UNASSIGNED: Stroke is a highly prevalent and devastating condition affecting millions worldwide. The Devil\'s Claw (DCW) plant is a native African plant whose anti-inflammatory, antioxidant, and neuroprotective properties have been investigated. We postulated that DCW could protect the brain injury caused by cerebral ischemia.
UNASSIGNED: The rats were randomly divided into four groups. The sham and control (Ctrl) groups received pretreatment with a distilled water vehicle. Doses of 200 and 400 mg/kg were selected for pretreatment with DCW. The filament or intravascular occlusion method was used for middle cerebral artery occlusion (MCAO). The Triphenyl tetrazolium chloride (TTC) staining method was used to investigate the infarct zone and penumbra volume. The neuroprotective effect of DCW was measured by hematoxylin staining. Movement performance was evaluated from neurological deficit score, rotarod performance, and open field tests.
UNASSIGNED: TTC staining showed that the DCW/400 group could maintain the penumbra\'s structure and reduce the infarct volume compared to the Ctrl group (p<0.001). Histological studies confirmed the neuroprotective properties of DCW at doses of 200 and 400 mg/kg compared to the Ctrl group (p<0.01 and p<0.0001, respectively). The results of behavioral tests showed an improvement in behavioral performance in pretreatment 400 mg/kg doses compare to Ctrl group (p<0.0001).
UNASSIGNED: The study showed that pretreatment with DCW with its neuron protection potential reduces the infarct area and restores motor function after MCAO.

Alzheimer\'s disease is characterized by progressive memory loss caused from alterations in the central cholinergic system. While existing medications often have adverse effects, traditional use of Tiliacora triandra in Thailand shows its potential as a revitalizing neurotonic agent. This study explores the impact of T. triandra leaf extract on cognitive behaviors, neuronal density, and oxidative stress in male rats with scopolamine-induced cognitive impairment. Experimental groups composed of a control, vehicle, positive control meditation, and T. triandra extract-treated groups (100, 200, and 400 mg/kg BW) over 14 days, with scopolamine administration (i.p.) between days 8 and 14. Results showed significant enhancements in the discrimination ratio and spontaneous alteration behavior percentage during novel object recognition (NORT) and Y-maze tests for scopolamine-administered rats treated with T. triandra extract or donepezil. In contrast, open field test (OFT)-assessed spontaneous locomotor activity displayed no significant difference. Notably, acetylcholinesterase (AChE) activity and malondialdehyde (MDA) levels reduced significantly in scopolamine-treated rats with T. triandra extract or the positive control. Moreover, neuronal density in the hippocampal CA3 region, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities increased significantly. However, catalase (CAT) activity exhibited no significant difference. In conclusion, T. triandra leaf extract shows promise in mitigating scopolamine-induced memory deficits, potentially attributed to increased neuronal density, inhibited AChE activity, reduced MDA levels, and enhanced antioxidant activities. This extract has potential as a therapeutic agent for Alzheimer\'s disease-associated memory impairment.

UNASSIGNED: The Notch pathway is fundamental for the generation of neurons during development. We previously reported that adult mice heterozygous for the null allele of the gene encoding the Delta-like ligand 1 for Notch (Dll1lacZ ) have a reduced neuronal density in the substantia nigra pars compacta. The aim of the present work was to evaluate whether this alteration extends to other brain structures and the behavioral consequences of affected subjects.
UNASSIGNED: Brains of Dll1 +/lacZ embryos and mice at different ages were phenotypically compared against their wild type (WT) counterpart. Afterwards, brain histological analyses were performed followed by determinations of neural cell markers in tissue slices. Neurological deficits were diagnosed by applying different behavioral tests to Dll1 +/lacZ and WT mice.
UNASSIGNED: Brain weight and size of Dll1 +/lacZ mice was significantly decreased compared with WT littermates (i.e., microcephaly), a phenotype detected early after birth. Interestingly, enlarged ventricles (i.e., hydrocephalus) was a common characteristic of brains of Dll1 haploinsufficient mice since early ages. At the cell level, general cell density and number of neurons in several brain regions, including the cortex and hippocampus, of Dll1 +/lacZ mice were reduced as compared with those regions of WT mice. Also, fewer neural stem cells were particularly found in the adult dentate gyrus of Dll1 +/lacZ mice but not in the subventricular zone. High myelination levels detected at early postnatal ages (P7-P24) were an additional penetrant phenotype in Dll1 +/lacZ mice, observation that was consistent with premature oligodendrocyte differentiation. After applying a set of behavioral tests, mild neurological alterations were detected that caused changes in motor behaviors and a deficit in object categorization.
UNASSIGNED: Our observations suggest that Dll1 haploinsufficiency limits Notch signaling during brain development which, on one hand, leads to reduced brain cell density and causes microcephaly and hydrocephalus phenotypes and, on the other, alters the myelination process after birth. The severity of these defects could reach levels that affect normal brain function. Therefore, Dll1 haploinsufficiency is a risk factor that predisposes the brain to develop abnormalities with functional consequences.

