Результаты поиска

Prenatal alcohol exposure induces long-term changes in dendritic spines and synapses in the mouse visual cortex.

AIMS: To study the long-term changes of dendritic spine and synapse taking place in a mouse model of fetal alcohol spectrum disorders (FASDs). METHODS: Pregnant mice were intubated daily with ethanol (EtOH) from E5 to parturition. A DiI diolistic method was used to label dendritic spines of pyramidal cells in the visual cortex of EtOH-exposed and control pups over the period from postnatal (P) day P0 to P30; synaptic ultrastructure was also analyzed using transmission electron microscopy. RESULTS: Prenatal alcohol exposure was associated with a significant decrease in the number of dendritic…

Cocaine self-administration alters the morphology of dendrites and dendritic spines in the nucleus accumbens and neocortex.

We studied the influence of cocaine use on the structure of neurons in brain regions that contribute to its rewarding effects by allowing rats to self-administer cocaine (0.33 mg/infusion) for 1 h a day for 1 month. Control animals were left undisturbed or allowed to work for food for the same period of time. After an additional 1 month drug-free period the brains were processed for Golgi-Cox staining. In rats that self-administered cocaine, but not rats that worked for food, there was a significant increase in dendritic branching and in the density of dendritic spines on medium spiny neurons …

Dendritic spine plasticity and chronic alcoholism in rats.

Alcohol consumption in rats leads to degenerative changes in the cerebellar cortex (described elsewhere). Purkinje cells show a loss of dendritic spines, but some of the intact spines elongate to 3-4 times their normal length. This is postulated as a plastic change resulting from the degeneration of the original axon terminal contact with a consequent elongation of the spine 'in search of' and finally synapsing with still viable parallel fibre terminals in the vicinity. Under these conditions the circuitry is radically altered.

The Role of Dendritic Spines in Water Exchange Measurements With Diffusion MRI: Time-Dependent Single Diffusion Encoding MRI.

Time-dependent diffusion MRI (dMRI) using single diffusion encoding (SDE) is sensitive to water dynamics in biological tissues, yet interpre … han specific spine morphology. Simulations reveal that unaccounted diffusion-mediated exchange from dendritic spines substantially biases Neurite Exchange Imaging (NEXI) estimates, inflating the apparent exchange rate and the inferred membrane permeability in proportion to spine volume fraction. Further, we propose an extended three-compartment Kärger model (and i …

Microglia interact with dendritic spines and regulate spine numbers after brain injury following resuscitation from a cardiac arrest.

Cognitive dysfunction is common after global cerebral ischemic injury caused by a cardiac arrest and is likely due in part to changes in synaptic function. Increasing evidence suggests microglial cells regulate synapse architecture and activity in various pathophysiologic conditions. However, the role of microglia in mediating synaptic injury after global cerebral ischemia has not been addressed. In this study, we use a mouse model of cardiac arrest and cardiopulmonary resuscitation (CA/CPR) to evaluate changes that occur in the numbers and morphology of both dendritic spines and microglia in …

TAF15 downregulation contributes to the benefits of physical training on dendritic spines and working memory in aged mice.

Moderate physical training has been shown to hinder age-related memory decline. While the benefits of physical training on hippocampal memor … itic branches. Correlation analysis revealed that increased TAF15-expression was detrimental to the dendritic spines. However, physical training downregulated TAF15 expression in the PrL, preserving the dendritic spines on PrL pyramidal cells and improving working memory in trained aged mice. When TAF15 was overexpressed in the PrL via a viral approach, the benefi …

Extinction procedure induces pruning of dendritic spines in CA1 hippocampal field depending on strength of training in rats.

Numerous reports indicate that learning and memory of conditioned responses are accompanied by genesis of dendritic spines in the hippocampus, although there is a conspicuous lack of information regarding spine modifications after behavioral extinction. There is ample evidence that treatments that typically produce amnesia become innocuous when animals are submitted to a procedure of enhanced training. We now report that extinction of inhibitory avoidance (IA), trained with relatively low foot-shock intensities, induces pruning of dendritic spines along the length of the apical dendrites of hi…

3D dendritic spines shape descriptors for efficient classification and morphology analysis in control and Alzheimer's disease modeling neurons.

