scispace - formally typeset
Search or ask a question

How many neurons does a squirrel have? 

Answers from top 9 papers

More filters
Papers (9)Insight
Ail of these studies indicate a belief that the antelope ground squirrel has an all-cone retina; indeed.
Overall, the 5‐HT innervation of the thalamus in the squirrel monkey was more massive than would have been expected from earlier studies in nonprimate species.
Moreover, the almost total lack of Müller cell and RPE reactivity in the ground squirrel retina is a significant difference from results in other species.
Recordings from a second class of cells in the outer retina of the squirrel reveal receptive-field properties considerably different from those of squirrel horizontal cells and similar to those of photoreceptor cells in other species.
Unlike many mammals, most squirrel species are diurnal with cone-dominated retinas, similar to the primate fovea, and have excellent dichromatic color vision that is mediated by green and blue cones.
These results reveal that the PPN gives rise to a massive and highly ordered innervation of the basal ganglia in the squirrel monkey.
We have found that the brains of the spiny rat, squirrel, prairie dog and rabbit conform to the neuronal scaling rules that apply to the previous sample of rodents.
Their presence in the squirrel monkey cortex, known to have high secretory activity, lends credence to the correlation of hyperdevelopment of the agranular reticulum with increased rates of secretion of corticoids.
These results indicate that the beta 4 nAChR subunit is expressed by specific subtypes of neurons on the ground squirrel retina.

