ORCID Profile
0000-0002-7949-5725
Current Organisations
Florey Institute of Neuroscience and Mental Health
,
University of Melbourne
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: ZappyLab, Inc.
Date: 24-01-2022
Publisher: Springer Science and Business Media LLC
Date: 12-04-2021
DOI: 10.1038/S41598-021-86917-5
Abstract: Parkinson’s disease (PD) is associated with neuronal damage in the brain and gut. This work compares changes in the enteric nervous system (ENS) of commonly used mouse models of PD that exhibit central neuropathy and a gut phenotype. Enteric neuropathy was assessed in five mouse models: peripheral injection of MPTP intracerebral injection of 6-OHDA oral rotenone and mice transgenic for A53T variant human α-synuclein with and without rotenone. Changes in the ENS of the colon were quantified using pan-neuronal marker, Hu, and neuronal nitric oxide synthase (nNOS) and were correlated with GI function. MPTP had no effect on the number of Hu+ neurons but was associated with an increase in Hu+ nuclear translocation (P 0.04). 6-OHDA lesioned mice had significantly fewer Hu+ neurons/ganglion (P 0.02) and a reduced proportion of nNOS+ neurons in colon (P 0.001). A53T mice had significantly fewer Hu+ neurons/area (P 0.001) and exhibited larger soma size (P 0.03). Treatment with rotenone reduced the number of Hu+ cells/mm 2 in WT mice (P 0.006) and increased the proportion of Hu+ translocated cells in both WT (P 0.02) and A53T mice (P 0.04). All PD models exhibited a degree of enteric neuropathy, the extent and type of damage to the ENS, however, was dependent on the model.
Publisher: Wiley
Date: 26-04-2020
DOI: 10.1111/NMO.13866
Publisher: Bioscientifica
Date: 06-2019
DOI: 10.1530/JOE-19-0109
Abstract: Chronic stress is a known suppressor of female reproductive function. However, attempts to isolate single causal links between stress and reproductive dysfunction have not yet been successful due to their multi-faceted aetiologies. The gut-derived hormone ghrelin regulates stress and reproductive function and may therefore be pivotal in the neuroendocrine integration of the hypothalamic–pituitary–adrenal (HPA) and –gonadal (HPG) axes. Here, we hypothesised that chronic stress disrupts ovarian follicle maturation and that this effect is mediated by a stress-induced increase in acyl ghrelin and activation of the growth hormone secretatogue receptor (GHSR). We gave C57BL/6J female mice 30 min daily chronic predator stress for 4 weeks, or no stress, and gave them daily GHSR antagonist ( d -Lys3-GHRP-6) or saline. Exposure to chronic predator stress reduced circulating corticosterone, elevated acyl ghrelin levels and led to significantly depleted primordial follicle numbers. GHSR antagonism stress-dependently altered the expression of genes regulating ovarian responsiveness to gonadotropins and was able to attenuate the stress-induced depletion of primordial follicles. These findings suggest that chronic stress-induced elevations of acyl ghrelin may be detrimental for ovarian follicle maturation.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2023
Publisher: Wiley
Date: 10-11-2019
DOI: 10.1111/NMO.13755
Abstract: Chronic stress exacerbates motor deficits and increases dopaminergic cell loss in several rodent models of Parkinson's disease (PD). However, little is known about effects of stress on gastrointestinal (GI) dysfunction, a common non‐motor symptom of PD. We aimed to determine whether chronic stress exacerbates GI dysfunction in the A53T mouse model of PD and whether this relates to changes in α‐synuclein distribution. Chronic isolation stress was induced by single‐housing WT and homozygote A53T mice between 5 and 15 months of age. GI and motor function were compared with mice that had been group‐housed. Chronic isolation stress increased plasma corticosterone and exacerbated deficits in colonic propulsion and whole‐gut transit in A53T mice and also increased motor deficits. However, our results indicated that the novel environment‐induced defecation response, a common method used to evaluate colorectal function, was not a useful test to measure exacerbation of GI dysfunction, most likely because of the reported reduced level of anxiety in A53T mice. A53T mice had lower corticosterone levels than WT mice under both housing conditions, but single‐housing increased levels for both genotypes. Enteric neuropathy was observed in aging A53T mice and A53T mice had a greater accumulation of alpha‐synuclein (αsyn) in myenteric ganglia under both housing conditions. Chronic isolation stress exacerbates PD‐associated GI dysfunction, in addition to increasing motor deficits. However, these changes in GI symptoms are not directly related to corticosterone levels, worsened enteric neuropathy, or enteric αsyn accumulation.