MOTIVATION: Dendritic spines, postsynaptic structures characterized by their complex shapes, provide the essential structural foundation for synaptic function. Their shape is dynamic, undergoing alterations in various conditions, notably during neurodegenerative disorders like Alzheimer's disease. The dramatically increasing prevalence of such diseases highlights an urgent need for effective treatments. A key strategy in developing these treatments involves evaluating how dendritic spine morphology responds to potential therapeutic compounds. Although a link between spine shape and function is…

Cognitive integrity in Non-Demented Individuals with Alzheimer's Neuropathology is associated with preservation and remodeling of dendritic spines.

INTRODUCTION: Individuals referred to as Non-Demented with Alzheimer's Neuropathology (NDAN) exhibit cognitive resilience despite presenting Alzheimer's disease (AD) histopathological signs. Investigating the mechanisms behind this resilience may unveil crucial insights into AD resistance. METHODS: DiI labeling technique was used to analyze dendritic spine morphology in control (CTRL), AD, and NDAN post mortem frontal cortex, particularly focusing on spine types near and far from amyloid beta (Aβ) plaques. RESULTS: NDAN subjects displayed a higher spine density in regions distant from Aβ pla

Independent APOE4 knock-in mouse models display reduced brain APOE protein, altered neuroinflammation, and simplification of dendritic spines.

APOE is an immunomodulator in the brain and the major genetic risk factor for late-onset Alzheimer's disease (AD). Targeted replacement APOE mice (APOE-TR) have been a useful tool to study the effects of APOE isoforms on brain neurochemistry and activity prior to and during AD. We use newly available APOE knock-in mice (JAX-APOE) to compare phenotypes associated with APOE4 across models. Similar to APOE4-TR mice, JAX-E4 mouse brains showed 27% lower levels of APOE protein compared with JAX-E3 (p < 0.001). We analyzed several neuroinflammatory molecules that have been associated with APOE genot

Angiotensin Type 2 Receptor Pharmacological Agonist Relieves Neurocognitive Deficits via Reducing Neuroinflammation and Microglial Engulfment of Dendritic Spines.

Mechanically ventilated patients suffering critical illness are at high risk of developing neurocognitive impairments. Angiotensin type 2 receptor (AGTR2) has been demonstrated to be anti-inflammatory and neuroprotective. The present study thus aimed to investigate whether AGTR2 can alleviate cerebral dysfunction in mice subjected to cochallenge with lipopolysaccharide (LPS) and mechanical ventilation (MV), and to reveal the underlying mechanism. We utilized a mice model that received a single injection of LPS (1 mg/kg, intraperitoneally) followed 2 h later by MV (10 ml/kg, lasting for 2 h). P

In Vivo Study of Dynamics and Stability of Dendritic Spines on Olfactory Bulb Interneurons in Xenopus laevis Tadpoles.

Dendritic spines undergo continuous remodeling during development of the nervous system. Their stability is essential for maintaining a functional neuronal circuit. Spine dynamics and stability of cortical excitatory pyramidal neurons have been explored extensively in mammalian animal models. However, little is known about spiny interneurons in non-mammalian vertebrate models. In the present study, neuronal morphology was visualized by single-cell electroporation. Spiny neurons were surveyed in the Xenopus tadpole brain and observed to be widely distributed in the olfactory bulb and telencepha…

DPP-4 inhibitor and PPARγ agonist restore the loss of CA1 dendritic spines in obese insulin-resistant rats.

BACKGROUND AND AIMS: Obesity induced by high-fat diet (HFD) impaired brain insulin receptor function, caused cognitive decline as well as reduced dendritic spine density. Previous studies suggested that dipeptidyl peptidase IV (DPP-4) inhibitor and peroxisome proliferator-activated receptor-gamma (PPARγ) agonist exerted the neuroprotective effects in obese insulin-resistant rats. However, the effects of these drugs on dendritic spines in obese insulin-resistant rats have not yet been investigated. In the present study, we determined the effects of DPP-4 inhibitor and PPARγ agonist on dendritic…

The Rac1-GEF Tiam1 couples the NMDA receptor to the activity-dependent development of dendritic arbors and spines.

