Search

Your search keyword '"isotropic fractionation"' showing total 16 results
Start Over Descriptor "isotropic fractionation"
16 results on '"isotropic fractionation"'

1. Proportional Cerebellum Size Predicts Fear Habituation in Chickens.

Author

Stingo-Hirmas, Diego, Cunha, Felipe, Cardoso, Rita France, Carra, Laura G., Rönnegård, Lars, Wright, Dominic, and Henriksen, Rie

Subjects
CEREBELLUM, HABITUATION (Neuropsychology), MOTOR ability, FEAR, CHICKENS, AGE groups
Abstract

The cerebellum has a highly conserved neural structure across species but varies widely in size. The wide variation in cerebellar size (both absolute and in proportion to the rest of the brain) among species and populations suggests that functional specialization is linked to its size. There is increasing recognition that the cerebellum contributes to cognitive processing and emotional control in addition to its role in motor coordination. However, to what extent cerebellum size reflects variation in these behavioral processes within species remains largely unknown. By using a unique intercross chicken population based on parental lines with high divergence in cerebellum size, we compared the behavior of individuals repeatedly exposed to the same fear test (emergence test) early in life and after sexual maturity (eight trials per age group) with proportional cerebellum size and cerebellum neural density. While proportional cerebellum size did not predict the initial fear response of the individuals (trial 1), it did increasingly predict adult individuals response as the trials progressed. Our results suggest that proportional cerebellum size does not necessarily predict an individual's fear response, but rather the habituation process to a fearful stimulus. Cerebellum neuronal density did not predict fear behavior in the individuals which suggests that these effects do not result from changes in neuronal density but due to other variables linked to proportional cerebellum size which might underlie fear habituation. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

2. Proportional Cerebellum Size Predicts Fear Habituation in Chickens

Author

Diego Stingo-Hirmas, Felipe Cunha, Rita France Cardoso, Laura G. Carra, Lars Rönnegård, Dominic Wright, and Rie Henriksen

Subjects
emergence test, behavioral predictability, domestication, neural density, isotropic fractionation, Physiology, QP1-981
Abstract

The cerebellum has a highly conserved neural structure across species but varies widely in size. The wide variation in cerebellar size (both absolute and in proportion to the rest of the brain) among species and populations suggests that functional specialization is linked to its size. There is increasing recognition that the cerebellum contributes to cognitive processing and emotional control in addition to its role in motor coordination. However, to what extent cerebellum size reflects variation in these behavioral processes within species remains largely unknown. By using a unique intercross chicken population based on parental lines with high divergence in cerebellum size, we compared the behavior of individuals repeatedly exposed to the same fear test (emergence test) early in life and after sexual maturity (eight trials per age group) with proportional cerebellum size and cerebellum neural density. While proportional cerebellum size did not predict the initial fear response of the individuals (trial 1), it did increasingly predict adult individuals response as the trials progressed. Our results suggest that proportional cerebellum size does not necessarily predict an individual’s fear response, but rather the habituation process to a fearful stimulus. Cerebellum neuronal density did not predict fear behavior in the individuals which suggests that these effects do not result from changes in neuronal density but due to other variables linked to proportional cerebellum size which might underlie fear habituation.

Published
2022
Full Text
View/download PDF

3. The cellular composition of the marsupial neocortex

Author

Seelke, Adele MH, Dooley, James C, and Krubitzer, Leah A

Subjects
Neurosciences, Neurological, Animals, Auditory Cortex, Cell Count, Female, Male, Monodelphis, Neocortex, Nerve Tissue Proteins, Neurons, Organ Size, Somatosensory Cortex, Visual Cortex, evolution, isotropic fractionation, Zoology, Medical Physiology, Neurology & Neurosurgery
Abstract

In the current investigation we examined the number and proportion of neuronal and non-neuronal cells in the primary sensory areas of the neocortex of a South American marsupial, the short-tailed opossum (Monodelphis domestica). The primary somatosensory (S1), auditory (A1), and visual (V1) areas were dissected from the cortical sheet and compared with each other and the remaining neocortex using the isotropic fractionator technique. We found that although the overall sizes of V1, S1, A1, and the remaining cortical regions differed from each other, these divisions of the neocortex contained the same number of neurons, but the remaining cortex contained significantly more non-neurons than the primary sensory regions. In addition, the percent of neurons was higher in A1 than in the remaining cortex and the cortex as a whole. These results are similar to those seen in non-human primates. Furthermore, these results indicate that in some respects, such as number of neurons, the neocortex is homogenous across its extent, whereas in other aspects of organization, such as non-neuronal number and percentage of neurons, there is non-uniformity. Whereas the overall pattern of neuronal distribution is similar between short-tailed opossums and eutherian mammals, short-tailed opossum have a much lower cellular and neuronal density than other eutherian mammals. This suggests that the high neuronal density cortices of mammals such as rodents and primates may be a more recently evolved characteristic that is restricted to eutherians, and likely contributes to the complex behaviors we see in modern mammals.

