Acts of appetite: neural circuits governing the appetitive, consummatory, and terminating phases of feeding.

The overconsumption of highly caloric and palatable foods has caused a surge in obesity rates in the past half century, thereby posing a healthcare challenge due to the array of comorbidities linked to heightened body fat accrual. Developing treatments to manage body weight requires a grasp of the neurobiological basis of appetite. In this Review, we discuss advances in neuroscience that have identified brain regions and neural circuits that coordinate distinct phases of eating: food procurement, food consumption, and meal termination. While pioneering work identified several hypothalamic nuclei to be involved in feeding, more recent studies have explored how neuronal populations beyond the hypothalamus, such as the mesolimbic pathway and nodes in the hindbrain, interconnect to modulate appetite. We also examine how long-term exposure to a calorically dense diet rewires feeding circuits and alters the response of motivational systems to food. Understanding how the nervous system regulates eating behaviour will bolster the development of medical strategies that will help individuals to maintain a healthy body weight.

The neuropeptide Pth2 modulates social behavior and anxiety in zebrafish.

Behavior is context-dependent and often modulated by an animal's internal state. In particular, different social contexts can alter anxiety levels and modulate social behavior. The vertebrate-specific neuropeptide parathyroid hormone 2 (pth2) is regulated by the presence of conspecifics in zebrafish. As its cognate receptor, the parathyroid hormone 2 receptor (pth2r), is widely expressed across the brain, we tested fish lacking the functional Pth2 peptide in several anxiety-related and social behavior paradigms. Here, we show that the propensity to react to sudden stimuli with an escape response was increased in pth2 -/- zebrafish, consistent with an elevated anxiety level. While overall social preference for conspecifics was maintained in pth2 -/- fish until the early juvenile stage, we found that both social preference and shoaling were altered later in development. The data presented suggest that the neuropeptide Pth2 modulates several conserved behaviors and may thus enable the animal to react appropriately in different social contexts.

The neuropeptide Pth2 dynamically senses others via mechanosensation.

Species that depend on membership in social groups for survival exhibit changes in neuronal gene expression and behaviour when they face restricted social interactions or isolation1-3. Here we show that, across the lifespan of zebrafish (Danio rerio), social isolation specifically decreased the level of transcription of pth2, the gene that encodes the vertebrate-specific neuropeptide Pth2. However, 30 minutes of exposure to conspecifics was sufficient to initiate a significant rescue of pth2 transcript levels in previously isolated zebrafish. Transcription of pth2 exhibited bidirectional dynamics; following the acute isolation of socially reared fish, a rapid reduction in the levels of pth2 was observed. The expression of pth2 tracked not only the presence of other fish but also the density of the group. The sensory modality that controls the expression of pth2 was neither visual nor chemosensory in origin but instead was mechanical, induced by the movements of neighbouring fish. Chemical ablation of the mechanosensitive neuromast cells within the lateral line of fish prevented the rescue of pth2 levels that was induced by the social environment. In addition, mechanical perturbation of the water at frequencies similar to the movements of the zebrafish tail was sufficient to rescue the levels of pth2 in previously isolated fish. These data indicate a previously underappreciated role for the relatively unexplored neuropeptide Pth2 in both tracking and responding to the population density of the social environment of an animal.

In Vivo Modelling of ATP1A3 G316S-Induced Ataxia in C. elegans Using CRISPR/Cas9-Mediated Homologous Recombination Reveals Dominant Loss of Function Defects.

The NIH Undiagnosed Diseases Program admitted a male patient with unclassifiable late-onset ataxia-like symptoms. Exome sequencing revealed a heterozygous de novo mutation converting glycine 316 to serine in ATP1A3, which might cause disease. ATP1A3 encodes the Na+/K+ ATPase pump α3-subunit. Using CRISPR/Cas9-mediated homologous recombination for genome editing, we modelled this putative disease-causing allele in Caenorhabditis elegans, recreating the patient amino acid change in eat-6, the orthologue of ATP1A3. The impact of the mutation on eat-6 function at the neuromuscular junction was examined using two behavioural assays: rate of pharyngeal pumping and sensitivity to aldicarb, a drug that causes paralysis over time via the inhibition of acetylcholinesterase. The patient allele decreased pumping rates and caused hypersensitivity to aldicarb. Animals heterozygous for the allele exhibited similar defects, whereas loss of function mutations in eat-6 were recessive. These results indicate that the mutation is dominant and impairs the neuromuscular function. Thus, we conclude that the de novo G316S mutation in ATP1A3 likely causes or contributes to patient symptoms. More broadly, we conclude that, for conserved genes, it is possible to rapidly and easily model human diseases in C. elegans using CRIPSR/Cas9 genome editing.

