Biology subjects

Viola, M. F.

Publications and source records attributed to Viola, M. F..

3 recordsLinked to original sources

bioRxiv2024

Distinct Dendritic Morphological Changes in the Nucleus Accumbens of Microbiota-deficient Male Mice

The gut microbiota has been shown to be an important regulator of brain and behaviour. Germ-free rodents are a key model to study the microbiome-gut-brain axis to reveal the microbial underpinnings of diseases, including those related to psychiatric illnesses. The present study evaluated whether the absence of gut microbiota could alter the morphological development of the nucleus accumbens, a brain region located in the ventral striatum involved in stress, mood and addiction. In germ-free mice, there was dendritic hypertrophy of medium spiny neurons in the shell and dendritic elongation in the core. This led to an increase in the number of stubby dendritic spines within the shell and an increase in both stubby and thin spines in the core. Taken together, these results indicate that the gut microbiota is essential for the normal development of the dendritic structure of medium spiny neurons in the nucleus accumbens and that altered remodelling may contribute to maladaptive psychiatric disorders.

neuroscience↗

bioRxiv2022

The acute phase response in bats (Carollia perspicillata) varied with the time and dose of the immune-challenge

The acute phase response (APR) is a core component of the innate immune response and represents the first line of immune defense used in response to infections. Although several studies with vertebrates reported fever, decrease in food intake and body mass, as well as increase in neutrophil/lymphocyte ratio and total white blood cell count after lipopolysaccharide (LPS) inoculation there was great variability in the magnitude of these responses. Some of these differences might reflect, to some extent, differences in time of endotoxin inoculation (during activity or resting periods) and dose; however, no study in the literature has evaluated the synergistic effect of these two factors in vertebrates. Therefore, our study tested the interplay between LPS dose and time of injection on selected physiological (fever and increase in total white blood cell count and neutrophil/lymphocyte ratio), and behavioral (food intake) components of APR using a Neotropical fruit-eating bat (Carollia perspicillata) as a model organism. We predicted that LPS would trigger a dose- and time-dependent response on APR components. APR components were assessed in resting and activity periods after injection of three doses of LPS (5, 10 and 15 mg/kg LPS). The results showed that LPS-evoked changes in skin temperature, food intake, neutrophil lymphocyte ratio depend markedly on the LPS dose and/or time that LPS is administered.

physiology↗

bioRxiv2022

Neuro-immune Crosstalk in the Enteric Nervous System from Early Postnatal Development to Adulthood

Correct development and maturation of the enteric nervous system (ENS) is critical for survival. Early in life, the ENS requires significant refinement in order to adapt to the evolving needs of the tissue, changing from milk to solid food at the time of weaning. Here, we demonstrate that resident macrophages of the muscularis externa, MM{phi}, refine the ENS early in life by pruning synapses and phagocytosing abundant enteric neurons. After weaning, MM{phi} continue to closely interact with the ENS, acquire a microglia-like phenotype and are crucial for the survival of enteric neurons. Of note, this microglia-like phenotype is instructed by TGF{beta} produced by the ENS, introducing a novel reciprocal cell-cell communication responsible for the maintenance of the neuron-associated MM[FE] niche in the gut. These findings elucidate a novel role of intestinal macrophages in ENS refinement early in life, and open new opportunities to treat intestinal neurodegenerative disorders by manipulating the ENS-macrophage niche.

immunology↗