The allometric scaling of the brain size and neuron number across species has been extensively studied in recent years. With the exception of primates, parrots, and songbirds, larger brains have more neurons but relatively lower neuronal densities than smaller brains. Conversely, when considering within-population variability, it has been shown that mice with larger brains do not necessarily have more neurons but rather more neurons in the brain reflect higher neuronal density. To what extent this intraspecific allometric scaling pattern of the brain applies to individuals from other species remains to be explored. Here, we investigate the allometric relationships among the sizes of the body, brain, telencephalon, cerebellum, and optic tectum, and the numbers of neurons and non-neuronal cells of the telencephalon, cerebellum, and optic tectum across 66 individuals originated from an intercross between wild and domestic chickens. Our intercross of chickens generates a population with high variation in brain size, making it an excellent model to determine the allometric scaling of the brain within population. Our results show that larger chickens have larger brains with moderately more neurons and non-neuronal cells. Yet, absolute number of neurons and non-neuronal cells correlated strongly and positively with the density of neurons and non-neuronal cells, respectively. As previously shown in mice, this scaling pattern is in stark contrast with what has been found across different species. Our findings suggest that neuronal scaling rules across species are not a simple extension of the neuronal scaling rules that apply within a species, with important implications for the evolutionary developmental origins of brain diversity.

Neuronal densities vary enormously across sites within a brain. Does the density of the capillary bed vary accompanying the presumably larger energy requirement of sites with more neurons, or with larger neurons, or is energy supply constrained by a mostly homogeneous capillary bed? Here we find evidence for the latter, with a capillary bed that represents typically between 0.7 and 1.5% of the volume of the parenchyma across various sites in the mouse brain, whereas neuronal densities vary by at least 100-fold. As a result, the ratio of capillary cells per neuron decreases uniformly with increasing neuronal density and therefore with smaller average neuronal size across sites. Thus, given the relatively constant capillary density compared to neuronal density in the brain, blood and energy availability per neuron is presumably dependent on how many neurons compete for the limited supply provided by a mostly homogeneous capillary bed. Additionally, we find that local capillary density is not correlated with local synapse densities, although there is a small but significant correlation between lower neuronal density (and therefore larger neuronal size) and more synapses per neuron within the restricted range of 6,500-9,500 across cortical sites. Further, local variations in the glial/neuron ratio are not correlated with local variations in the number of synapses per neuron or local synaptic densities. These findings suggest that it is not that larger neurons, neurons with more synapses, or even sites with more synapses demand more energy, but simply that larger neurons (in low density sites) have more energy available per cell and for the totality of its synapses than smaller neurons (in high density sites) due to competition for limited resources supplied by a capillary bed of fairly homogeneous density throughout the brain.

