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Serizawa S, Aoki N, Mori C, Fujita T, Yamaguchi S, Matsushima T, Homma KJ. Temporal hampering of thyroid hormone synthesis just before hatching impeded the filial imprinting in domestic chicks. Front Physiol 2023; 14:1084816. [PMID: 36875018 PMCID: PMC9978523 DOI: 10.3389/fphys.2023.1084816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/06/2023] [Indexed: 02/18/2023] Open
Abstract
Thyroid hormones play a critical role in the initiation of the sensitive period of filial imprinting. The amount of thyroid hormones in the brains of chicks increases intrinsically during the late embryonic stages and peaks immediately before hatching. After hatching, a rapid imprinting-dependent inflow of circulating thyroid hormones into the brain occurs via vascular endothelial cells during imprinting training. In our previous study, inhibition of hormonal inflow impeded imprinting, indicating that the learning-dependent inflow of thyroid hormones after hatching is critical for the acquisition of imprinting. However, it remained unclear whether the intrinsic thyroid hormone level just before hatching affects imprinting. Here, we examined the effect of temporal thyroid hormone decrease on embryonic day 20 on approach behavior during imprinting training and preference for the imprinting object. To this end, methimazole (MMI; a thyroid hormone biosynthesis inhibitor) was administered to the embryos once a day on days 18-20. Serum thyroxine (T4) was measured to evaluate the effect of MMI. In the MMI-administered embryos, the T4 concentration was transiently reduced on embryonic day 20 but recovered to the control level on post-hatch day 0. At the beginning of imprinting training on post-hatch day 1, control chicks approached the imprinting object only when the object was moving. In the late phase of training, control chicks subsequently approached towards the static imprinting object. On the other hand, in the MMI-administered chicks, the approach behavior decreased during the repeated trials in the training, and the behavioral responses to the imprinting object were significantly lower than those of control chicks. This indicates that their persistent responses to the imprinting object were impeded by a temporal thyroid hormone decrease just before hatching. Consequently, the preference scores of MMI-administered chicks were significantly lower than those of control chicks. Furthermore, the preference score on the test was significantly correlated with the behavioral responses to the static imprinting object in the training. These results indicate that the intrinsic thyroid hormone level immediately before hatching is crucial for the learning process of imprinting.
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Affiliation(s)
- Shouta Serizawa
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, Itabashi-ku, Tokyo, Japan
| | - Naoya Aoki
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, Itabashi-ku, Tokyo, Japan
| | - Chihiro Mori
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, Itabashi-ku, Tokyo, Japan
| | - Toshiyuki Fujita
- Department of Biological Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, Itabashi-ku, Tokyo, Japan
| | - Shinji Yamaguchi
- Department of Biological Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, Itabashi-ku, Tokyo, Japan
| | - Toshiya Matsushima
- Department of Biology, Faculty of Science, Hokkaido University, Hokkaido, Japan
| | - Koichi J Homma
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, Itabashi-ku, Tokyo, Japan
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Mattsson A, Sjöberg S, Kärrman A, Brunström B. Developmental exposure to a mixture of perfluoroalkyl acids (PFAAs) affects the thyroid hormone system and the bursa of Fabricius in the chicken. Sci Rep 2019; 9:19808. [PMID: 31874986 PMCID: PMC6930258 DOI: 10.1038/s41598-019-56200-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/14/2019] [Indexed: 12/17/2022] Open
Abstract
Perfluoroalkyl acids (PFAAs) are ubiquitous environmental contaminants and eggs and nestlings of raptors and fish-eating birds often contain high levels of PFAAs. We studied developmental effects of a mixture of ten PFAAs by exposing chicken embryos to 0.5 or 3 μg/g egg of each compound in the mixture. Histological changes of the thyroid gland were noted at both doses and increased expression of mRNA coding for type III deiodinase was found at 0.5 μg/g egg. Serum concentrations of the free fraction of thyroid hormones (T3 and T4) were reduced by the PFAA mixture at 3 µg/g egg, which is in line with a decreased synthesis and increased turnover of thyroid hormones as indicated by our histological findings and the decreased mRNA expression of type III deiodinase. The relative weight of the bursa of Fabricius increased at a dose of 3 μg/g egg in females. The bursa is the site of B-cell development in birds and is crucial for the avian adaptive immune system. Analysis of plasma and liver concentrations of the mixture components showed differences depending on chain length and functional group. Our results highlight the vulnerability of the thyroid hormone and immune systems to PFAAs.
