Neurowissenschaften

Bear, Mark F.; Connors, Barry W.; Paradiso, Michael A.

doi:10.1007/978-3-662-49933-7

Cited by 164 publications

(258 citation statements)

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“…This behavior decreased to the level of the CTR calves for the next cycle but steadily increased in subsequent cycles. Our findings in the 4-h a.m. and p.m. analyses are consistent with findings in other studies in which behavioral responses of an individual animal to repeated controllable stressors depended on past experiences with that particular stressor (Bear et al, 2001), and responses were attenuated with repetition of the stressor (Vermetten and Bremner, 2002). The ACTH challenge, when analyzed over 12 h, apparently did not produce a change in behavior of the CTR calves despite an elevated cortisol concentration.…”

supporting

confidence: 93%

Repeated mixing and isolation: Measuring chronic, intermittent stress in Holstein calves

Wilcox

Schutz

Rostagno

et al. 2013

Journal of Dairy Science

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Objectives of this study were to determine the physiological effects of psychological stress applied to dairy calves and to test if molasses consumption could be used to validate that a stressed condition was achieved. Twenty male calves (3 wk old) received jugular catheters and were randomly assigned to control (CTR; n = 4 pens of 1 calf per pen) or social stress treatments (STR; n = 4 pens of 4 calves per pen). The STR treatment included 5 cycles of 24-h isolation followed by regrouping with unfamiliar animals for 48 h (over 15 d). An ACTH challenge (0.1 IU/kg of body weight) was used to determine adrenal fatigue. Peak and total cortisol concentrations were greater for STR calves until the ACTH challenge. After the ACTH challenge, CTR calf cortisol increased and STR calf cortisol continued to decrease, suggesting adrenal fatigue. The number of calves that became positive for fecal shedding of Salmonella after the acute stress of being moved and the number of calves that were positive after the move decreased with each move. Fifty-six percent of STR calves changed from negative to positive for shedding after the first move compared with 18.75% of STR calves remaining negative after the third move. Difference in fecal shedding of Enterobacteriaceae from samples taken before and after moving calves on d 6 was less than that on d 2, 3, and 5. Leukocyte counts were not different, but trends for day effects were detected for neutrophil and monocyte percentages. Molasses consumption was greater for STR calves on d 2 and 11, as was total consumption. Latency to lie after eating also increased as the study progressed; STR calves required more time to lie after eating on d 12 than on d 3, and latency to lie was greater for STR than CTR on d 4, 8, 12, and 14. The STR calves also stood more than the CTR calves in the 4-h afternoon period on d 4, 5, 7, and 14. However, during the 4-h morning observations on d 14 (ACTH challenge), CTR calves stood more than STR calves. This model induced chronic stress, as characterized by adrenal fatigue, which was confirmed by molasses consumption and behavior changes. Therefore, molasses consumption could be used to confirm social stress in experimental models.

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supporting

confidence: 93%

Repeated mixing and isolation: Measuring chronic, intermittent stress in Holstein calves

Wilcox

Schutz

Rostagno

et al. 2013

Journal of Dairy Science

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“…This type of cells fill the space between neurons and were traditionally considered as providing supportive functions to neurons. However, recent studies showed that thy might control the concentration of extracellular molecules, thereby providing important regulatory functions [46-48]. Thus, the difficulty of distinguishing astrocytes with other cells might be due to the fact that they are spatially very close to other major brain cell-types, and they are found in all areas of the brain [46,48,49].…”

Section: Resultsmentioning

confidence: 99%

“…Indeed, oligodendrocytes are examples of well-understood glia in the brain. Their primary function was to insulate the axon and thus expedite the transduction of impulses between neurons by creating the myelin sheath [46,48,49]. Thus, oligodendrocytes mainly reside in the white matter, while neurons mainly reside in the gray matter.…”

Section: Resultsmentioning

confidence: 99%

Automated identification of cell-type-specific genes in the mouse brain by image computing of expression patterns

