scholarly journals Comparative Study of Brain Ontogeny: Marsupials, Humans and Other Eutherians

Author(s):  
Carmen De Miguel ◽  
Arthur Saniotis ◽  
Agata Cieslik ◽  
Maciej Henneberg

Abstract The human brain is commonly considered unique in its growth pattern, especially in its fast growth in early infancy. Consequently, many researchers were encouraged to find peculiarities in the human brain and development which differentiated it from the brains of other animals. In this paper, we argue that the pattern of human brain growth is not different from that of other mammals, both marsupials and eutherians. Thus, our study, challenges the notion of the uniqueness of the human brain and its development indicating that specifically human mental abilities are not a result of brain morphology or size. In order to test our hypothesis we studied the ontogeny of brain weight relative to body weight using pouch young sample of 43 koalas (Phascolarctos cinereus), 28 possums (Trichosurus vulpecula), and 36 tammar wallabies (Macropus eugenii) preserved in a solution of 10 % buffered formalin. We also analysed the growth of brain vs. body size in all eutherian species falling into this group (humans, rhesus monkeys, dogs, cats, rats and mice).

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1326
Author(s):  
Ravneel R. Chand ◽  
Mhairi Nimick ◽  
Belinda Cridge ◽  
Rhonda J. Rosengren

Folivore marsupials, such as brushtail possum (Trichosurus Vulpecula) and koala (Phascolarctos cinereus), can metabolise higher levels of dietary terpenes, such as cineole, that are toxic to eutherian mammals. While the highly efficient drug metabolising enzymes, cytochrome P450 3A (CYP3A) and phase II conjugating enzymes (UDP-glucuronosyltransferase, UGT), are involved in the metabolism of high levels of dietary terpenes, evidence for inhibitory actions on these enzymes by these terpenes is scant. Thus, this study investigated the effect of cineole and its derivatives on catalytic activities of hepatic CYP3A and UGT in mice, rats, and possums. Results showed that cineole (up to 50 µM) and its derivatives (up to 25 µM) did not significantly inhibit CYP3A and UGT activities in mice, rats, and possums (both in silico and in vitro). Interestingly, basal hepatic CYP3A catalytic activity in the possums was ~20% lower than that in rats and mice. In contrast, possums had ~2-fold higher UGT catalytic activity when compared to mice and rats. Thus, these basal enzymatic differences may be further exploited in future pest management strategies.


Author(s):  
Julio H. Garcia ◽  
Janice P. Van Zandt

Repeated administration of methyl alcohol to Rhesus monkeys (Maccaca mulata) by intragastric tube resulted in ultrastructural abnormalities of hepatocytes, which persisted in one animal twelve weeks after discontinuation of the methyl alcohol regime. With dosages ranging between 3.0 to 6.0 gms. of methanol per kg. of body weight, the serum levels attained within a few hours averaged approximately 475 mg. per cent.


Author(s):  
O. L. Orobchenko ◽  
M. Ye. Romanko ◽  
M. O. Yaroshenko ◽  
I. O. Gerilovych ◽  
N. A. Zhukova ◽  
...  

The experiments were performed on 58 males of nonlinear white rats 3–4 months old and weighing 180–200 g and 64 females of nonlinear white mice 2.5–3 months old and weighing 18–22 g. In the main experiment on rats, six experimental groups were formed, the animals of which were injected intragastrically with the drug ‘MEGASTOP for dogs’ (by absolute weight) in doses of 1,000.0, 2,000.0, 3,000.0, 4,000.0, 5,000.0, and 6,000.0 mg/kg body weight; in the main experiment on mice, seven experimental groups were formed, the animals of which were administered the drug in doses of 100.0, 500.0, 1,000.0, 1,500.0, 2,000.0, 2,500.0, and 3,000.0 mg/kg body weight. Control rats and mice were injected with 2.0 cm3 and 0.2 cm3 of polyethylene glycol-400, respectively. Clinical symptoms of poisoning with the drug ‘MEGASTOP for dogs’ of white rats (at doses of 2,000.0–6,000.0 mg/kg body weight) and mice (at doses of 1,000.0–3,000.0 mg/kg body weight) were refusals of food and water, loss of coordination, sitting in one place, a dose-dependent increase in depression with subsequent complete depression, lack of response to external stimuli and death on the first or fourth day after administration. During autopsy in rats and mice that died as a result of poisoning with the drug ‘MEGASTOP for dogs’, we recorded pallor of the mucous membranes of the mouth, trachea, pharynx, and esophagus; increase in heart volume, atrial blood supply; pulmonary hyperemia; uncoagulated blood; increase in liver volume, dark cherry color, flabby consistency; catarrhal inflammation of the mucous membrane of the small intestine. According to the results of determining the parameters of acute toxicity of the drug ‘MEGASTOP for dogs’ in the case of a single intragastric injection, LD50 for male rats is 3,384.98 ± 444.94 mg/kg, and for female mice — 2,025.88 ± 279.46 mg/kg body weight, which allows to classify it to class IV by the toxicity — low-toxic substances (LD50 — 501–5,000 mg/kg) and by the degree of danger to class III— moderately dangerous substances (LD50 — 151–5,000 mg/kg)


