ABSTRACT
For decades, memory research has centered on the role of neurons, which do not function in isolation. However, astrocytes play important roles in regulating neuronal recruitment and function at the local and network levels, forming the basis for information processing as well as memory formation and storage. In this review, we discuss the role of astrocytes in memory functions and their cellular underpinnings at multiple time points. We summarize important breakthroughs and controversies in the field as well as potential avenues to further illuminate the role of astrocytes in memory processes.
Subject(s)
Astrocytes , Neuronal Plasticity/physiology , Memory/physiology , Neurons/physiology , Cognition/physiologyABSTRACT
Food deprivation can rescue obesity and overweight-induced mood disorders, and promote mood performance in normal subjects. Animal studies and clinical research have revealed the antidepressant-like effect of calorie restriction, but little is known about the mechanism of calorie restriction-induced mood modification. Previous studies have found that astrocytes modulate depressive-like behaviors. Inositol 1,4,5-trisphosphate receptor type 2 (IP3R2) is the predominant isoform in mediating astrocyte Ca
ABSTRACT
Food deprivation can rescue obesity and overweight-induced mood disorders, and promote mood performance in normal subjects. Animal studies and clinical research have revealed the antidepressant-like effect of calorie restriction, but little is known about the mechanism of calorie restriction-induced mood modification. Previous studies have found that astrocytes modulate depressive-like behaviors. Inositol 1,4,5-trisphosphate receptor type 2 (IP3R2) is the predominant isoform in mediating astrocyte Ca
Subject(s)
Animals , Mice , Adenosine Triphosphate , Antidepressive Agents/therapeutic use , Caloric Restriction , Mice, Knockout , Prefrontal CortexABSTRACT
Astrocytes are the most abundant cell type in the central nervous system (CNS). They provide trophic support for neurons, modulate synaptic transmission and plasticity, and contribute to neuronal dysfunction. Many transgenic mouse lines have been generated to obtain astrocyte-specific expression of inducible Cre recombinase for functional studies; however, the expression patterns of inducible Cre recombinase in these lines have not been systematically characterized. We generated a new astrocyte-specific Aldh1l1-CreER knock-in mouse line and compared the expression pattern of Cre recombinase between this and five widely-used transgenic lines (hGfap-CreER from The Jackson Laboratory and The Mutant Mouse Resource and Research Center, Glast-CreER, Cx30-CreER, and Fgfr3-iCreER) by crossing with Ai14 mice, which express tdTomato fluorescence following Cre-mediated recombination. In adult Aldh1l1-CreER:Ai14 transgenic mice, tdTomato was detected throughout the CNS, and five novel morphologically-defined types of astrocyte were described. Among the six evaluated lines, the specificity of Cre-mediated recombination was highest when driven by Aldh1l1 and lowest when driven by hGfap; in the latter mice, co-staining between tdTomato and NeuN was observed in the hippocampus and cortex. Notably, evident leakage was noted in Fgfr3-iCreER mice, and the expression level of tdTomato was low in the thalamus when Cre recombinase expression was driven by Glast and in the capsular part of the central amygdaloid nucleus when driven by Cx30. Furthermore, tdTomato was clearly expressed in peripheral organs in four of the lines. Our results emphasize that the astrocyte-specific CreER transgenic lines used in functional studies should be carefully selected.
ABSTRACT
Major depressive disorder (MDD) is a common mood disorder that affects almost 20% of the global population. In addition, much evidence has implicated altered function of the gamma-aminobutyric acid (GABAergic) system in the pathophysiology of depression. Recent research has indicated that GABA receptors (GABARs) are an emerging therapeutic target in the treatment of stress-related disorders such as MDD. However, which cell types with GABARs are involved in this process is unknown. As hippocampal dysfunction is implicated in MDD, we knocked down GABARs in the hippocampus and found that knocking down these receptors in astrocytes, but not in GABAergic or pyramidal neurons, caused a decrease in immobility in the forced swimming test (FST) without affecting other anxiety- and depression-related behaviors. We also generated astrocyte-specific GABAR-knockout mice and found decreased immobility in the FST in these mice. Furthermore, the conditional knockout of GABARs in astrocytes selectively increased the levels of brain-derived neurotrophic factor protein in hippocampal astrocytes, which controlled the decrease in immobility in the FST. Taken together, our findings contribute to the current understanding of which cell types expressing GABARs modulate antidepressant activity in the FST, and they may provide new insights into the pathological mechanisms and potential targets for the treatment of depression.
