Development of the Avian Dorsal Thalamus: Patterns and Gradients of Neurogenesis

The dorsal thalamus is a region of the diencephalon that relays sensory and motor information between areas of the brain stem and the telencephalon. Although a dorsal thalamic region is recognized in all vertebrates and believed to be homologous, little is known about how the regions within it evolved and whether some or all regions within the dorsal thalamus are homologous among different vertebrate species. To characterize the gradients and patterns of neurogenesis of the avian dorsal thalamus, a single application of a low dose of bromodeoxyuridine (BrdU) was delivered to each chick between embryonic day (E)3 and E8 (stages 21 and 34), and chicks were followed up to E8 or E10 (stage 34 or 36). Comparisons of anti-BrdU labeling patterns across the different injection days suggest that nearly all dorsal thalamic neurons are born early in chick embryogenesis, between E3 and E8. Furthermore, neurons in the lateral, dorsal, and posterior parts of the dorsal thalamus are generally born earlier than those in the medial, ventral, and anterior parts. Analyses of the birth dates for nine regions show that the general pattern of neurogenesis in the avian dorsal thalamus resembles that of homologous regions within the rodent thalamus, with the exception of the auditory region, the nucleus ovoidalis, which is born later than the mammalian auditory medial geniculate nucleus. The similar pattern of neurogenesis in birds and mammals may represent a highly conserved developmental pattern that was present in the common ancestor of living birds and mammals, or may represent independently derived states. Additional studies in reptiles and amphibians are needed to distinguish between these evolutionary histories.

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Cranial Nerves and Cranial Nerve Nuclei

10.1093/med/9780190237493.003.0005 ◽

2017 ◽

Author(s):

Peggy Mason

Keyword(s):

Cranial Nerve ◽

Cranial Nerves ◽

Sensory Information ◽

Abducens Nerve ◽

Motor Information ◽

Anatomical Arrangement ◽

Cranial Nerve Injuries ◽

Nerve Dysfunction ◽

The Common ◽

The Brain

The functions of cranial nerves, conduits for sensory information to enter and motor information to exit the brain, and the common complaints arising from cranial nerve injuries are described. The modified anatomical arrangement of sensory and motor territories in the brainstem provides a framework for understanding the organization of the cranial nerve nuclei. A thorough grounding in the anatomy of cranial nerves and cranial nerve nuclei allows the student to deduce whether a given set of symptoms arises from a central or peripheral lesion. The near triad, pupillary light reflex, and Bell’s palsy are particularly emphasized. The contributions of the six extraocular muscles to controlling eye position and to potential diplopia are described along with the consequences of oculomotor, trochlear, and abducens nerve dysfunction. The potential for lesions of facial, glossopharyngeal, vagus, and hypoglossal nerves to yield dysphagia and dysarthria are outlined.

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Advantages of Complementary Stereo Images as Viewed with the Low-Temperature Field-Emission SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131206 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1314-1315

Author(s):

William P. Wergin ◽

Eric F. Erbe

Keyword(s):

Fold Increase ◽

Horizontal Displacement ◽

Three Dimensions ◽

Stereo Image ◽

Stereo Pair ◽

Sem Micrograph ◽

Left And Right ◽

The Common ◽

The Brain ◽

Pair Analysis

The eye-brain complex allows those of us with normal vision to perceive and evaluate our surroundings in three-dimensions (3-D). The principle factor that makes this possible is parallax - the horizontal displacement of objects that results from the independent views that the left and right eyes detect and simultaneously transmit to the brain for superimposition. The common SEM micrograph is a 2-D representation of a 3-D specimen. Depriving the brain of the 3-D view can lead to erroneous conclusions about the relative sizes, positions and convergence of structures within a specimen. In addition, Walter has suggested that the stereo image contains information equivalent to a two-fold increase in magnification over that found in a 2-D image. Because of these factors, stereo pair analysis should be routinely employed when studying specimens.Imaging complementary faces of a fractured specimen is a second method by which the topography of a specimen can be more accurately evaluated.

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The Acute Effect of Alcohol on Various Memory Processes

Journal of Psychophysiology ◽

10.1027/0269-8803/a000038 ◽

2010 ◽

Vol 24 (4) ◽

pp. 249-252 ◽

Cited By ~ 7

Author(s):

Márk Molnár ◽

Roland Boha ◽

Balázs Czigler ◽

Zsófia Anna Gaál

Keyword(s):

Low Dose ◽

Short Term Memory ◽

Acute Effect ◽

Long Term Memory ◽

Term Memory ◽

Memory Processes ◽

Different Types ◽

The Brain ◽

Legal Consequences

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.

