Distribution of choline acetyltransferase (ChAT) immunoreactivity in the brain of the teleost cyprinus carpio

Cholinergic systems play a role in basic cerebral functions and its dysfunction is associated with deficit in neurodegenerative disease. Mechanisms involved in human brain diseases, are often approached by using fish models, especially cyprinids, given basic similarities of the fish brain to that of mammals. In the present paper, the organization of central cholinergic systems have been described in the cyprinid Cyprinus carpio, the common carp, by using specific polyclonal antibodies against ChAT, the synthetic enzyme of acetylcholine, that is currently used as a specific marker for cholinergic neurons in all vertebrates. In this work, serial transverse sections of the brain and the spinal cord were immunostained for ChAT. Results showed that positive neurons are present in several nuclei of the forebrain, the midbrain, the hindbrain and the spinal cord. Moreover, ChAT-positive neurons were detected in the synencephalon and in the cerebellum. In addition to neuronal bodies, afferent varicose fibers were stained for ChAT in the ventral telencephalon, the preoptic area, the hypothalamus and the posterior tuberculum. No neuronal cell bodies were present in the telencephalon. The comparison of cholinergic distribution pattern in the Cyprinus carpio central nervous system has revealed similarities but also some interesting differences with other cyprinids. Our results provide additional information on the cholinergic system from a phylogenetic point of view and may add new perspectives to physiological roles of cholinergic system during evolution and the neuroanatomical basis of neurological diseases

Distribution of choline acetyltransferase (ChAT) immunoreactivity in the CNS of the common carp cyprinus carpio

Cholinergic systems play a role in basic cerebral functions and a number of human neurodegenerative disorders. Mechanisms involved in human brain diseases, including Parkinson's disease (1), are often approached by using fish models, especially cyprinids, given basic similarities of the fish brain to that of mammals. In the present paper, the organization of central cholinergic systems have been described in the cyprinid Cyprinus carpio, the common carp, by using specific polyclonal antibodies against ChAT, the synthetic enzyme of acetylcholine, that is currently used as a specific marker for cholinergic neurons in all vertebrates. In this work, serial transverse and sagittal sections of the brain and the spinal cord were immunostained for ChAT. Results showed that positive neurons are present in several nuclei. In particular, ChAT-immunoreactive (ir) neurons were found in the forebrain (preoptic region, habenula), the midbrain (optic tectum, oculomotor nucleus, rostral tegmental nucleus), the hindbrain and the spinal cord (reticular formation, nucleus isthmi, secundary gustatory nucleus, cranial nerve motor nuclei from IV to X, spinal cord motoneurons). Moreover, ChAT-ir neurons were detected in the synencephalon (nucleus of the medial longitudinal fascicle) and in the cerebellum. In addition to neuronal bodies, afferent varicose fibers were stained for ChAT in the ventral telencephalon, the preoptic area, the hypothalamus and the posterior tuberculum. No neuronal cell bodies were present in the telencephalon. The comparison of ChAT-ir distribution observed in the present study with that reported in other CNS of cyprinids (2,3) has revealed a number of similarities and also some interesting differences. Our results provide additional information on the cholinergic system from a phylogenetic point of view, suggesting that cholinergic systems of the common carp show many primitive features that have been conserved during evolution, together with characteristics that are exclusive. In addition, the present study may add new perspectives to physiological roles of cholinergic system during evolution and the neuroanatomical basis of neurological diseases

Synuclein expression in the lizard Anolis carolinensis

The synuclein (syn) family comprises three proteins: alpha-, beta- and gamma-syns. In humans, they are involved in neurodegenerative diseases such as Parkinson's disease and in tumors. Members of the syn family were sequenced in representative species of all vertebrates and the comparative analysis of amino acid sequences suggests that syns are evolutionarily conserved, but information about their expression in vertebrate lineages is still scarce and completely lacking in reptiles. In this study, the expression of genes coding for alpha-, beta- and gamma-syns was analyzed in the green lizard Anolis carolinensis by semiquantitative RT-PCR and Western blot. Results demonstrate good expression levels of the three syns in the lizard nervous system, similarly to human syns. This, together with the high identity between lizard and human syns, suggests that these proteins fulfill evolutionarily conserved functions. However, differences between lizard and humans in the expression of syn variants (two different variants of gamma-syn were detected in A. carolinensis) and differences in some amino acids in key positions for the regulation of protein conformation and affinity for lipid and metal ions also suggest that these proteins may have acquired different functional specializations in the two lineages

Localization of α-synuclein in teleost central nervous system: immunohistochemical and Western blot evidence by 3D5 monoclonal antibody in the common carp, Cyprinus carpio