ABSTRACT
<p><b>OBJECTIVE</b>To determine the effects of Jiji decoction (Traditional Chinese Medicine) on the cognitive function and oxidative stress in mice with vascular dementia (VD) induced by cerebral ischemia/reperfusion.</p><p><b>METHODS</b>Thirty-two mice were randomly divided into nonnal group (n = 8), sham group (operation, but no cerebral ischemia/reperfusi6n, n = 8), model group (vascular dementia model induced by cerebral ischemia/reperfusion, n = 8), and Jiji decoction-treated group (vascular dementia model plus treatment with Jiji decoction, n = 8). Fourteen days of treatment after operation, the cognitive behavior was measured in step-through test, spatial probe test and platform test. Afterwards, to assess the levels of oxidative stress, the activity of superoxide dismutase(SOD) and content of malonaldehyde (MDA) in brain of these mice were measured.</p><p><b>RESULTS</b>Data from step-through test indicated that the escaping latency of Jiji decoction-treated group was prolonged and the error counts were decreased significantly ( P <0.01) compared with those of model group. Data from spatial probe test indicated that the time of entering darkroom, the time of climbing height and the time of entering bright room in Jiji decoction-treated group were shortened and the counts of climbing height were increased (P < 0.05-0.01) significantly compared with those of model group. Data from platform test showed that the escaping latency of Jiji decoction-treated group was prolonged significantly (P < 0.01) compared with that of model group. Compared with normal and sham group, the activity of SOD was decreased and the content of MDA was increased in model group significantly (P < 0.01). Compared with those of model group, the levels of SOD and MDA in Jiji decoction-treated group were improved significantly (P < 0.01).</p><p><b>CONCLUSION</b>Jiji decoction could improve cognitive function of VD mice. Its mechanism might be related with the inhibition of oxidative stiess in the brain.</p>
Subject(s)
Animals , Mice , Brain , Metabolism , Cerebral Infarction , Cognition , Dementia, Vascular , Drug Therapy , Drugs, Chinese Herbal , Pharmacology , Malondialdehyde , Metabolism , Medicine, Chinese Traditional , Oxidative Stress , Reperfusion Injury , Drug Therapy , Superoxide Dismutase , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To observe the effect of fibrous capsule to prevent the flexor tendon adhesion.</p><p><b>METHODS</b>Six bum patients with 33 digits were treated with the fibrous capsule of the expanded flaps which was used to wrap the exposed flexor tendon in zone III in order to prevent the flexor tendon adhesion.</p><p><b>RESULTS</b>From 1999-2001 ,all of the patients were followed up to 1-3 years. The functions, assessed with the TAM method, were excellent in 18 digits, fair in three and poor in one. The excellent and good rate was 87.88%.</p><p><b>CONCLUSION</b>The fibrous capsule could be used to prevent or reduce the tendon adhesion.</p>
Subject(s)
Adult , Female , Humans , Male , Burns , Rehabilitation , General Surgery , Head , Physiology , General Surgery , Muscles , General Surgery , Surgical Flaps , Surgical Procedures, Operative , Methods , Tendons , General Surgery , Tissue Adhesions , Treatment OutcomeABSTRACT
An improved method is described for fast and reliable isolation of neurons from hippocampus of adult rats by a combination of mechanical and enzymatic means. The procedure allows the isolation of neurons from 500-600-d-old rats (over 300 g), preserving the proximal dendritic structure without impairing the electrical characteristics of the cells. Morphologically distinct neurons can be recognized. Using cell-attached, inside-out and whole-cell configurations of patch clamp technique, it was shown that the enzymatically isolated neurons in hippocampus from rats weighing more than 300 g exhibited voltage-gated calcium, sodium and potassium currents, outwardly rectifying chloride channel and large conductance Ca(2+)-activated potassium channel currents. Approximately, 95% of healthy cells allowed the formation of giga-ohm seals.