874 research outputs found
Involvement of chemical perception in control of reproduction in Octopus vulgaris
No full textAmong invertebrates reproductive strategies are much more diversified than vertebrates. Recently we have found in Octopus vulgaris that olfactory sensory neurons (OSNs) express several peptides involved in reproduction and feed intake such as GnRH and NPY (Polese et al., 2015). We suggest at central level, a context-dependent modulation of olfactory epithelial activity by olfactory lobe making the octopus female more sensitive to a sex related stimulus rather than a food one during reproduction. In Octopus vulgaris mainly two lobes, subpedunculate lobe and olfactory lobe (supraoesophageal mass), and a neuroendocrine gland (the optic gland) are the neuroanatomical areas involved in the central control of reproduction. In those, several neuropeptides, NMDA receptors, an oestrogen receptor, oct-ER work in synergy to modulate optic gland activity, in turn involved in the production of a gonadotropin still unknown. The olfactory lobe plays a crucial role in mediating sexual behavior, functioning as an integrative centre in which converges chemosensory information intercepted by olfactory organ via the OSNs. At peripheral level the control of reproduction is mediated by fusiform ganglion that innervates the reproductive tracts in both male and female. Neuropeptides, sex steroid hormones, optic gland hormone and a recently discovered chemoattractant factor octo-SAP are the peripheral physiological players responsible of reproductive behavior. Despite the advanced state of knowledge about the mechanisms that regulate reproduction in Octopus vulgaris and cephalopods in general, many questions remain unanswered
MABS validation through repeated execution and data mining analysis
No full textAgent Based Modelling is the most interesting and advanced approach for simulating a complex system: in a social context, the single parts and the whole are often very hard to describe in detail. Besides, there are agent based formalisms which allow to study the emergency of social behaviour with the creation and study of models, known as artificial societies. Thanks to the ever increasing computational power, it's been possible to use such models to create software, based on intelligent agents, which aggregate behaviour is complex and difficult to predict, and can be used in open and distributed systems. Data mining is born in the last decades in order to help users in finding useful knowledge from the otherwise overwhelming amount of data available nowadays from the web and the data collected every day by companies. Data Mining techniques can therefore be the keystone to reveal non-trivial knowledge expressed by the initial assumption used to build the micro-level of the model and the structure of the society of agents that emerged from the simulation
Neuroendocrine-Immune Systems Response to Environmental Stressors in the Cephalopod Octopus vulgaris
No full textUnder a continuous changing environment, animals are challenged with stresses and stimuli which demanding adaptation at behavioral and physiological levels. The adaptation strategies are finely regulated by animal nervous, endocrine, and immune systems. Although it's been established by now the usage of integrative approach to the study the endocrine and nervous systems (neuroendocrine), yet our understanding of how they cooperate with the immune system remains far from complete. The possible role that immune system plays as a component of the network has only been recognized recently. Octopus vulgaris is an important member of cephalopods and is considered as a model species, with considerable information about the neuroendocrine and immune systems. In the current review, we anticipate to shed light on the complexity and cross talk among the three systems and how they cooperate in setting physiological response to stresses-stimuli in O. vulgaris as a target species and primary example
Molluscan Bioactive Peptides
No full textIn this chapter, we try to provide a detailed summary of the stud-
ies reporting: discovery, gene organization, distribution, receptors, and biological action of peptides in the phylum Mollusca. Peptides have been collected in families or groups according to molecular structure. In separate subsections, we group structurally differ- ent peptides sharing a common biological action. According to these criteria, the RFamide peptides, and tachykinins, have been discussed as members of one peptide family. Other peptides are presented according to their involvement in energy flow, growth, feeding behavior, osmoregulation, and reproduction. Finally, a detailed analysis of peptides involved in egg laying and sexual behavioral repertoires is also reported
Cephalopod Olfaction
No full textWithin the Phylum Mollusca, cephalopods encompass a small and complex group of exclusively marine animals that live in all the oceans of the world with the exception of the Black and Caspian seas. They are distributed from shallow waters down into the deep sea, occupying a wide range of ecological niches. They are dominant predators and themselves prey with high visual capability and well-developed vestibular, auditory, and tactile systems. Nevertheless, their perceptions are chemically facilitated, so that water-soluble and volatile odorants are the key mediators of many physiological and behavioral events.
For cephalopods as well as the other aquatic animals, chemical cues convey a remarkable amount of information critical to social interaction, habitat selection, defense, prey localization, courtship and mating, affecting not only individual behavior and population-level processes, but also community organization and ecosystem function. Cephalopods possess chemosensory systems that have anatomical similarities to the olfactory systems of land-based animals, but the molecules perceived from distance are different because their water solubility is of importance. Many insoluble molecules that are detected from distance on land must, in an aquatic system, be perceived by direct contact with the odour source. Most of the studies regarding olfaction in cephalopods have been performed considering only waterborne molecules detected by the “olfactory organs.” However cephalopods are also equipped with “gustatory systems” consisting of receptors distributed on the arm suckers in octopods, buccal lips in decapods, and tentacles in nautiluses.
