the two species, particularly in the thickness and secretion levels of the conjunctival epithelia and the structure of the tarsal glands. Dogs exhibit a thicker epithelium with greater PAS and Alcian Blue positive secretion, suggesting enhanced ocular protection and lubrication adapted to domestic environments. Conversely, wolves display more concentrated glandular secretions and a predominance of acidic mucopolysaccharides, aligning with their adaptation to natural habitats. This study also highlights the translational value of dogs as models for human ocular diseases, given their anatomical and physiological similarities with humans. Such comparisons are essential as they provide insights that can lead to advancements in medical research and clinical applications, especially in the development of treatments for ocular surface disorders.

neuroscience↗

bioRxiv2024

The Incisive Duct as a Pathway for Early Vomeronasal Communication in Neonatal Dogs

The detection of chemical signals by the vomeronasal organ (VNO) is critical for communication among mammals from an early age, influencing behaviors such as suckling and recognition of the mother and conspecifics. Located in a concealed position at the base of the nasal cavity, the VNO features a duct covered with a sensory epithelium rich in neuroreceptors. A critical aspect of VNO functionality is the efficient access of stimuli from the nasal and oral cavities to the receptors. In adult dogs, it has been demonstrated through in vivo magnetic resonance imaging and anatomically postmortem how the VNO duct (VD) communicates to the environment through the incisive duct (ID). However, in newborn puppies, the existence of functional communication between the ID and the VD has not been confirmed to date, raising doubts about the potential physiological obliteration of the ID due to its small size and the degree of immaturity of the puppies at birth. Determining this aspect is necessary to evaluate the role played by chemical communication in this critical phase for the survival and socialization of puppies. This study employs serial histological staining techniques to examine the presence and functionality of the incisive duct in neonatal dogs. The serial histological sections have confirmed both the existence of functional communication between both the vomeronasal and incisive ducts in perinatal puppies, and the dual functional communication of the incisive duct with the oral and nasal cavities. The ID shows an uninterrupted lumen along its path and is associated with a sophisticated cartilaginous complex that prevents its collapse, as well as erectile tissue rich in blood vessels and connective tissue that acts as a cushion, facilitating its action under pressure induced by sampling behaviors such as tonguing. This investigation demonstrates the communicative capabilities of the VNO during the perinatal stage in dogs.

neuroscience↗

bioRxiv2023

The Histopathology of Cephenemyia stimulator-Induced Nasopharyngeal Myiasis in Roe-Deers (Capreolus capreolus)

Nasopharyngeal myiasis in European roe deer (Capreolus capreolus) is a pathological condition caused by the larval stages of Cephenemyia stimulator, a fly from the Oestridae family. These larvae reside in the hosts upper respiratory tract for months, inducing significant tissue damage and clinical symptoms. The lifecycle of Cephenemyia stimulator is complex, involving three larval stages before maturation into adult flies, with each stage contributing to the progressive pathology observed in the host. Despite their prevalence, the histopathological effects of these larvae in the nasopharyngeal and nasal cavities have been understudied. Our study fills this knowledge gap by providing a detailed histopathological analysis of the affected tissues, using various staining techniques to reveal the extent and nature of the damage caused by these parasitic larvae. This histopathological examination reveals significant alterations within the nasopharyngeal mucosa and nasal cavity, including erythematous changes, mucosal metaplasia, fibrosis, and tissue necrosis. Parasitic cysts and eosinophilic infiltration further characterize the infestations impact, compromising not only the mucosal integrity but also potentially the olfactory function of the affected animals. This research is crucial for understanding the impact of myiasis on the health of roe deer populations and could have significant implications for wildlife management and conservation.

zoology↗

bioRxiv2023

Do Fossorial Water Voles have a Functional Vomeronasal Organ? A Histological and Immunohistochemical Study