Alpha synuclein (α-syn) is a 140 amino acid vertebrate-specific protein, highly expressed in the human nervous system and abnormally accumulated in Parkinson's disease and other neurodegenerative disorders, known as synucleinopathies. The common occurrence of α-syn aggregates suggested a role for α-syn in these disorders, although its biological activity remains poorly understood. Given the high degree of sequence similarity between vertebrate α-syns, we investigated this proteins in the CNS of the common carp Cyprinus carpio, with the aim of comparing its anatomical and cellular distribution with that of mammalian α-syn. The distribution of α-syn was analyzed by semiquantitative Western blot, immunohistochemistry and immunofluorescence by a novel monoclonal antibody (3D5) against a fully conserved epitope between carp and human α-syn. The distribution of 3D5 immunoreactivity was also compared with that of ChAT, TH and 5HT by double immunolabelings. Results show that α-syn-like protein of about 17 kDa is expressed to different levels in several brain regions and in the spinal cord. Immunoreactive materials were localized in neuronal perikarya and varicose fibers but not in the nucleus. Present findings indicate that α-syn-like proteins may be expressed in few subpopulations of catecholaminergic and serotoninergic neurons in the carp brain. However, evidence of cellular colocalization 3D5/TH or 3D5/5HT was rare. Differently, the same proteins appear to be co-expressed with ChAT by cholinergic neurons in several motor and reticular nuclei. These results sustain the functional conservation of the α-syn expression in cholinergic systems and suggest that α-syn modulates similar molecular pathways in phylogenetically distant vertebrates. This article is protected by copyright. All rights reserved

Feeding behaviour of larval European sea bass (Dicentrarchus labrax L.) in relation to temperature and prey density

The feeding behaviour of larval European sea bass (Dicentrarchus labrax, L.) was analysed in relation to temperature and prey density under controlled laboratory conditions with the aim to assess the ability of larval fish to change the feeding tactic as a response to environmental changes. Larvae were acclimated for 20 days at three different temperatures (19, 22 and 26°C), and their feeding behaviour was then video-recorded in experimental trials, at two prey densities, consisting of swarms of 400/l and 1440/l Artemia nauplii. Results showed that there was a significant effect of the interaction between temperature and prey density on the proportion of swimming activity that was reduced at the high temperature-high prey density combination. This suggested a switching in the larval feeding behaviour from an active to an ambush tactic, when the temperature reached 26°C and the prey density was 1440 /l Artemia nauplii. These results are consistent with the current literature on fish larval behaviour in showing that the foraging tactic can be modulated by the interaction of different abiotic and biotic factors characterising the rearing environment

The Relation between Collaborative Consumption and Subjective Well-Being: An Analysis of P2P Accommodation

The present paper investigates the relationships between Collaborative Consumption (CC) and well-being. Specifically, the study aims to understand the antecedents of subjective well-being (SWB) in peer-to-peer (P2P) accommodation services. The research adopts a mixed-method approach by integrating qualitative (focus groups) and quantitative (survey) methods with sequential logic. A conceptual model was developed and validated through structural equation modelling (SEM). The model confirms that the SWB, which has three indirect antecedents (the social, environmental and economic dimensions), was positively influenced by the attitude towards P2P accommodation services, and the relation between this construct and SWB emphasizes the originality of the study. This research contributes to the current sharing economy debate, unveiling theoretical advances on the link between collaborative services and well-being

CONSUMO CONSCIENTE, VALOR E LEALDADE EM PRODUTOS ECOLOGICAMENTE CORRETOS

RESUMO O consumo consciente vem sendo apontado como uma alternativa para a preservação econômica e social de nosso planeta. O consumo consciente pode ser caracterizado a partir de quatro dimensões: consciência ecológica, economia de recursos, reciclagem e frugalidade ou planejamento. Assim, quanto mais consciente o consumidor, maior sua percepção de valor (qualidade e benefícios percebido) com relação aos produtos ecologicamente corretos. O valor para o consumidor afeta positivamente a lealdade (lealdade verde). A relação entre as quatro dimensões do consumo consciente e o valor percebido e a relação entre valor para o cliente e a lealdade são mais fortes em situações de consumo de maior envolvimento. Tendo em vista estas relações, este estudo tem por objetivo propor um framework teórico que relaciona as dimensões do consumo consciente, o valor percebido em produtos ecologicamente corretos, a lealdade e o envolvimento, como formas de melhor  entender a estrutura do comportamento do consumidor consciente.Palavras-chave: dimensões do consumo consciente, produtos ecologicamente corretos, valor percebido, envolvimento, lealdade verd