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Measuring the World

10.1093/oso/9780198779636.003.0017 ◽

2018 ◽

Author(s):

Ann-Sophie Barwich

Keyword(s):

Sensory Information ◽

Network Models ◽

Model System ◽

Stimulus Input ◽

Expectancy Effects ◽

Neural Network Models ◽

Perceptual Object ◽

External Objects ◽

The Common ◽

The Brain

How much does stimulus input shape perception? The common-sense view is that our perceptions are representations of objects and their features and that the stimulus structures the perceptual object. The problem for this view concerns perceptual biases as responsible for distortions and the subjectivity of perceptual experience. These biases are increasingly studied as constitutive factors of brain processes in recent neuroscience. In neural network models the brain is said to cope with the plethora of sensory information by predicting stimulus regularities on the basis of previous experiences. Drawing on this development, this chapter analyses perceptions as processes. Looking at olfaction as a model system, it argues for the need to abandon a stimulus-centred perspective, where smells are thought of as stable percepts, computationally linked to external objects such as odorous molecules. Perception here is presented as a measure of changing signal ratios in an environment informed by expectancy effects from top-down processes.

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The Dioptrique

10.1093/oso/9780198791713.003.0004 ◽

2017 ◽

Author(s):

Walter Ott

Keyword(s):

Sensory Experience ◽

The Other ◽

Brain Image ◽

Brain Motion ◽

Natural Geometry ◽

The Common ◽

The Brain

Descartes’s treatment of perception in the Optics, though published before the Meditations, contains a distinct account of sensory experience. The end of the chapter suggests some reasons for this oddity, but that the two accounts are distinct is difficult to deny. Descartes in the present work topples the brain image from its throne. In its place, we have two mechanisms, one purely causal, the other inferential. Where the proper sensibles are concerned, the ordination of nature suffices to explain why a given sensation is triggered on the occasion of a given brain motion. The same is true with regard to the common sensibles. But on top of this purely causal story, Descartes re-introduces his doctrine of natural geometry.

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Extending the extended consciousness debate: perception, imagination, and the common kind assumption

Phenomenology and the Cognitive Sciences ◽

10.1007/s11097-021-09738-x ◽

2021 ◽

Author(s):

James Deery

Keyword(s):

Perceptual Experience ◽

Phenomenal Consciousness ◽

Psychological Theory ◽

Predictive Processing ◽

Mental Event ◽

The World ◽

Predictive Approach ◽

The Common ◽

The Relationship ◽

The Brain

AbstractFor some, the states and processes involved in the realisation of phenomenal consciousness are not confined to within the organismic boundaries of the experiencing subject. Instead, the sub-personal basis of perceptual experience can, and does, extend beyond the brain and body to implicate environmental elements through one’s interaction with the world. These claims are met by proponents of predictive processing, who propose that perception and imagination should be understood as a product of the same internal mechanisms. On this view, as visually imagining is not considered to be world-involving, it is assumed that world-involvement must not be essential for perception, and thus internalism about the sub-personal basis is true. However, the argument for internalism from the unity of perception and imagination relies for its strength on a questionable conception of the relationship between the two experiential states. I argue that proponents of the predictive approach are guilty of harbouring an implicit commitment to the common kind assumption which does not follow trivially from their framework. That is, the assumption that perception and imagination are of the same fundamental kind of mental event. I will argue that there are plausible alternative ways of conceiving of this relationship without drawing internalist metaphysical conclusions from their psychological theory. Thus, the internalist owes the debate clarification of this relationship and further argumentation to secure their position.

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Evaluation of the BDNF, NGF, NT3 and NT4 Genes Expressions in the Brains of Neonatal Mice with Hypothyroidism

Journal of Molecular Biology Research ◽

10.5539/jmbr.v7n1p171 ◽

2017 ◽

Vol 7 (1) ◽

pp. 171

Author(s):

Hamid Reza Adeli Bhroz ◽

Kazem Parivar ◽

Iraj Amiri ◽

Nasim Hayati Roodbari

Keyword(s):

Dose Group ◽

Low Dose ◽

Pure Water ◽

Intervention Group ◽

Control Group ◽

High Dose ◽

Endocrine Glands ◽

Blood Samples ◽

High Doses ◽

The Brain

Background and Aim: Thyroid is one of the endocrine glands, (T3 and T4) play a significant role in the development of prenatal brain and the following stages. The study aimed to evaluate the effect of hypothyroidism on the amount of expression of NT4, NT3, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in brain of one-day rat neonates with hypothyroidism.Materials and Methods: In total, 25 mature mice of Albino NMRI race were selected after mating, divided into three group, control, as well as low-dose and high-dose intervention groups. Samples of the control group received pure water during pregnancy, whereas subjects of the intervention group with low and high doses of the medication were administered with 20 mg and 100 mg methimazole powder (dissolved in 100 cc water), respectively. After child delivery, blood samples were obtained from mother mice to determine the level of T3 and T4 in blood serum. Following that, the brain of one-day mice were removed by surgery and assessed to determine the amount of expression of NT4, NT3, NGF and BDNF using the complete kit of RT-PCR.Results: Levels of T4 and T3 in the control group were 28 ug/dl and 1.59 ug/dl, respectively. In the low-dose intervention group, the amounts of the mentioned hormones were 8 ug/dl and 0.85 ug/dl, significantly, indicating a significant reduction in the expression of NT4, NT3, NGF and BDNF genes, compared to the control group. Moreover, T4 and T3 were 6 ug/dl and 0.79 ug/dl in the high-dose group, respectively, conveying a significant decrease in the expression of NT4, NT3, NGF and BDNF genes, compared to the control group (P<0.05).