The fossorial water vole, Arvicola scherman, is a herbivorous rodent that cause significant agricultural damages. The application of cairomones and alarm pheromones emerges as a promising sustainable method to improve its integrated management. These chemical signals would induce stress responses that could interfere with the species regular reproductive cycles and induce aversive reactions, steering them away from farmlands and meadows. However, there is a paucity of information regarding the water vole vomeronasal system, both in its morphological foundations and its functionality, making it imperative to understand the same for the application of chemical communication in pest control. This study fills the existing gaps in knowledge through a morphological and immunohistochemical analysis of the fossorial water vole vomeronasal organ. The study is primarily microscopic, employing two approaches: histological, using serial sections stained with various dyes (Hematoxylin-Eosin, PAS, Alcian Blue, Nissl), and immunohistochemical, applying various markers that provide morphofunctional and structural information. These procedures have confirmed the presence of a functional vomeronasal system in fossorial water voles, characterized by a high degree of differentiation and a significant expression of cellular markers indicative of active chemical communication in this species.

neuroscience↗

bioRxiv2023

Exploring the vomeronasal organ in an endangered antelope species

The dama gazelle is a threatened and scarcely studied species of northern Africa. Human pressure has depleted the population of dama gazelles from tens of thousands to a few hundred individuals. Since 1970, after deriving from a founder population of the last 17 surviving individuals in the Western Sahara, it has been reproduced naturally in captivity. Although certain aspects of the reproductive biology of the dama gazelle have been established in preparation for the future implementation of assisted reproductive technology there is a lack of information regarding the role of semiochemical-mediated communication in the sexual behavior of the dama gazelle. This is partially due to the lack of a neuroanatomical and morphofunctional characterization of the dama gazelle vomeronasal organ (VNO); the sensory organ responsible for the processing of pheromones. This study aims to determine the presence in the dama gazelle of a VNO fully equipped to carry out its neurosensory function and to contribute to the understanding of the interspecific variability of the VNO of ruminants. Employing histological, lectin-histochemical and immunohistochemical techniques we have performed a detailed morphofunctional evaluation of the dama gazelle VNO along its entire longitudinal axis. The findings suggest that studies of the VNO should take a similar approach, as there are significant structural and neurochemical transformations that the organ exhibits as a whole. This study contributes to the understanding of the VNO in dama gazelles and provides a basis for future studies on semiochemical-mediated communication and reproductive management of this species.

neuroscience↗

bioRxiv2022

Consumer-driven nutrient recycling of freshwater decapods: linking ecological theories and application in integrated multi-trophic aquaculture

AbstractThe Metabolic Theory of Ecology (MET) and the Ecological Stoichiometry Theory (EST) are central and complementary in the consumer-driven recycling conceptual basis. The comprehension of physiological processes of organisms at different levels of organizations is essential to explore and predict nutrient recycling behavior in different scenarios, and to design integrated productive systems that efficiently use the nutrient inputs through an adjusted mass balance. We fed with fish-feed three species of decapods from different families and with aquacultural potential to explore the animal-mediated nutrient dynamic and its applicability in productive systems. We tested whether physiological (body mass, body elemental content), ecological (diet), taxonomic and experimental (time of incubation) variables predicts N and P excretion rates and ratios across and within taxa. We also analysed body mass and body elemental content independently as predictors of N and P excretion of decapods across, among and within taxa. Finally, we verified if body content scales allometrically across and within taxa and if differed among taxa. Body mass and taxonomic identity predicted nutrient excretion rates both across and within taxa. When physiological variables were analysed independently, body size best predicted nutrient mineralization in both scales of analyses. Regarding body elemental content, only body P content scaled negatively with body mass across taxa. Results showed higher N-requirements and lower C:N of prawns than anomurans and crabs. The role of crustaceans as nutrient recyclers depends mainly on the species and body mass, and should be considered to select complementary species that efficiently use feed resources. Prawns need more protein in their feed and might be integrated with fish of higher N-requirements, while crabs and anomurans, with fish of lower N-requirements. Our study contributed to the background of MTE and EST through empirical data obtained from decapods and provided useful information to achieve more efficient aquaculture integration systems.

ecology↗