Zhang

2014

BMC Bioinformatics

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BackgroundDifferential gene expression patterns in cells of the mammalian brain result in the morphological, connectional, and functional diversity of cells. A wide variety of studies have shown that certain genes are expressed only in specific cell-types. Analysis of cell-type-specific gene expression patterns can provide insights into the relationship between genes, connectivity, brain regions, and cell-types. However, automated methods for identifying cell-type-specific genes are lacking to date.ResultsHere, we describe a set of computational methods for identifying cell-type-specific genes in the mouse brain by automated image computing of in situ hybridization (ISH) expression patterns. We applied invariant image feature descriptors to capture local gene expression information from cellular-resolution ISH images. We then built image-level representations by applying vector quantization on the image descriptors. We employed regularized learning methods for classifying genes specifically expressed in different brain cell-types. These methods can also rank image features based on their discriminative power. We used a data set of 2,872 genes from the Allen Brain Atlas in the experiments. Results showed that our methods are predictive of cell-type-specificity of genes. Our classifiers achieved AUC values of approximately 87% when the enrichment level is set to 20. In addition, we showed that the highly-ranked image features captured the relationship between cell-types.ConclusionsOverall, our results showed that automated image computing methods could potentially be used to identify cell-type-specific genes in the mouse brain.

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“…One possible answer, attractive in its parsimony, would be: other competitions, at other levels in a hierarchy . Indeed, in visual object recognition, a converging hierarchical brain organization, as illustrated in Figure 1B, is part of the textbook description (see e.g., Bear et al,2001), with neurons in early visual areas in occipital cortex responding for example to edges of specific orientations at specific spatial locations in the visual field, and neurons in later areas along the ventral pathway down onto the temporal cortex responding to increasingly complex features or objects, with increasingly overlapping spatial receptive fields. (This hierarchical progression, from V1 to IT, is also part of the abovementioned object recognition model of Deco and Rolls, 2004).…”

Section: Shared Brain Mechanisms In Action Selection and Perceptionmentioning

confidence: 99%

Answering questions about consciousness by modeling perception as covert behavior

Markkula

2015

Front. Psychol.

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Two main open questions in current consciousness research concern (i) the neural correlates of consciousness (NCC) and (ii) the relationship between neural activity and first-person, subjective experience. Here, possible answers are sketched for both of these, by means of a model-based analysis of what is required for one to admit having a conscious experience. To this end, a model is proposed that allows reasoning, albeit necessarily in a simplistic manner, about all of the so called “easy problems” of consciousness, from discrimination of stimuli to control of behavior and language. First, it is argued that current neuroscientific knowledge supports the view of perception and action selection as two examples of the same basic phenomenon, such that one can meaningfully refer to neuronal activations involved in perception as covert behavior. Building on existing neuroscientific and psychological models, a narrative behavior model is proposed, outlining how the brain selects covert (and sometimes overt) behaviors to construct a complex, multi-level narrative about what it is like to be the individual in question. It is hypothesized that we tend to admit a conscious experience of X if, at the time of judging consciousness, we find ourselves acceptably capable of performing narrative behavior describing X. It is argued that the proposed account reconciles seemingly conflicting empirical results, previously presented as evidence for competing theories of consciousness, and suggests that well-defined, experiment-independent NCCs are unlikely to exist. Finally, an analysis is made of what the modeled narrative behavior machinery is and is not capable of. It is discussed how an organism endowed with such a machinery could, from its first-person perspective, come to adopt notions such as “subjective experience,” and of there being “hard problems,” and “explanatory gaps” to be addressed in order to understand consciousness.

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Neurowissenschaften

Cited by 164 publications

References 0 publications

Repeated mixing and isolation: Measuring chronic, intermittent stress in Holstein calves

Repeated mixing and isolation: Measuring chronic, intermittent stress in Holstein calves

Automated identification of cell-type-specific genes in the mouse brain by image computing of expression patterns

Answering questions about consciousness by modeling perception as covert behavior

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