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Affiliation(s)
- Anna Mattsson
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden.
| | - Sofia Sjöberg
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
| | - Anna Kärrman
- School of Science and Technology, Örebro University, Örebro, Sweden
| | - Björn Brunström
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
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Takemura Y, Yamaguchi S, Aoki N, Miura M, Homma KJ, Matsushima T. Gene expression of Dio2 (thyroid hormone converting enzyme) in telencephalon is linked with predisposed biological motion preference in domestic chicks. Behav Brain Res 2018; 349:25-30. [PMID: 29704598 DOI: 10.1016/j.bbr.2018.04.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 01/07/2023]
Abstract
Filial imprinting leads to the formation of social attachment if training is performed during a brief sensitive period after hatching. We found that thyroid hormone (3,5,3'-triiodothyronine, T3) acts as a critical determining factor of the sensitive period in domestic chicks. Imprinting upregulates gene expression of the converting enzyme (Dio2, type 2 iodothyronine deiodinase) in the telencephalon, leading to increased brain T3 content. If systemically applied, T3 facilitates imprinting in aged chicks even after the sensitive period is over. Imprinting is also associated with the rapid development of visual perception. Exposure to motion pictures induces a predisposed preference to Johansson's biological motion (BM), and those individuals with higher BM preference are more easily imprinted. Here, we examined whether Dio2 expression is also linked with BM predisposition. Chicks were trained by a rotating red block, and tested for imprinting (experiment 1) and BM preference (experiment 2). To examine the time courses of behavioural and physiological processes, Dio2 expression in telencephalon was compared among three groups: naïve control chicks, and chicks trained for a short (0.5 h) or long period (2 h). In experiment 1, higher Dio2 expression appeared in the 2-h group than in the 0.5-h/control groups, but it was not correlated with the individual imprinting score. In experiment 2, a significant positive correlation appeared between Dio2 expression and BM preference in 2-h-trained chicks. Memory priming by T3 is therefore functionally linked to BM preference induction, leading to successful imprinting to natural objects even when they are initially exposed to artificial objects.
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Affiliation(s)
- Yuri Takemura
- Department of Biology, Faculty of Science, Hokkaido University, N10 W8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
| | - Shinji Yamaguchi
- Department of Life and Health Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Naoya Aoki
- Department of Life and Health Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Momoko Miura
- Department of Biology, Faculty of Science, Hokkaido University, N10 W8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
| | - Koichi J Homma
- Department of Life and Health Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Toshiya Matsushima
- Department of Biology, Faculty of Science, Hokkaido University, N10 W8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan.
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Raymaekers SR, Darras VM. Thyroid hormones and learning-associated neuroplasticity. Gen Comp Endocrinol 2017; 247:26-33. [PMID: 28390960 DOI: 10.1016/j.ygcen.2017.04.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 12/11/2022]
Abstract
Thyroid hormones (THs) are crucial for brain development and maturation in all vertebrates. Especially during pre- and perinatal development, disruption of TH signaling leads to a multitude of neurological deficits. Many animal models provided insight in the role of THs in brain development, but specific data on how they affect the brain's ability to learn and adapt depending on environmental stimuli are rather limited. In this review, we focus on a number of learning processes like spatial learning, fear conditioning, vocal learning and imprinting behavior and on how abnormal TH signaling during development shapes subsequent performance. It is clear from multiple studies that TH deprivation leads to defects in learning on all fronts, and interestingly, changes in local expression of the TH activator deiodinase type 2 seem to have an important role. Taking into account that THs are regulated in a very space-specific manner, there is thus increasing pressure to investigate more local TH regulators as potential factors involved in neuroplasticity. As these learning processes are also important for proper adult human functioning, further elucidating the role of THs in developmental neuroplasticity in various animal models is an important field for advancing both fundamental and applied knowledge on human brain function.
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Affiliation(s)
- Sander R Raymaekers
- Laboratory of Comparative Endocrinology, Biology Department, KU Leuven, Naamsestraat 61, 3000 Leuven, Belgium
| | - Veerle M Darras
- Laboratory of Comparative Endocrinology, Biology Department, KU Leuven, Naamsestraat 61, 3000 Leuven, Belgium.