See what other people are reading

How does Epac impact on nf-kappaB function?
5 answers
Epac (Exchange proteins directly activated by cAMP) plays a crucial role in modulating NF-kappaB function. Epac activation by cAMP involves structural changes that differ from the classic cAMP receptor, PKA, suggesting unique mechanisms of action. Epac1, a specific isoform, has been implicated in inhibiting key inflammatory mediators like TNF-α and IL-1β, indicating a protective role in the retina against inflammatory responses. NF-kappaB, a transcription factor activated by oxidative stress, is known to be regulated by various factors, including vitamin E, which inhibits NF-kappaB activation, potentially through reducing oxidative stress. Understanding the intricate regulation of NF-kappaB is crucial due to its involvement in diverse cellular responses, including immune, inflammatory, and apoptotic pathways, with implications for inflammatory diseases and cancer therapies. Epac proteins, including Epac1, serve as novel cAMP sensors that regulate inflammation and cellular processes through diverse effectors, highlighting their multifaceted roles in cellular signaling.
Does caffeine reduce IL-1 and IL-6 in inflammation?
4 answers
Caffeine has been shown to reduce IL-1 and IL-6 levels in inflammation. In a study on mice, caffeine administration before lipopolysaccharide (LPS) induction decreased the expression of IL-1β, IL-6, and TNF-α, while increasing IL-10 and IL-13, indicating an anti-inflammatory effect. Similarly, in retinal inflammation models, caffeine reduced IL-6 levels and restored physiological levels of BDNF, suggesting a protective role against inflammation. Furthermore, in a study on well-trained male athletes, caffeine supplementation led to higher IL-6 and IL-10 levels after exercise, indicating an enhanced response to physical activity. These findings collectively support the notion that caffeine can effectively reduce IL-1 and IL-6 levels in inflammatory conditions.
How much data is required to train RetinaNet?
4 answers
Training RetinaNet, a deep learning model for tasks like diagnosing eye diseases from retinal images, typically requires a significant amount of data. However, recent research has shown advancements in training deep learning models with limited datasets. For instance, a study proposed a Coherent Network (CoNet) for joint segmentation of retinal layers using less than a hundred training samples, achieving superior performance. Another approach involved a self-supervised training scheme that accurately predicted retinal thickness measurements from unlabeled cross-modal medical imaging data, outperforming traditional classifiers with scarce training data. Additionally, generative deep learning techniques have been explored to synthesize large datasets of artificial retina images, aiding in training diagnostic models without the need for extensive human-graded datasets. These innovative methods showcase the potential to train RetinaNet effectively with varying amounts of data.
What specific brain areas induce rhythmic activity in v1?
5 answers
Rhythmic activity in the primary visual cortex (V1) is induced by feedback projections from higher visual areas, such as mid- to high-level cortical association areas. This feedback plays a crucial role in modulating neural oscillations, including gamma rhythms (30-80 Hz), which are synchronized with action potentials of nearby neurons in V1. The interaction between V1 and higher visual areas is essential for generating and maintaining these rhythmic activities, as demonstrated by the significant decrease in gamma rhythms and visually evoked potentials in V1 when feedback projections are inactivated. Therefore, while V1 itself is involved in processing visual information, the rhythmic activities within V1 are strongly influenced by feedback from other brain regions, highlighting the complex network dynamics involved in visual perception and processing.
How does myopia develop and progress over time?
4 answers
Myopia development and progression involve a combination of genetic and environmental factors. Factors like lifestyle changes, screen time, genetic predisposition, and near work contribute to the onset and progression of myopia. Studies show that myopia prevalence has significantly increased, especially among younger generations, with a peak prevalence in the 1980s. Younger age, female sex, and certain racial/ethnic groups are associated with faster myopic progression. Various interventions like outdoor activities, specific eyeglasses, contact lenses, and pharmacological treatments are being explored to control myopia progression. Understanding these factors and implementing appropriate interventions are crucial in managing myopia and reducing its sight-threatening complications over time.
How does mental fatigue impact cognitive function and performance in various tasks?
4 answers
Mental fatigue significantly impacts cognitive function and performance in various tasks. Studies have shown that prolonged cognitive activity without adequate intellectual resources leads to changes in mood, motivation, and temporary deterioration of cognitive functions involved in goal-directed behavior. Research indicates that mental fatigue can result in decreased cognitive performance, affecting response time and behavioral performance. Furthermore, mental fatigue can lead to a subjective sensation of mental weariness, reducing cognitive abilities and impacting physical performance, such as endurance and balance. Additionally, fatigue-induced changes in cognitive function have been correlated with alterations in knee mechanics during cognitively challenging movements, highlighting the interconnectedness of mental fatigue, cognitive performance, and physical outcomes.
Which fossil fish brains have been analyzed to date, and what conclusions have been drawn from these studies?
5 answers
Fossil fish brains that have been analyzed include those of Coccocephalichthys wildi, a ~319-million-year-old ray-finned fish. Studies on lungfish have shown significant variation in brain shape evolution, particularly in the forebrain and inner ear regions. These analyses have revealed differences in the distribution of SATB1 and SATB2 proteins between sarcopterygian and actinopterygian fishes, with lungfish displaying unique expression patterns in various brain regions. Additionally, research on Astyanax mexicanus has highlighted evolutionary changes in brain structure and function associated with environmental perturbations, such as hindbrain and hypothalamic expansion, and alterations in neurotransmitter systems in blind cavefish populations.
How does the expression of ankyrin 3 differ in individuals with autism compared to those without?
5 answers
Individuals with autism spectrum disorder (ASD) exhibit alterations in the expression of ankyrin 3 (ANK3) compared to those without ASD. ANK3 mutations have been linked to neuropsychiatric disorders, cognitive impairments, and neurodevelopmental conditions. In the context of ASD, mutations in synapse-associated genes like SH3 and multiple ankyrin repeat domains protein 3 (SHANK3) are implicated. Ankyrin-G, encoded by ANK3, plays a crucial role in neuronal development and is involved in localizing proteins within neurons, impacting brain function. Studies have shown that individuals with ASD demonstrate differences in various components of written expression, such as length, legibility, handwriting size, speed, spelling, and overall structure, emphasizing distinct characteristics in their writing skills compared to typically developing peers. These findings collectively suggest that ANK3 expression variations contribute to the unique neurodevelopmental features observed in individuals with ASD.
What can be a problem statement for light pollution?
5 answers
Light pollution poses a significant problem statement encompassing various aspects. It adversely affects astronomy research, wildlife, ecosystems, and human health. The excessive and improper use of artificial lighting in urban areas contributes to visual discomfort, environmental damage, and health issues. The toxicity of blue light emitted by LEDs can lead to retinal damage and disrupt the synthesis of melatonin, impacting the internal clock and potentially causing degenerative diseases. Furthermore, light pollution results in glare, trespass, and sky glow, affecting the environment through scattering artificial light in the atmosphere, with certain light sources like LED advertising billboards having a more pronounced impact. Addressing these issues requires a comprehensive approach to mitigate the detrimental effects of light pollution on various fronts.
Who proposed the landscape of fear theory?
4 answers
The Landscape of Fear (LOF) theory was proposed by Marcos Moleón and José A. Sánchez-Zapata, who highlighted that animals shape their spatial behavior based on perceived and predicted risks from predators, creating a dynamic 'landscape of fear' unique to each species and individual. This concept emphasizes that predator activity and the subsequent risk of predation can be influenced by natural cycles related to Earth's rotation and orbits, making it predictable. Additionally, the LOF theory has been further developed to show how predator cues, such as chemical signals, can disrupt prey behaviors like foraging, affecting distribution and anti-predation responses. Furthermore, human-induced changes can also alter risk perception and responses in wildlife, contributing to dynamic landscapes of fear.
Visual acuity in predatory birds vs songbirds?
5 answers
Predatory birds, such as swallows, exhibit unique visual adaptations for hunting in flight, including bifoveate retinas, long eyes for enhanced spatial resolution, and specialized foveae for acute frontal vision. In contrast, songbirds like budgerigars and European starlings have different visual acuities and field configurations. Budgerigars show lower acuity for moving single targets compared to gratings, indicating varying acuity levels for different stimuli. European starlings, with higher visual acuity and wider blind areas, display distinct antipredator responses influenced by their visual properties, affecting predator detection probabilities and vigilance behavior. These differences in visual systems between predatory and songbirds reflect adaptations to their respective hunting strategies and ecological niches, emphasizing the importance of acute frontal vision in pursuit predators like swallows.