Published
2014

4. Proportional Cerebellum Size Predicts Fear Habituation in Chickens

Author

Stingo Hirmas, Diego Vittorio, Barros Da Cunha, Felipe, Cardoso, Rita France, Carra, Laura G., Rönnegård, Lars, Wright, Dominic, and Henriksen, Rie

Subjects
nervous system, Animal and Dairy Science, Medical Bioscience, emergence test, behavioral predictability, domestication, neural density, isotropic fractionation, Zoology, Zoologi
Abstract

The cerebellum has a highly conserved neural structure across species but varies widely in size. The wide variation in cerebellar size (both absolute and in proportion to the rest of the brain) among species and populations suggests that functional specialization is linked to its size. There is increasing recognition that the cerebellum contributes to cognitive processing and emotional control in addition to its role in motor coordination. However, to what extent cerebellum size reflects variation in these behavioral processes within species remains largely unknown. By using a unique intercross chicken population based on parental lines with high divergence in cerebellum size, we compared the behavior of individuals repeatedly exposed to the same fear test (emergence test) early in life and after sexual maturity (eight trials per age group) with proportional cerebellum size and cerebellum neural density. While proportional cerebellum size did not predict the initial fear response of the individuals (trial 1), it did increasingly predict adult individuals response as the trials progressed. Our results suggest that proportional cerebellum size does not necessarily predict an individuals fear response, but rather the habituation process to a fearful stimulus. Cerebellum neuronal density did not predict fear behavior in the individuals which suggests that these effects do not result from changes in neuronal density but due to other variables linked to proportional cerebellum size which might underlie fear habituation. Funding Agencies|Swedish FORMASSwedish Research Council Formas [2019-01508]; European Research CouncilEuropean Research Council (ERC)European Commission [FERALGEN 772874]; Swedish Research CouncilSwedish Research CouncilEuropean Commission; Carl Tryggers Stiftelse; Linkoeping University Neuro-network

Published
2022

5. Impacts of development and adult sex on brain cell numbers in the Black Soldier Fly, Hermetia illucens L. (Diptera: Stratiomyidae).

Author

Barrett, Meghan, Godfrey, R. Keating, Sterner, Emily J., and Waddell, Edward A.

Subjects
*HERMETIA illucens, *GERM cells, *SIMULIIDAE, *DIPTERA, *ADULT development, *SEXUAL dimorphism, *BODY size
Abstract

The Black Soldier Fly (Hermetia illucens , Diptera: Stratiomyidae) has been introduced across the globe, with numerous industry applications predicated on its tremendous growth during the larval stage. However, basic research on H. illucens biology (for example, studies of their central nervous system) are lacking. Despite their small brain volumes, insects are capable of complex behaviors; understanding how these behaviors are completed with such a small amount of neural tissue requires understanding processing power (e.g. number of cells) within the brain. Brain cell counts have been completed in only a few insect species (mostly Hymenoptera), and almost exclusively in adults. This limits the taxonomic breadth of comparative analyses, as well as any conclusions about how development and body size growth may impact brain cell populations. Here, we present the first images and cell counts of the H. illucens brain at four time points across development (early, mid, and late larval stages, and both male and female adults) using immunohistochemistry and isotropic fractionation. To assess sexual dimorphism in adults, we quantified the number of cells in the central brain vs. optic lobes of males and females separately. To assess if increases in body size during development might independently affect different regions of the CNS, we quantified the larval ventral nerve cord and central brain separately at all three stages. Together, these data provide the first description of the nervous system of a popular, farmed invertebrate and the first study of brain cell numbers using IF across developmental stages in any insect. • 8.8-fold increase in brain cell number for black soldier flies during larval development. • 16.2-fold increase in brain cell number for black soldier flies during pupation. • Adult males have more brain cells in their optic lobes than adult females. • Number of cells in the protocerebrum is not different between males and females. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

6. Differential changes in the cellular composition of the developing marsupial brain.

Author

Seelke, Adele M.H., Dooley, James C., and Krubitzer, Leah A.

Abstract

Throughout development both the body and the brain change at remarkable rates. Specifically, the number of cells in the brain undergoes dramatic nonlinear changes, first exponentially increasing in cell number and then decreasing in cell number. Different cell types, such as neurons and glia, undergo these changes at different stages of development. The current investigation used the isotropic fractionator method to examine the changes in cellular composition at multiple developmental milestones in the short-tailed opossum, Monodelphis domestica. Here we report several novel findings concerning marsupial brain development and organization. First, during the later stages of neurogenesis (P18), neurons make up most of the cells in the neocortex, although the total number of neurons remains the same throughout the life span. In contrast, in the subcortical regions, the number of neurons decreases dramatically after P18, and a converse relationship is observed for nonneuronal cells. In the cerebellum, the total number of cells gradually increases until P180 and then remains constant, and then the number of neurons is consistent across the developmental ages examined. For the three major structures examined, neuronal density and the percentage of neurons within a structure are highest during neurogenesis and then decrease after this point. Finally, the total number of neurons in the opossum brain is relatively low compared with other small-brained mammals such as mice. The relatively low number of neurons and correspondingly high number of nonneurons suggests that in the marsupial brain nonneurons may play a significant role in signal processing. J. Comp. Neurol. 521:2602-2620, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Published
2013
Full Text
View/download PDF

7. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

8. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

9. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

10. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

11. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

12. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

13. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

14. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

15. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

16. The effects of domestication on cerebellar morphology and brain composition: comparing wild rats (Rattus norvegicus) to laboratory rats

Abstract

The laboratory rat, the domestic version of the wild Norway rat (Rattus norvegicus), is an important model organism in scientific research. Like other domestic mammals, laboratory rats have smaller brains than their wild relatives. Little is known, however, about the effects of domestication on cerebellar morphology or the underlying changes in cellular composition responsible for such intraspecific variation in brain morphology. Here, we compared cerebellar morphology and brain composition in wild rats and two domestic laboratory strains: Long-Evans and Sprague-Dawley. In the cerebellum, we found that all strains had similar Purkinje cell numbers, but wild rats had a higher degree of foliation and larger Purkinje somas than Long-Evans rats. Next, we used isotropic fractionation to test for differences in brain composition across strains. We found that brain composition differs between laboratory and wild rats, but that the effects of domestication vary across strains and brain regions.

Published
2018

Catalog

Books, media, physical & digital resources
See catalog results