Publisher: Wiley
Date: 08-06-2020
DOI: 10.1111/NMO.13893
Publisher: Wiley
Date: 13-03-2023
DOI: 10.1111/NMO.14560
Abstract: The common occurrence of gastric disorders, the accelerating emphasis on the role of the gut‐brain axis, and development of realistic, predictive models of gastric function, all place emphasis on increasing understanding of the stomach and its control. However, the ways that regions of the stomach have been described anatomically, physiologically, and histologically do not align well. Mammalian single compartment stomachs can be considered as having four anatomical regions fundus, corpus, antrum, and pyloric sphincter. Functional regions are the proximal stomach, primarily concerned with adjusting gastric volume, the distal stomach, primarily involved in churning and propelling the content, and the pyloric sphincter that regulates passage of chyme into the duodenum. The proximal stomach extends from the dome of the fundus to a circumferential band where propulsive waves commence (slow waves of the pacemaker region), and the distal stomach consists of the pacemaker region and the more distal regions that are traversed by waves of excitation, that travel as far as the pyloric sphincter. Thus, the proximal stomach includes the fundus and different extents of the corpus, whereas the distal stomach consists of the remainder of the corpus and the antrum. The distributions of aglandular regions and of specialized glands, such as oxyntic glands, differ vastly between species and, across species, have little or no relation to anatomical or functional regions. It is hoped that this review helps to clarify nomenclature that defines gastric regions that will provide an improved basis for drawing conclusions for different investigations of the stomach.
Publisher: IEEE
Date: 11-07-2022
Publisher: Springer Science and Business Media LLC
Date: 11-02-2022
DOI: 10.1007/S00441-022-03594-0
Abstract: We investigated the distributions and targets of nitrergic neurons in the rat stomach, using neuronal nitric oxide synthase (NOS) immunohistochemistry and nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry. Nitrergic neurons comprised similar proportions of myenteric neurons, about 30%, in all gastric regions. Small numbers of nitrergic neurons occurred in submucosal ganglia. In total, there were ~ 125,000 neuronal nitric oxide synthase (nNOS) neurons in the stomach. The myenteric cell bodies had single axons, type I morphology and a wide range of sizes. Five targets were identified, the longitudinal, circular and oblique layers of the external muscle, the muscularis mucosae and arteries within the gastric wall. The circular and oblique muscle layers had nitrergic fibres throughout their thickness, while the longitudinal muscle was innervated at its inner surface by fibres of the tertiary plexus, a component of the myenteric plexus. There was a very dense innervation of the pyloric sphincter, adjacent to the duodenum. The muscle strands that run between mucosal glands rarely had closely associated nNOS nerve fibres. Both nNOS immunohistochemistry and NADPH histochemistry showed that nitrergic terminals did not provide baskets of terminals around myenteric neurons. Thus, the nitrergic neuron populations in the stomach supply the muscle layers and intramural arteries, but, unlike in the intestine, gastric interneurons do not express nNOS. The large numbers of nNOS neurons and the density of innervation of the circular muscle and pyloric sphincter suggest that there is a finely graded control of motor function in the stomach by the recruitment of different numbers of inhibitory motor neurons.
Publisher: Wiley
Date: 07-11-2021
DOI: 10.1111/JOA.13587
Abstract: The strengths, directions and coupling of the movements of the stomach depend on the organisation of its musculature. Although the rat has been used as a model species to study gastric function, there is no detailed, quantitative study of the arrangement of the gastric muscles in rat. Here we provide a descriptive and quantitative account, and compare it with human gastric anatomy. The rat stomach has three components of the muscularis externa, a longitudinal coat, a circular coat and an internal oblique (sling) muscle in the region of the gastro–oesophageal junction. These layers are similar to human. Unlike human, the rat stomach is also equipped with paired muscular oesophago‐pyloric ligaments that lie external to the longitudinal muscle. There is a prominent muscularis mucosae throughout the stomach and strands of smooth muscle occur in the mucosa, between the glands of the corpus and antrum. The striated muscle of the oesophageal wall reaches to the stomach, unlike the human, in which the wall of the distal oesophagus is smooth muscle. Thus, the continuity of gastric and oesophageal smooth muscle bundles, that occurs in human, does not occur in rat. Circular muscle bundles extend around the circumference of the stomach, in the fundus forming a cap of parallel muscle bundles. This arrangement favours co‐ordinated circumferential contractions. Small bands of muscle make connections between the circular muscle bundles. This is consistent with a slower conduction of excitation orthogonal to the circular muscle bundles, across the corpus towards the distal antrum. The oblique muscle merged and became continuous with the circular muscle close to the gastro–oesophageal junction at the base of the fundus, and in the corpus, lateral to the lesser curvature. Quantitation of muscle thickness revealed gradients of thickness of both the longitudinal and circular muscle. This anatomical study provides essential data for interpreting gastric movements.
Publisher: Springer Science and Business Media LLC
Date: 06-11-2020
Publisher: ZappyLab, Inc.
Date: 24-01-2022
Publisher: Elsevier BV
Date: 09-2021
Publisher: ZappyLab, Inc.
Date: 10-01-2022
Location: Australia
No related grants have been discovered for Madeleine Rose Di Natale.