To date, what is known about the olfactory organ in cephalopods comes from studies on nautiloids and coleoids (decapods and octopods). In the nautiloid’s olfactory system, there is a pair of rhinophores located below each eye and open to the environment with a tiny pore, whereas in coleoids a small pit of ciliated cells is present on either side of the head below the eyes close to the mantle edge
Context-dependent modulation of olfactory epithelial activity by the terminal nerve in axolotls (Ambystoma mexicanum)
No full textA Neuroplastic Network Underlying Behaviour and Seasonal Change in Lymnaea stagnalis: A Neuroecological Standpoint
No full textThe gastropod mollusc Lymnaea stagnalis (L.) is an advantageous model system for neureothological studies and is a suitable model for studying Neuroecology. Here we describe its well organised nervous system many of whose ganglia have been mapped, both electrophysiologically and morphologically, to characterise individual giant neurons and neuronal clusters. This has allowed us to speculate on the evolution and reorganisation of the brain in relation to torsion and detorsion and to show that many behavioural networks remain virtually intact during these processes, but reflect the evolutionary changes that the nervous system has undergone in adaptation of the animal to its environment.
We also describe the Lymnaea behavioural hierarchy in which the defensive whole body withdrawal reflex takes precedence over all other behaviours, all of which appear to be organised on a multiganglionic basis and underlain by a complex neural network in which several central pattern generators (CPGs) are embedded. The interactions of the CPGs with one another and with a number of wide-acting synaptic inputs are discussed with particular reference to the locomotor and respiratory systems of the animal. Knowledge of these cellular interactions has allowed us to demonstrate seasonal changes within the respiratory CPG (RCPG) of Lymnaea with a loss of connectivity as winter approaches and a restoration of synaptic connectivity and the behavioural programme during the spring.
With its flexible and adaptable behavioural repertoire Lymnaea is well adapted to its freshwater environment. We suggest that it will prove to be a useful and sensitive model for studying the neuroecological effects of climate change with particular respect to invasive freshwater species (IFS) such as predators, freshwater plans or microbial species
How problem solving changes affect adult neurogenesis in Octopus vulgaris
No full textOctopus vulgaris has a complex and centralized nervous system, located around oesophagus, with a hierarchical organization. It is considered the most intelligent invertebrate due to its advanced cognitive capability, as learning and memory, and complex behaviour that results in an enormous capability of problem solving. “Problem solving” is the capability to use cognitive processing to find a solution to a problematic situation. Several behavioural experiments show that octopus has this kind of skill (FINN et al., 2009). Neural plasticity and synaptic remodelling are the base of adult neurogenesis that occur in organisms that have complex and centralized nervous system, as teleosts, amphibians, reptiles, birds and mammals, and among invertebrates, decapods and insects. Recently, our group demonstrated its occurrence also in O. vulgaris brain, resulting the first demonstration across Lophotrochozoa clade.
The experimental data have been obtained by problem solving behavioural experiments and the evaluation of the Oct-Pax6 expression. Pax6 gene is known as neurogenic marker during cephalopod brain development (NAVET et al., 2017). Specimens of O. vulgaris were divided into two experimental groups: challenged and control. After the acclimatization period, the standard housing condition was altered adding jars containing food providing a cognitive challenge. During experimental days, octopuses had not feeding opportunities except to open the jars to reach the food. Control animals were not challenged and they were fed regularly without any task. At last, challenged and control octopuses were scarified as described in POLESE et al. (2014) and their brains were dissected out to be processed for RNA extraction with Trizol. cDNA obtained was used to evaluate the amount of Oct-Pax6 through a semi-quantitative PCR, using -tubulin as normalizer. PCR products were analysed on 2% agarose gel at the Bio-Rad ChemiDoc, and quantified using ImageJ.
Our data show that octopuses challenged with problem solving tasks vs. unchallenged animals result in up- regulation of Oct-Pax6 in areas of the brain previously described as sites of adult neurogenesis (BERTAPELLE et al., 2017).
In conclusion, these results support that intellectual, physical and sensory challenges increase neural plasticity and synaptic remodelling through adult neurogenesis
Evolution of Vertebrate Olfactory Subsystems
No full textAbstract: In this article, we describe the basic aspects of the structure and function of the olfactory system in the major groups of vertebrates. For each group, we discuss the behavioral significance of olfactory cues, as well as the means by which odorants are drawn across the sensory epithelium. We also describe the morphology of the receptor cell types that are present, and summarize the state of knowledge concerning the odorant receptor gene repertoire. The cell types and organization of the olfactory bulbs are described, as are the major central projections from the olfactory bulbs. In addition, the olfactory system proper and vomeronasal system are compared in taxa that possess both systems. Finally, the structure of the terminal nerve is described, and information concerning its function is summarized. Patterns of evolutionary change in each of these features are then analyzed
Enriched Environment Increases PCNA and PARP1 Levels in Octopus vulgaris Central Nervous System: First Evidence of Adult Neurogenesis in Lophotrochozoa
No full textOrganisms showing a complex and centralized nervous system, such as teleosts, amphibians, reptiles, birds and mammals, and among invertebrates, crustaceans and insects, can adjust their behavior according to the environmental challenges. Proliferation, differentiation, migration, and axonal and dendritic development of newborn neurons take place in brain areas where structural plasticity, involved in learning, memory, and sensory stimuli integration, occurs. Octopus vulgaris has a complex and centralized nervous system, located between the eyes, with a hierarchical organization. It is considered the most "intelligent" invertebrate for its advanced cognitive capabilities, as learning and memory, and its sophisticated behaviors. The experimental data obtained by immunohistochemistry and western blot assay using proliferating cell nuclear antigen and poli (ADP-ribose) polymerase 1 as marker of cell proliferation and synaptogenesis, respectively, revealed cell proliferation in areas of brain involved in learning, memory, and sensory stimuli integration. Furthermore, we showed how enriched environmental conditions affect adult neurogenesis
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