After a spatial behavioral experience, hippocampal CA1 pyramidal cells express the activity-regulated, immediate early gene Arc in an environment-specific manner, and similar proportions (˜40%) to exhibiting electrophysiologically recorded place fields under conditions. Theoretical accounts of function fascia dentata suggest that it plays role pattern separation during encoding. The hypothesis dentate gyrus (DG) uses sparse, thus more orthogonal, coding scheme has been supported by...

The immediate-early gene Arc is transcribed in neurons that are part of stable neural networks activated during spatial exploratory behaviors. protein has been demonstrated to regulate AMPA-type glutamate receptor trafficking by recruiting endosomal pathways, suggesting a direct role synaptic plasticity. purpose the present study examine fidelity mRNA translation and temporal dynamics behaviorally induced expression after rats explore novel environment. These experiments reveal two waves...

Although it is established that new granule cells can be born and survive in the adult mammalian hippocampus, there remains some question concerning functional integration of these neurons into behaviorally relevant neural networks. By using high-resolution confocal microscopy, we have applied a strategy to address newborn networks mediate spatial information processing memory formation. Exploration-induced expression immediate-early gene Arc hippocampal has been linked cellular activity...

Abstract Active behavior, such as exploring a novel environment, induces the expression of immediate‐early gene Arc ( ctivity‐ r egulated c ytoskeletal associated protein, or Arg 3.1) in many brain regions, including hippocampus, neocortex, and striatum. messenger ribonucleic acid protein are localized activated dendrites, is required for maintenance long‐term potentiation memory consolidation. Although previous evidence suggests that expressed neurons, there no direct demonstration only...

Structural synaptic changes have been suggested to underlie long-term memory formation. In this work, we investigate if hippocampal mossy fiber synaptogenesis induced by water maze overtraining can be related with spatial performance. Rats were trained in a Morris for one five identical daily sessions and tested retrieval 1 week month after training. After the last test session, rat brains obtained processed Timm9s staining analyze projection. The behavioral results showed that more...

Neuroinflammation is associated with a variety of neurological and pathological diseases, such as Alzheimer's disease (AD), reliably detected by the presence activated microglia. In early AD, highest degree microglia observed in brain regions involved learning memory. To investigate whether neuroinflammation alters pattern rapid de novo gene expression memory, we studied activity-induced immediate Arc hippocampus rats experimental neuroinflammation. Rats were chronically infused...

Glucocorticoids and corticotropin-releasing hormone (CRH) are key regulators of stress responses. Different types activate the CRH system; in hypothalamus, expression release increased by physical or psychological stressors while amygdala, preferentially stress. Learning memory processes modulated glucocorticoids at different levels. To characterize kind provoked a hippocampal-dependent task such as spatial learning, we compared profile glucocorticoid receptor (GR), pro-CRH CRH-R1 mRNAs...

Understanding how the hippocampus processes episodic memory information during neuropathological conditions is important for treatment and prevention applications. Previous data have shown that chronic neuroinflammation expression of plasticity related behaviourally-induced immediate early gene Arc altered within CA3 dentate gyrus; both these hippocampal regions show a pronounced increase in activated microglia. Low doses memantine, low to moderate affinity open channel uncompetitive...

After spatial exploration in rats, Arc mRNA is expressed ∼2% of dentate gyrus (DG) granule cells, and this proportion Arc-positive neurons remains stable for ∼8 h. This long-term presence following behavior not observed hippocampal CA1 pyramidal cells. We report here that rats ∼50% cells with cytoplasmic mRNA, induced some hours previously during exploration, also show expression the nucleus. suggests recent transcription can occur long after elicited it. To confirm delayed nuclear was...

Neuroinflammation plays a prominent role in the progression of Alzheimer's disease and may be responsible for degeneration vulnerable regions such as hippocampus. is associated with elevated levels extracellular glutamate potentially an enhanced stimulation N-methyl-D-aspartate receptors. This suggests that neurons express these receptors might at increased risk presence chronic neuroinflammation. We have characterized novel model brain inflammation using slow infusion lipopolysaccharide...

Adult-born neurons in the dentate gyrus (DG) functionally integrate into behaviorally relevant hippocampal networks, showing a specific Arc-expression response to spatial exploration when mature. However, it is not clear when, during 4- 6-week interval that critical for survival and maturation of these neurons, this develops. Therefore, we characterized Arc expression after or cage control conditions adult-born from rats were injected with BrdU on one day sacrificed 1, 7, 15, 30, 45 days...

Abstract Adult‐born neurons in the dentate gyrus (DG) can survive for long periods, are capable of integrating into neuronal networks, and important hippocampus‐dependent learning. Neurogenesis is dramatically reduced during senescence, it remains unknown whether those few that produced remain network integration. The expression Arc, a protein coupled to activity, was used measure activity among granule cells were labeled with BrdU 4 months earlier young (9 months) aged (25 Fischer344 rats....

Ageing displays a low-grade pro-inflammatory profile in blood and the brain. Accumulation of cytokines, microglia activation volumetric changes brain correlate with cognitive decline ageing models. However, interplay between them is not totally understood. Here, we aimed to globally identify an age-dependent morphological plasticity that favors major volume associated decline. Cluster analysis behavioral data obtained from 2-,12- 20-month-old male C57BL/6 mice revealed after Y-maze, Barnes...

Decades of research identify the hippocampal formation as central to memory storage and recall. Events are stored via distributed population codes, parameters which (e.g., sparsity overlap) determine both capacity fidelity. However, it remains unclear whether governing information similar between species. Because episodic memories rooted in space they experienced, response navigation is often used a proxy study memory. Critically, recent studies rodents that mimic conditions typical humans...