Tracking changes in functionality and morphology of repopulated microglia in young and old mice.

Background: Microglia (MG) are myeloid cells of the central nervous system that support homeostasis and instigate neuroinflammation in pathologies. Single-cell RNA sequencing (scRNA-seq) revealed the functional heterogeneity of MG in mouse brains. Microglia are self-renewing cells and inhibition of colony-stimulating factor 1 receptor (CSF1R) signaling depletes microglia which rapidly repopulate.

Melanotan-II reverses memory impairment induced by a short-term HF diet.

A high-fat (HF) diet has been shown to increase the risk of neurological impairments and neurodegenerative disorders. The melanotropins used in this study have been associated with diet-related disorders; however, there is an absence of studies on their effect on diet-induced neurobehavioral conditions. Here, we investigated the possible relationship among diet, Melanotan-II (MT-II) targeting melanotropin receptors, and the behavior of zebrafish (Danio rerio).

Behavioral characteristics as potential biomarkers of the development and phenotype of epilepsy in a rat model of temporal lobe epilepsy.

The present study performed a detailed analysis of behavior in a rat model of epilepsy using both established and novel methodologies to identify behavioral impairments that may differentiate between animals with a short versus long latency to spontaneous seizures and animals with a low versus high number of seizures. Temporal lobe epilepsy was induced by electrical stimulation of the amygdala. Rats were stimulated for 25 min with 100-ms trains of 1-ms biphasic square-wave pluses that were delivered every 0.

IntelliCage as a tool for measuring mouse behavior - 20 years perspective.

Since the 1980s, we have witnessed the rapid development of genetically modified mouse models of human diseases. A large number of transgenic and knockout mice have been utilized in basic and applied research, including models of neurodegenerative and neuropsychiatric disorders. To assess the biological function of mutated genes, modern techniques are critical to detect changes in behavioral phenotypes.

Reward learning requires activity of matrix metalloproteinase-9 in the central amygdala.

Learning how to avoid danger and pursue reward depends on negative emotions motivating aversive learning and positive emotions motivating appetitive learning. The amygdala is a key component of the brain emotional system; however, an understanding of how various emotions are differentially processed in the amygdala has yet to be achieved. We report that matrix metalloproteinase-9 (MMP-9, extracellularly operating enzyme) in the central nucleus of the amygdala (CeA) is crucial for appetitive, but not for aversive, learning in mice.

Cognitive abilities of Alzheimer's disease transgenic mice are modulated by social context and circadian rhythm.

In the present study, we used a new training paradigm in the intelliCage automatic behavioral assessment system to investigate cognitive functions of the transgenic mice harboring London mutation of the human amyloid precursor protein (APP.V717I). Three groups of animals: 5-, 12- and 18-24-month old were subjected to both Water Maze training and the IntelliCage-based appetitive conditioning.

Transient brain ischemia due to cardiac arrest causes irreversible long-lasting cognitive injury.

Herein, we used a clinically-relevant model of 10 min cardiac arrest (CA) in Wistar rats. Histological analyses of the ischemic brains of old rats showed significant atrophy of CA(1) sector of hippocampus (Nissl and NeuN stainings) corresponding with increase of glial fibrillary acidic protein expression. The long-term behavioral consequences of above manipulation producing global brain ischemia were assessed in young, middle-aged and old rats, i.

MicroRNA loss enhances learning and memory in mice.

Dicer-dependent noncoding RNAs, including microRNAs (miRNAs), play an important role in a modulation of translation of mRNA transcripts necessary for differentiation in many cell types. In vivo experiments using cell type-specific Dicer1 gene inactivation in neurons showed its essential role for neuronal development and survival. However, little is known about the consequences of a loss of miRNAs in adult, fully differentiated neurons.

New hippocampal neurons are not obligatory for memory formation; cyclin D2 knockout mice with no adult brain neurogenesis show learning.

The role of adult brain neurogenesis (generating new neurons) in learning and memory appears to be quite firmly established in spite of some criticism and lack of understanding of what the new neurons serve the brain for. Also, the few experiments showing that blocking adult neurogenesis causes learning deficits used irradiation and various drugs known for their side effects and the results obtained vary greatly. We used a novel approach, cyclin D2 knockout mice (D2 KO mice), specifically lacking adult brain neurogenesis to verify its importance in learning and memory.

Behavioral characterization of GLT1 (+/-) mice as a model of mild glutamatergic hyperfunction.

GLT1 is one of the major transporters responsible for maintenance of glutamate homeostasis in the brain. In the present study, glutamate transporter 1-deficient GLT1 homozygous (-/-) and heterozygous (+/-) mice were investigated with the intention that they may provide a model of hyperglutamatergic state resulting in various behavioral alterations. The GLT1 (-/-) mice had lower body and brain weight, mild neuronal loss in CA1 hippocampal region as well as focal gliosis and severe focal neuronal paucity in layer II of the neocortex.

Genetic models to study adult neurogenesis.

In the central nervous system (CNS) generation of new neurons continues throughout adulthood, when it is limited to the olfactory bulb and hippocampus. The knowledge regarding the function of newly-generated neurons remains limited and is vigorously investigated using diverse approaches. Among these are genetically modified mice, most of them of knock-out type (KO).