Autistic spectrum disorders (ASD) represent conditions starting in childhood, which are characterized by diff iculties with social interaction and communication, as well as non-typical and stereotyping models of behavior. The mechanisms and the origin of these disorders are not yet understood and thus far there is a lack of prophylactic measures for these disorders. The current study aims to estimate neuronal density in the prefrontal cortex and four hippocampal subf ields, i. e. СA1, СA2, СA3, and DG in Clstn2-KO mice as a genetic model of ASD. In addition, the level of neurogenesis was measured in the DG area of the hippocampus. This mouse strain was obtained by a knockout of the calsinthenin-2 gene (Clsnt2) in C57BL/6J mice; the latter (wild type) was used as controls. To estimate neuronal density, serial sections were prepared on a cryotome for the above-mentioned brain structures with the subsequent immunohistochemical labeling and confocal microscopy; the neuronal marker (anti-NeuN) was used as the primary antibody. In addition, neurogenesis was estimated in the DG region of the hippocampus; for this purpose, a primary antibody against doublecortin (anti-DCX) was used. In all cases Goat anti-rabbit IgG was used as the secondary antibody. The density of neurons in the CA1 region of the hippocampus was lower in Clstn2-KO mice of both sexes as compared with controls. Moreover, in males of both strains, neuronal density in this region was lower as compared to females. Besides, the differences between males and females were revealed in two other hippocampal regions. In the CA2 region, a lower density of neurons was observed in males of both strains, and in the CA3 region, a lower density of neurons was also observed in males as compared to females but only in C57BL/6J mice. No difference between the studied groups was revealed in neurogenesis, nor was it in neuronal density in the prefrontal cortex or DG hippocampal region. Our new f indings indicate that calsyntenin-2 regulates neuronal hippocampal density in subf ield-specif ic manner, suggesting that the CA1 neuronal subpopulation may represent a cellular target for early-life preventive therapy of ASD.
Расстройства аутистического спектра (РАС) – это группа состояний, возникающих в детском возрасте, для которых характерны трудности с социальным взаимодействием и общением, a также нетипичные модели поведения и склонность к стереотипии. Механизмы возникновения этой группы расстройств до сих пор не вполне понятны, и, следовательно, отсутствуют соответствующие методы профилактики. Целью исследования была оценка плотности нейронов в медиальной префронтальной коре и четырех областях гиппокампа, а именно СA1, СA2, СA3 и зубчатой извилины (DG) у мышей линии Clstn2-KO, которая может выступать в качестве генетической модели РАС. Кроме того, охарактеризовали уровень нейрогенеза в области DG гиппокампа. Данная линия получена путем нокаута гена кальсинтенина-2 (Clstn2) на основе мышей линии С57BL/6J; последняя была использована в настоящем исследовании в качестве контроля. Для определения плотности нейронов изготавливали серийные срезы соответствующих областей мозга на криотоме с последующим иммуногистохимическим окрашиванием и конфокальной микроскопией, для чего использовали нейрональный маркер (anti-NeuN) в качестве первичного антитела. Наряду с этим в области DG гиппокампа оценивали нейрогенез, для чего проводили иммуногистохимическое окрашивание с применением антитела против даблкортина (anti-DCX). В обоих случаях в качестве вторичного антитела был Goat anti-rabbit IgG. Плотность нейронов в области гиппокампа СА1 была снижена как у самцов, так и самок мышей Clstn2-KO по сравнению с контролем; у самцов обеих линий плотность нейронов была ниже в этой области по сравнению с самками. Помимо этого, были обнаружены различия между самцами и самками в двух других областях гиппокампа: в области CA2 – у мышей обеих исследованных линий, а в области CA3 лишь у мышей C57BL/6J плотность нейронов была меньше у самцов по сравнению с самками. Различий между исследованными группами в уровне нейрогенеза, а также в плотности нейронов в префронтальной коре и области DG гиппокампа не обнаружено. Полученные результаты показывают, что нокаут по гену Clstn2 приводит к избирательному снижению плотности нейронов в CA1-области гиппокампа, что может представлять собой клеточную мишень для ранней профилактики и возможной терапии РАС.

The superior colliculus (SC) is a layered midbrain structure with functions that include polysensory and sensorimotor integration. Here, we describe the distribution of different immunohistochemically identified classes of neurons in the SC of adult marmoset monkeys (Callithrix jacchus). Neuronal nuclei (NeuN) staining was used to determine the overall neuronal density in the different SC layers. In addition, we studied the distribution of neurons expressing different calcium-binding proteins (calbindin [CB], parvalbumin [PV] and calretinin [CR]). Our results indicate that neuronal density in the SC decreases from superficial to deep layers. Although the neuronal density within the same layer varies little across the mediolateral axis, it tends to be lower at rostral levels, compared to caudal levels. Cells expressing different calcium-binding proteins display differential gradients of density according to depth. Both CB- and CR-expressing neurons show markedly higher densities in the stratum griseum superficiale (SGS), compared to the stratum opticum and intermediate and deep layers. However, CR-expressing neurons are twice as common as CB-expressing neurons outside the SGS. The distribution of PV-expressing cells follows a shallow density gradient from superficial to deep layers. When normalized relative to total neuronal density, the proportion of CR-expressing neurons increases between the superficial and intermediate layers, whereas that of CB-expressing neurons declines toward the deep layers. The proportion of PV-expressing neurons remains constant across layers. Our data provide layer-specific and accurate estimates of neuronal density, which may be important for the generation of biophysical models of how the primate SC transforms sensory inputs into motor signals.