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The Effect of Long-Term Intranasal Serotonin Treatment on Metabolic Parameters and Hormonal Signaling in Rats with High-Fat Diet/Low-Dose Streptozotocin-Induced Type 2 Diabetes

International Journal of Endocrinology ◽

10.1155/2015/245459 ◽

2015 ◽

Vol 2015 ◽

pp. 1-17 ◽

Cited By ~ 33

Author(s):

Kira V. Derkach ◽

Vera M. Bondareva ◽

Oxana V. Chistyakova ◽

Lev M. Berstein ◽

Alexander O. Shpakov

Keyword(s):

Type 2 Diabetes ◽

High Fat Diet ◽

Low Dose ◽

Diabetic Rats ◽

Brain Serotonin ◽

Serotonin Level ◽

High Fat ◽

Brain Serotonin Level ◽

The Brain

In the last years the treatment of type 2 diabetes mellitus (DM2) was carried out using regulators of the brain signaling systems. In DM2 the level of the brain serotonin is reduced. So far, the effect of the increase of the brain serotonin level on DM2-induced metabolic and hormonal abnormalities has been studied scarcely. The present work was undertaken with the aim of filling this gap. DM2 was induced in male rats by 150-day high-fat diet and the treatment with low dose of streptozotocin (25 mg/kg) on the 70th day of experiment. From the 90th day, diabetic rats received for two months intranasal serotonin (IS) at a daily dose of 20 μg/rat. The IS treatment of diabetic rats decreased the body weight, and improved glucose tolerance, insulin-induced glucose utilization, and lipid metabolism. Besides, it restored hormonal regulation of adenylyl cyclase (AC) activity in the hypothalamus and normalized AC stimulation byβ-adrenergic agonists in the myocardium. In nondiabetic rats the same treatment induced metabolic and hormonal alterations, some of which were similar to those in DM2 but expressed to a lesser extent. In conclusion, the elevation of the brain serotonin level may be regarded as an effective approach to treat DM2 and its complications.

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The C50T polymorphism of the cyclooxygenase-1 gene and the risk of thrombotic events during low-dose therapy with acetyl salicylic acid

Thrombosis and Haemostasis ◽

10.1160/th08-03-0172 ◽

2008 ◽

Vol 100 (07) ◽

pp. 70-75 ◽

Cited By ~ 22

Author(s):

Martijn G. H. van Oijen ◽

Santosh Sundaresan ◽

Marc A. Brouwer ◽

Rene H. M. te Morsche ◽

Wessel Keuper ◽

...

Keyword(s):

Myocardial Infarction ◽

Platelet Aggregation ◽

Primary Endpoint ◽

Low Dose ◽

Cardiovascular Death ◽

Hazard Ratio ◽

Cyclooxygenase 1 ◽

Thromboxane Production ◽

The Common ◽

Cox 1

SummaryAspirin prevents thrombotic events by inhibiting platelet cyclooxygenase-1 (COX-1), thus reducing thromboxane A2 formation and platelet aggregation. The C50T polymorphism of COX-1 is associated with an impaired inhibition of both thromboxane production and in-vitro platelet aggregation by aspirin. We studied whether this polymorphism is also associated with the risk of clinical thrombotic events in patients using aspirin. We included 496 patients admitted to our Coronary Care Unit for various indications treated with aspirin 80 mg daily. Genotyping for the C50T polymorphism demonstrated that 86.7% of the patients had the common genotype, and 13.3% had the variant (12.5% heterozygous, 0.8% homozygous). Baseline variables were well balanced, except that patients with the common genotype more frequently used aspirin prior to admission compared to those patients with the variant genotype. The composite primary endpoint of myocardial infarction, stroke, and/or cardiovascular death occurred in 98 patients (19.8%). Myocardial infarction occurred in 9.6% of patients, stroke in 1.6%, and cardiovascular death in 12.1%.The unadjusted hazard ratio (95% CI) for the primary endpoint for patients with the variant versus the common genotype was 1.07 (0.62–1.85), p=0.8.The adjusted hazard ratio was 0.86 (0.49–1.50), p=0.6. In prior laboratory studies the COX-1 C50T polymorphism was associated with an impaired inhibitory effect of aspirin on thromboxane production and platelet function. However, in this cohort of patients using low-dose aspirin for secondary prevention the polymorphism was not associated with a higher risk of atherothrombotic events.

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