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Ruuskanen S, Darras VM, Visser ME, Groothuis TGG. Effects of experimentally manipulated yolk thyroid hormone levels on offspring development in a wild bird species. Horm Behav 2016; 81:38-44. [PMID: 27056104 DOI: 10.1016/j.yhbeh.2016.03.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 03/18/2016] [Accepted: 03/19/2016] [Indexed: 10/22/2022]
Abstract
Maternal effects are a crucial mechanism in a wide array of taxa to generate phenotypic variation, thereby affecting offspring development and fitness. Maternally derived thyroid hormones (THs) are known to be essential for offspring development in mammalian and fish models, but have been largely neglected in avian studies, especially in respect to natural variation and an ecological context. We studied, for the first time in a wild species and population, the effects of maternally derived THs on offspring development, behavior, physiology and fitness-related traits by experimental elevation of thyroxine and triiodothyronine in ovo within the physiological range in great tits (Parus major). We found that elevated yolk TH levels had a sex-specific effect on growth, increasing male and decreasing female growth, relative to controls, and this effect was similar throughout the nestling period. Hatching or fledging success, motor coordination behavior, stress reactivity and resting metabolic rate were not affected by the TH treatment. We conclude that natural variation in maternally derived THs may affect some offspring traits in a wild species. As this is the first study on yolk thyroid hormones in a wild species and population, more such studies are needed to investigate its effects on pre-hatching development, and juvenile and adult fitness before generalizations on the importance of maternally derived yolk thyroid hormones can be made. However, this opens a new, interesting avenue for further research in the field of hormone mediated maternal effects.
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Affiliation(s)
- Suvi Ruuskanen
- Section of Ecology, Department of Biology, University of Turku, Finland; Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
| | - Veerle M Darras
- Laboratory of Comparative Endocrinology, Biology Department, KU Leuven, Leuven, Belgium.
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
| | - Ton G G Groothuis
- Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
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Tezuka Y, Herai N, Inomata Y, Kagami K, Yamauchi J, Nishigori H, Sanbe A. Upregulation of inorganic pyrophosphatase 1 as a JNK phosphatase in hypothyroid embryonic chick cerebellum. Life Sci 2015; 128:94-100. [PMID: 25748422 DOI: 10.1016/j.lfs.2015.02.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 02/02/2015] [Accepted: 02/20/2015] [Indexed: 10/23/2022]
Abstract
AIM Thyroid hormones play important roles in vertebrate neuronal development and differentiation. In our previous study, we showed that fetal thyroid dysfunction led to impaired social behaviors of hatchlings on post-hatch day 3, as well as to impaired learning and memory determined by the imprinting preference. However, little is known about the mechanisms underlying the direct adverse effects of fetal thyroid dysfunction on neuronal development. MATERIALS AND METHODS We used a chick embryo as a fetal model to investigate the effects of prenatal exposure to antithyroid drugs on neuronal development in the chick cerebellum. Methimazole (MMI) at a dose of 20μmol/egg was administered to eggs on day 14, while the control was given only a vehicle. In order to address the underlying mechanisms of the impaired behavior, proteomic approaches were employed in the chick cerebellum two days after MMI treatment. KEY FINDINGS In this experiment, we found that inorganic pyrophosphatase 1 (PPA1) was upregulated in the chick cerebellum treated with MMI, and we confirmed this upregulation of PPA1 by Western blot analysis as well as by RT-PCR analysis. Concomitant with the upregulation of PPA1, a marked reduction in JNK activity, as well as of phospho-JNK level, was detected in the MMI-treated chick cerebellum. SIGNIFICANCE Since PPA1 can dephosphorylate JNK, these results suggest that the upregulation of PPA1 during neuronal development in the hypothyroid chick cerebellum may lead to impaired social behaviors as well as to impaired learning and memory via JNK dephosphorylation and inactivation in the chick cerebellum.