NMDA-type glutamate receptors play a critical role in the activity-dependent development and structural remodeling of dendritic arbors and spines. However, the molecular mechanisms that link NMDA receptor activation to changes in dendritic morphology remain unclear. We report that the Rac1-GEF Tiam1 is present in dendrites and spines and is required for their development. Tiam1 interacts with the NMDA receptor and is phosphorylated in a calcium-dependent manner in response to NMDA receptor stimulation. Blockade of Tiam1 function with RNAi and dominant interfering mutants of Tiam1 suggests that

Decreased numbers of dendritic spines on cortical pyramidal neurons in dementia. A quantitative Golgi study on biopsy samples.

The number of dendritic spines on the apical dendrites of layer III pyramidal cells was counted in cerebral biopsies, processed in part according to the rapid Golgi method, which had been performed for diagnostic purposes on patients suffering from dementia of different origins. The samples were from cases affected by Alzheimer's disease (3 patients), Parkinson's disease and dementia (1 patient), Creutzfeldt-Jacob disease (4 patients), Pick's disease (1 patient) and dementia paralytica (1 patient). Spines were counted on consecutive segments of the apical dendrite along the 500-microns proxima…

Brainstem immaturity in sudden infant death syndrome: a quantitative rapid Golgi study of dendritic spines in 95 infants.

Quantitative analysis of reticular dendritic spines was performed on rapid Golgi impregnated neurons in 7 brainstem areas from 61 sudden infant death syndrome (SIDS) and 34 control infants. Throughout the first postnatal year, mean spine density in SIDS was significantly greater than the mean density in controls (P less than 0.0001). There were significantly higher values of spine density in SIDS compared to controls (P less than 0.0001) in both term and preterm infants. Within the SIDS brainstem itself, the density of dendritic spines was significantly different (P less than 0.05) between two…

Effects of the antipsychotics haloperidol, clozapine, and aripiprazole on the dendritic spine.

Three types of antipsychotics, typical (e.g. haloperidol), atypical (e.g. clozapine), and dopamine partial agonist (e.g. aripiprazole), are … cade. Selection and appropriate dose of these antipsychotics may be important for the protection of dendritic spines in patients with schizophrenia.

Dendritic spine formation and pruning: common cellular mechanisms?

The recent advent of novel high-resolution imaging methods has created a flurry of exciting observations that address a century-old question: what are biological signals that regulate formation and elimination of dendritic spines? Contrary to the traditional belief that the spine is a stable storage site of long-term neuronal memory, the emerging picture is of a dynamic structure that can undergo fast morphological variations. Recent conflicting reports on the regulation of spine morphology lead to the proposal of a unifying hypothesis for a common mechanism involving changes in postsynaptic i…

Effect of tibolone on dendritic spine density in the rat hippocampus.

INTRODUCTION: Oestrogen deficiency produces oxidative stress (OS) and changes in hippocampal neurons and also reduces the density of dendritic spines (DS). These alterations affect the plastic response of the hippocampus. Oestrogen replacement therapy reverses these effects, but it remains to be seen whether the same changes are produced by tibolone (TB). The aim of this study was to test the neuroprotective effects of long-term oral TB treatment and its ability to reverse DS pruning in pyramidal neurons (PN) of hippocampal area CA1. METHODS: Young Sprague Dawley rats were distributed in 3 gr…

Дендритическая патология позвоночника: причина или следствие неврологических расстройств?

Измененные дендритические позвоночники характерны для травмированного или больного мозга. Можно выделить две общие категории патологии позвоночника: патологии распределения и патологии ультраструктуры. Патологии распределения позвоночника влияют на многие позвоночники вдоль дендритов нейрона и включают изменяющиеся числа позвоночника, искаженные формы позвоночника и аномальные локси происхождения позвоночника на нейроне. Патологии ультраструктуры позвоночника связаны с деформацией подклеточных органелл внутри дендритических позвоночников. Распределение шпильки изменяется на зрелых нейронах пос

Совпадение в аннотации оригинала
Altered dendritic spines are characteristic of traumatized or diseased brain. Two general categories of spine pathology can be distinguished: pathologies of distribution and pathologies of ultrastructure. Pathologies of spine distribution affect many spines along the dendrites of a neuron and include altered spine numbers, distorted spine shapes, and abnorma…