We report in a companion paper that in the mouse brain, in contrast to the 1,000-fold variation in local neuronal densities across sites, capillary density (measured both as capillary volume fraction and as density of endothelial cells) show very little variation, of the order of only fourfold. Here we confirm that finding in the rat brain and, using published rates of local blood flow and glucose use at rest, proceed to show that what small variation exists in capillary density across sites in the rat brain is strongly and linearly correlated to variations in local rates of brain metabolism at rest. Crucially, we show that such variations in local capillary density and brain metabolism are not correlated with local variations in neuronal density, which contradicts expectations that use-dependent self-organization would cause brain sites with more neurons to have higher capillary densities due to higher energetic demands. In fact, we show that the ratio of endothelial cells per neuron serves as a linear indicator of average blood flow and glucose use per neuron at rest, and both increase as neuronal density decreases across sites. In other words, because of the relatively tiny variation in capillary densities compared to the large variation in neuronal densities, the anatomical infrastructure of the brain is such that those sites with fewer neurons have more energy supplied per neuron, which matches a higher average rate of energy use per neuron, compared to sites with more neurons. Taken together, our data support the interpretation that resting brain metabolism is not demand-based, but rather limited by its capillary supply, and raise multiple implications for the differential vulnerability of diverse brain areas to disease and aging.

Alzheimer\'s disease (AD) is a progressive neurodegenerative disorder with neuronal loss in the hippocampus. Our aim was to evaluate the effects of Iranian thyme honey (single dose: 2 gr/kg) vs rivastigmine (0.3 mg/kg) in vivo on spatial memory and in vitro on important parameters of oxidative stress as well as quantitative and qualitative studies of hippocampal neurons of AD rat models with this design that 30 days after oral administration of 17 mg/kg AlCl3, 20 AD rats were received that underwent a 6-weeks therapeutic period and another 20 rats underwent a 6-weeks preventive period and also 20 rats were as controls. Y-Maze test was performed to show memory deficiency as well as TBARS and FRAP assays to measure malondialdehyde (MDA) and total antioxidant, respectively. In addition, H&E staining was also done for cell counting and morphological changes. We observed that AD rats with hippocampal damage had more significant errors during the Y-maze test than the control and other rats. Likewise, MDA and neurodegeneration increased in the AD group while in all preventive and therapeutic group\'s especially Iranian thyme honey, they decreased and conversely, total antioxidant and number of normal cells elevated and healthy neurons were observed in all parts of the hippocampus and cortex. Our results despite the limitations showed the powerful antioxidant properties and cytoprotective effects of Iranian thyme honey vs rivastigmine on hippocampal neurons that consequently enhanced memory and if advanced diagnostic tests in human clinical patients show other more pronounced effects, we have certainly started a key and targeted strategy.

The present study aimed to evaluate the effects of Apelin-13 on scopolamine-induced memory impairment in rats. Forty male rats were divided into five groups of eight. The control group received no intervention; the scopolamine group underwent stereotaxic surgery and received 3 mg/kg intraperitoneal scopolamine. The treatment groups additionally received 1.25, 2.5 and 5 µg apelin-13 in right lateral ventricles for 7 days. All rats (except the control group) were tested for the passive avoidance reaction, 24 h after the last drug injection. For histological analysis, hippocampal sections were stained with cresyl violet; synaptogenesis biochemical markers were determined by immunoblotting. Apelin-13 alleviated scopolamine-induced passive avoidance memory impairment and neuronal loss in the rats\' hippocampus (P<0.001). The reduction observed in mean concentrations of hippocampal synaptic proteins (including neurexin1, neuroligin, and postsynaptic density protein 95) in scopolamine-treated animals was attenuated by apelin-13 treatment. The results demonstrated that apelin-13 can protect against passive avoidance memory deficiency, and neuronal loss, induced by scopolamine in male rats. Further experimental and clinical studies are required to confirm its therapeutic potential in neurodegenerative diseases.