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Affiliation(s)
- Yu Tezuka
- Department of Pharmacotherapeutics, School of Pharmacy, Iwate Medical University, Iwate 028-3694, Japan
| | - Natsumi Herai
- Department of Pharmacotherapeutics, School of Pharmacy, Iwate Medical University, Iwate 028-3694, Japan
| | - Yui Inomata
- Department of Pharmacotherapeutics, School of Pharmacy, Iwate Medical University, Iwate 028-3694, Japan
| | - Keisuke Kagami
- Department of Pharmacotherapeutics, School of Pharmacy, Iwate Medical University, Iwate 028-3694, Japan
| | - Junji Yamauchi
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan
| | - Hideo Nishigori
- Department of Pharmacotherapeutics, School of Pharmacy, Iwate Medical University, Iwate 028-3694, Japan
| | - Atsushi Sanbe
- Department of Pharmacotherapeutics, School of Pharmacy, Iwate Medical University, Iwate 028-3694, Japan.
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Nishigori H, Kagami K, Nishigori H. Impaired imprinting and social behaviors in chicks exposed to mifepristone, a glucocorticoid receptor antagonist, during the final week of embryogenesis. Behav Brain Res 2014; 261:134-9. [PMID: 24368142 DOI: 10.1016/j.bbr.2013.11.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 11/21/2013] [Accepted: 11/24/2013] [Indexed: 12/01/2022]
Abstract
UNLABELLED The effects of glucocorticoid receptor dysfunction during embryogenesis on the imprinting abilities and social behaviors of hatchlings were examined using "fertile hen's egg-embryo-chick" system. METHODS AND RESULTS Of embryos treated with mifepristone (0.4μmol/egg) on day 14, over 75% hatched a day later than the controls (day 22) without external anomalies. The mifepristone-treated hatchlings were assayed for imprinting ability on post-hatching day 2 and for social behaviors on day 3. The findings were as follows: imprinting ability (expressed as preference score) was significantly lower in mifepristone-treated hatchlings than in controls (0.65±0.06 vs. 0.92±0.02, P<0.005). Aggregation tests to evaluate the speed (seconds) required for four chicks, individually isolated with cardboard dividers in a box, to form a group after removal of the barriers showed that aggregation was significantly slower in mifepristone-treated hatchlings than in controls (8.7±1.1 vs. 2.6±0.3, P<0.001). In belongingness tests to evaluate the speed (seconds) for a chick isolated at a corner to join a group of three chicks placed at the opposite corner, mifepristone-treated hatchlings took significantly longer than controls (4.5±0.4/40 cm vs. 2.4±0.08/40 cm, P<0.001). In vocalization tests, using a decibel meter to measure average decibel level/30s (chick vocalization), mifepristone-treated hatchlings had significantly weaker vocalizations than controls (14.2±1.9/30s vs. 26.4±1.3/30s P<0.001). In conclusion, glucocorticoid receptor dysfunction during the last week embryogenesis altered the programming of brain development, resulting in impaired behavioral activities in late life.
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Affiliation(s)
- Hideo Nishigori
- Department of Pharmacotherapeutics, School of Pharmacy, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Shiwa-gun, Iwate 028-3694, Japan.
| | - Keisuke Kagami
- Department of Pharmacotherapeutics, School of Pharmacy, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Shiwa-gun, Iwate 028-3694, Japan
| | - Hidekazu Nishigori
- Department of Obstetrics, Tohoku University Hospital, Sendai, Miyagi 980-8575, Japan
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Altered magnetic resonance images of brain and social behaviors of hatchling, and expression of thyroid hormone receptor βmRNA in cerebellum of embryos after Methimazole administration. Psychopharmacology (Berl) 2014; 231:221-30. [PMID: 23949207 DOI: 10.1007/s00213-013-3229-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 07/25/2013] [Indexed: 10/26/2022]
Abstract
RATIONALE AND OBJECTIVES The effects of low thyroid hormone level during embryogenesis on MRI of the brain and social behaviors of hatchlings were examined using "fertilized hen's egg-embryo-chick" system. METHODS AND RESULTS Control and hatchlings treated with methimazole (20 μmol/egg), which hatched 3 days later than controls were examined. The results are as follows: 1. The MRI examination of the midsagittal section of the brain on hatch day showed that the sizes, by T1- and ADC values by diffusion-weighted images, of the optic lobe and cerebellum of the MMI-hatchlings were significantly bigger than those of the controls. 2. The social behaviors on post-hatch day 3 were based on the following tests: (a) Aggregation test: The speed of four chicks, individually isolated by cardboard barriers in a box, to make a group upon the removal of barriers. (b) Belongingness tests: The speed of a chick isolated at a corner to join the group of three chicks placed at the opposite corner. (c) Vocalization test: The number of decibel produced by a chick isolated at a corner using a sound meter. These tests demonstrated that MMI-hatchlings took longer times and had weaker vocalization than the controls, significantly. 3. Upregulation of THRβ mRNA after MMI treatment suggested that THR was necessary for cerebellum development. CONCLUSIONS The MMI exposure during the last week of embryogenesis possibly delayed the myelination of certain brain regions and impaired the social behaviors of hatchlings. The chick embryos can be easily induced with hypothyroidism without maternal influences, and the hatchling's behaviors were analyzed using a video camera. The present method will be useful for assessing the effects of unfavorable influences during embryogenesis on social behaviors in later life.