1984 ◽  
Vol 32 (2) ◽  
pp. 283 ◽  
Author(s):  
DM Spratt

Seven new taxa in two families of metastrongyloid nematodes are described from the lungs of five host species belonging to the Dasyuridae, Phalangeridae and Macropodidae. Filaroides (Filaroides) athertonensis, sp. nov., (Filaroididae) is described from Thylogale stigmatica Gould in north Queensland. The following species of Marsupostrongylus Mackerras & Sandars, 1953, (Angiostrongylidae) are described as new: M. parallelus, sp. nov., from Satanellus hallucatus (Could) in the Northern Territory; M. pseudominesi, sp. nov., from Trichosurus vulpecula johnstonii (Ramsay) in north Queensland; M. vandiemeni, sp. nov., from macro pus rufogriseus rufogriseus (Desmarest) in Tasmania; and M. wallabiae, sp. nov., from Wallabia bicolor (Desmarest) and Macropus rufogriseus banksianus (Quoy & Gaimard) in New South Wales. To the formerly monotypic genus Filostrongylus Mackenas, 1955, (Angiostrongylidae) is added F. tridendriticus, sp. nov., described from Trichosurus vulpecula (Kerr) in Tasmania. The genus Cosmostrongylus (Angiostrongylidae) is described as new, with a single species C. conspectus, sp. nov., from Thylogale stigmatica Gould in north Queensland. Durikainema sp. (Muspiceoidea: Robertdollfusidae) is diagnosed in histological sections of the lungs of Phascolarctos cinereus (Goldfuss), Macropus agilis (Could) and M. giganteus Shaw. Keys to the genera of lung parasites and to all species of Filaroides, Marsupostrongylus and Filostrongylus known from Australian marsupials, new host and new geographic records of known taxa, and a host-parasite list of lung parasites of Australian marsupials, including those known only from histological sections of lung tissue, are provided.


1954 ◽  
Vol 10 (3) ◽  
pp. 284-290 ◽  
Author(s):  
S. H. GREEN ◽  
S. ZUCKERMAN

SUMMARY An analysis of oocyte numbers in forty-two rhesus monkeys whose ovaries were removed on different days of the menstrual cycle showed (1) that the right and left ovaries usually contain about the same number of oocytes; (2) that oocyte numbers vary inversely with body weight; (3) that there are no significant differences in the total number of oocytes in the early, middle and last thirds of the cycle; and (4) that no constant relation exists between the proportion of follicles in different stages of development.


1975 ◽  
Vol 41 (1) ◽  
pp. 199-204 ◽  
Author(s):  
Charles W. Hill ◽  
Arthur J. Riopelle

Three groups of adult female rhesus monkeys, maintained on low-protein diets (.5 gm, 1 gm, and 2 gm protein per kg body weight) were compared with a control group (4 gm protein per kg body weight) on a food-preference task. Food responsiveness was assessed by presenting 8 small pieces of a certain food, equally spaced about the perimeter of a turntable attached to the home cage, and recording number of pieces taken, number of pieces eaten, and elapsed time for taking all 8 pieces. 21 different foods were used in sequence, 3 each from the following 7 categories: cheese, meat, vegetable, nut, cereal, fruit, and candy. Scores on all 3 measures were highly correlated, and the order of preference was generally the same for all groups. The 2 lowest-protein groups accepted more foods at the lower end of the palatability spectrum than did either the 4-gm or the 2-gm group. There was a tendency for the foods least preferred by the protein-deprived monkeys to be themselves high in protein. Thus, although protein deprivation appears to increase the catholicity of food preference, there is no corresponding increase in the relationship between palatability and protein content.


2020 ◽  
Vol 65 (22) ◽  
pp. 1872-1873
Author(s):  
Bharath Holla ◽  
Jakob Seidlitz ◽  
Richard A.I. Bethlehem ◽  
Gunter Schumann

2019 ◽  
Vol 316 (6) ◽  
pp. H1552-H1557 ◽  
Author(s):  
Quint A. J. Hagdorn ◽  
Guido P. L. Bossers ◽  
Anne-Marie C. Koop ◽  
Arnold Piek ◽  
Tim R. Eijgenraam ◽  
...  

For indexing cardiac measures in small animal models, tibia length (TL) is a recommended surrogate for body weight (BW) that aims to avoid biases because of disease-induced BW changes. However, we question if indexing by TL is mathematically correct. This study aimed to investigate the relation between TL and BW, heart weight, ventricular weights, and left ventricular diameter to optimize the current common practice of indexing cardiac parameters in small animal models. In 29 healthy Wistar rats (age 5–34 wk) and 116 healthy Black 6 mice (age 3–17 wk), BW appeared to scale nonlinearly to TL1 but linearly to TL3. Formulas for indexing cardiac weights were derived. To illustrate the effects of indexing, cardiac weights between the 50% with highest BW and the 50% with lowest BW were compared. The nonindexed cardiac weights differed significantly between groups, as could be expected ( P < 0.001). However, after indexing by TL1, indexed cardiac weights remained significantly different between groups ( P < 0.001). With the derived formulas for indexing, indexed cardiac weights were similar between groups. In healthy rats and mice, BW and heart weights scale linearly to TL3. This indicates that not TL1 but TL3 is the optimal surrogate for BW. New formulas for indexing heart weight and isolated ventricular weights are provided, and we propose a concept in which cardiac parameters should not all be indexed to the same measure but one-dimensional measures to BW1/3 or TL1, two-dimensional measures to BW2/3 or TL2, and three-dimensional measures to BW or TL3. NEW & NOTEWORTHY In healthy rats and mice, body weight (BW) scales linearly to tibia length (TL) to the power of three (TL3). This indicates that for indexing cardiac parameters, not TL1 but TL3 is the optimal surrogate for BW. New formulas for indexing heart weight and isolated ventricular weights are provided, and we propose a concept of dimensionally consistent indexing. This concept is proposed to be widely applied in small animal experiments.


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