Ozônio em morangos minimamente processados, uma alternativa ao uso do cloro na segurança de alimentos / Ozone application on ready-to-eat strawberries a food safety alternative to the chlorine use

O presente trabalho teve como objetivo avaliar o efeito da sanitização por ozonização aquosa e da a cloração na redução da carga microbiana de morangos submetidos ao processamento mínimo. Morangos foram selecionados, lavados em água corrente e submetidos aos tratamentos: T1) Imersão em água ozonizada a 0,2 mg L-1 por 5 min; T2) Imersão em água ozonizada a 0,5 mg L-1 por 5 min; T3) Imersão em água ozonizada a 1,0 mg L-1 por 5 min; T4) Cloração; T5) Controle; T6) Morangos in natura. Posteriormente, os frutos foram processados, drenados, embalados e armazenados em câmara de refrigeração a 5ºC ± 1ºC, por seis dias. As análises microbiológicas para Coliformes a 35ºC (NMP g-1) e Contagem de Fungos Filamentosos e Leveduras (UFC g-1) foram realizadas no dia do processamento. Enquanto que as análises microbiológicas de Enumeração de estafilococos coagulase positiva, Coliformes a 45ºC (NMP g-1), e detecção de Salmonella sp. foram realizadas no dia do processamento e após 6 dias de armazenamento. A carga microbiana de Coliformes totais foi constatada apenas em T6. Os tratamentos com a água ozonizada foram mais eficientes do que o cloro na remoção de fungos filamentosos e Leveduras. A contaminação por Salmonella sp., E. coli, e coliformes 45ºC não foram observada em nenhuma das avaliações.

The objective of this study was to evaluate the efficacy of the sanitization process using aqueous ozone and chlorination in reducing the microbial load on strawberries subjected to minimal processing. Strawberries were selected, washed in tap water, and sanitized using the following treatments: T1) Immersion in aqueous ozone at 0.2 mg/L for 5 min; T2) Immersion in aqueous ozone at 0.5 mg/L for 5 min; T3) Immersion in aqueous ozone at 1.0 mg/L for 5 min; T4) Chlorination; T5) Control; or T6) Strawberries without sanitization (natural). After sanitization, the fruits were processed, drained, packaged, and stored under refrigeration at 5ºC ± 1ºC for 6 days. Microbiological analyses for coliforms at 35ºC (MPN/g) and counts of filamentous fungi and yeasts (CFU/g) were performed on the day of processing. Microbiological enumeration of coagulase-positive staphylococci, coliforms at 45ºC (MPN/g), and detection of Salmonella spp. were performed on the day of processing and again after 6 days of storage. The microbial count of total coliforms was observed only in T6. Treatments with aqueous ozone were more effective than treatment with chlorine in removing filamentous fungi and yeasts. Contamination by Salmonella spp., Escherichia coli, and coliforms at 45ºC was not observed in the analyzed samples.

Inhibition of acetylcholinesterase by two arylderivatives: 3a-Acetoxy-5H-pyrrolo (1,2-a) (3, 1)benzoxazin- 1,5-(3aH)-dione and cis-N-p-Acetoxy-phenylisomaleimide.

Two arylderivatives, 3a-Acetoxy-5H-pyrrolo(1,2-a) (3,1)benzoxazin-1,5-(3aH)-dione 3 and cis-N-p-Acetoxy-phenylisomaleimide 4, were synthesized from anthranilic acid and para-aminophenol, respectively. The inhibitory effects of these compounds on acetylcholinesterase (AChE) activity were evaluated in vitro as well as by docking simulations. Both compounds showed inhibition of AChE activity (Ki = 4.72 +/- 2.3 microM for 3 and 3.6 +/- 1.8 microM for 4) in in vitro studies. Moreover, they behaved as irreversible inhibitors and made pi-pi interaction with W84 and hydrogen bonded with S200 and Y337 according to experimental data and docking calculations. The docking calculations showed deltaG bind (kcal/mol) of - 9.22 for 3 and - 8.58 for 4. These two compounds that can be use as leads for a new family of anti-Alzheimer disease drugs.

p-Aminobenzoic acid derivatives as acetylcholinesterase inhibitors.

Because Alzheimer's disease (AD) is a medical problem characterized by progressive loss of memory and cognition that is associated with a deficient cholinergic system, this work aims to evaluate some p-aminobenzoic acid (PABA) derivatives as acetylcholinesterase inhibitors in vitro, in continuation with our last studies. The assayed compounds are low toxic, simple-structured and low cost.

Ex vivo anticholinesterase activity of benzoic acid derivatives.

p-Aminobenzoic acid (p-ABA) derivatives were evaluated as acetylcholinesterase inhibitors (AChEIs). Finding a correlation between AChE activity with the partition coefficient (log P) and the highest occupied molecular orbital (HOMO) energy of the compounds.