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Van Herck SLJ, Geysens S, Bald E, Chwatko G, Delezie E, Dianati E, Ahmed RG, Darras VM. Maternal transfer of methimazole and effects on thyroid hormone availability in embryonic tissues. J Endocrinol 2013; 218:105-15. [PMID: 23608220 DOI: 10.1530/joe-13-0089] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Methimazole (MMI) is an anti-thyroid drug used in the treatment of chronic hyperthyroidism. There is, however, some debate about its use during pregnancy as MMI is known to cross the mammalian placenta and reach the developing foetus. A similar problem occurs in birds, where MMI is deposited in the egg and taken up by the developing embryo. To investigate whether maternally derived MMI can have detrimental effects on embryonic development, we treated laying hens with MMI (0.03% in drinking water) and measured total and reduced MMI contents in the tissues of hens and embryos at different stages of development. In hens, MMI was selectively increased in the thyroid gland, while its levels in the liver and especially brain remained relatively low. Long-term MMI treatment induced a pronounced goitre with a decrease in thyroxine (T₄) content but an increase in thyroidal 3,5,3'-triiodothyronine (T₃) content. This resulted in normal T₃ levels in tissues except in the brain. In chicken embryos, MMI levels were similar in the liver and brain. They gradually decreased during development but always remained above those in the corresponding maternal tissues. Contrary to the situation in hens, T₄ availability was only moderately affected in embryos. Peripheral T₃ levels were reduced in 14-day-old embryos but normal in 18-day-old embryos, while brain T₃ content was decreased at all embryonic stages tested. We conclude that all embryonic tissues are exposed to relatively high doses of MMI and its oxidised metabolites. The effect of maternal MMI treatment on embryonic thyroid hormone availability is most pronounced for brain T₃ content, which is reduced throughout the embryonic development period.
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Affiliation(s)
- Stijn L J Van Herck
- Laboratory of Comparative Endocrinology, Department of Biology, KU Leuven, Naamsestraat 61, PB 2464, B-3000 Leuven, Belgium
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Impaired social behavior in chicks exposed to sodium valproate during the last week of embryogenesis. Psychopharmacology (Berl) 2013; 227:393-402. [PMID: 23371491 DOI: 10.1007/s00213-013-2979-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 12/24/2012] [Indexed: 10/27/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate direct exposure to sodium valproate (VPA) during embryogenesis, we administered VPA to chick embryos and examined their social behaviors after hatching. METHODS AND RESULTS Embryos treated with VPA (35 μmol/egg) on day 14 were similar to controls for hatching date (day 21) and hatchlings' abilities, such as motor, imprinting, and surface righting. However, these VPA chicks on posthatching day 3 scored significantly low in the chick's social separation stress (SSS) test as follows. Aggregation test evaluated the speed of four chicks, individually isolated by a cardboard in a box, to aggregate upon removal of the cardboards. Belongingness test evaluated the speed of a chick isolated at a corner to join the group of three chicks placed at the opposite corner. Vocalization test for each chick was performed in an isolated corner by using a sound level meter. The results demonstrated that compared with controls, VPA chicks were significantly slow in aggregation (12.7 ± 2.5 s vs. 2.9 ± 0.9 s, p = 0.006) and belongingness (3.6 ± 0.28 s/40 cm vs. 2.6 ± 0.14 s/40 cm, P = 0.003) and weak in vocalization (13.4 ± 2.8 dB/30 s vs. 26.7 ± 1.3 dB/30 s, P = 0.001), respectively. Weight of cerebellum of VAP chick was 15 % lighter than controls (P = 0.004). CONCLUSIONS Chick embryos exposed to VPA during the last week of embryogenesis had impaired social behaviors in spite of normal mortar and imprinting ability. The present method will be a useful animal model for assessing the effects of environment during embryogenesis on social behaviors in later life.
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De Groef B, Grommen SV, Darras VM. Hatching the cleidoic egg: the role of thyroid hormones. Front Endocrinol (Lausanne) 2013; 4:63. [PMID: 23755041 PMCID: PMC3668268 DOI: 10.3389/fendo.2013.00063] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 05/16/2013] [Indexed: 12/30/2022] Open
Abstract
A major life stage transition in birds and other oviparous sauropsids is the hatching of the cleidoic egg. Not unlike amphibian metamorphosis, hatching in these species can be regarded as a transition from a relatively well-protected "aqueous" environment to a more hazardous and terrestrial life outside the egg, a transition in which thyroid hormones (THs) (often in concert with glucocorticoids) play an important role. In precocial birds such as the chicken, the perihatch period is characterized by peak values of THs. THs are implicated in the control of muscle development, lung maturation and the switch from chorioallantoic to pulmonary respiration, yolk sac retraction, gut development and induction of hepatic genes to accommodate the change in dietary energy source, initiation of thermoregulation, and the final stages of brain maturation as well as early post-hatch imprinting behavior. There is evidence that, at least for some of these processes, THs may have similar roles in non-avian sauropsids. In altricial birds such as passerines on the other hand, THs do not rise significantly until well after hatching and peak values coincide with the development of endothermy. It is not known how hatching-associated processes are regulated by hormones in these animals or how this developmental mode evolved from TH-dependent precocial hatching.
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Affiliation(s)
- Bert De Groef
- Department of Agricultural Sciences, La Trobe University, Melbourne, VIC, Australia
- AgriBio, Centre for AgriBioscience, Melbourne, VIC, Australia
| | - Sylvia V.H. Grommen
- Department of Agricultural Sciences, La Trobe University, Melbourne, VIC, Australia
- AgriBio, Centre for AgriBioscience, Melbourne, VIC, Australia
| | - Veerle M. Darras
- Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
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Abstract
Administration of chemotherapy during pregnancy may represent a big risk factor for the developing brain, therefore we studied whether the transplacental transport of doxorubicin (DOX) may affect the development of neuroendocrine system. DOX (25 mg/kg; 3 times interaperitoneally/week) was given to pregnant rats during whole gestation period. The disturbances in neuroendocrine functions were investigated at gestation day (GD) 15 and 20 by following the maternal and fetal thyroid hormone levels, fetal nucleotides (ATP, ADP, AMP) levels and adenosine triphosphatase (Na(+), K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase) activities in two brain regions, cerebrum and cerebellum. In control group, the levels of maternal and fetal serum thyroxine (T4), triiodothyronine (T3), thyrotropin (TSH), and fetal serum growth hormone (GH) increased from days 15 to 20, whereas in the DOX group, a decrease in maternal and fetal T4, T3 and increase in TSH levels (hypothyroid status) were observed. Also, the levels of fetal GH decreased continuously from GD 15 to 20 with respect to control group. In cerebrum and cerebellum, the levels of fetal nucleotides and the activities of fetal ATPases in control group followed a synchronized course of development. The fetal hypothyroidism due to maternal administration of DOX decreased the levels of nucleotides, ATPases activities, and total adenylate, instead, the adenylate energy charge showed a trend to an increase in both brain regions at all ages tested. These alterations were dose- and age-dependent and this, in turn, may impair the nerve transmission. Finally, DOX may act as neuroendocrine disruptor causing hypothyroidism and fetal brain energetic dysfunction.
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Hamano Y. Alleviative effects ofα-lipoic acid supplementation on acute heat stress-induced thermal panting and the level of plasma nonesterified fatty acids in hypothyroid broiler chickens. Br Poult Sci 2012; 53:125-33. [DOI: 10.1080/00071668.2011.651443] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Haba G, Nishigori H, Tezuka Y, Kagami K, Sugiyama T, Nishigori H. Effect of antithyroid drug on chick embryos during the last week of development: Delayed hatching and decreased cerebellar acetylcholinesterase activity. J Obstet Gynaecol Res 2011; 37:1549-56. [DOI: 10.1111/j.1447-0756.2011.01573.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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