ABSTRACT
Astrocytes are the largest glial population in the mammalian brain. However, we have a minimal understanding of astrocyte development, especially fate specification in different regions of the brain. Through lineage tracing of the progenitors of the third ventricle (3V) wall via in-utero electroporation in the embryonic mouse brain, we show the fate specification and migration pattern of astrocytes derived from radial glia along the 3V wall. Unexpectedly, radial glia located in different regions along the 3V wall of the diencephalon produce distinct cell types: radial glia in the upper region produce astrocytes and those in the lower region produce neurons in the diencephalon. With genetic fate mapping analysis, we reveal that the first population of astrocytes appears along the zona incerta in the diencephalon. Astrogenesis occurs at an early time point in the dorsal region relative to that in the ventral region of the developing diencephalon. With transcriptomic analysis of the region-specific 3V wall and lateral ventricle (LV) wall, we identified cohorts of differentially-expressed genes in the dorsal 3V wall compared to the ventral 3V wall and LV wall that may regulate astrogenesis in the dorsal diencephalon. Together, these results demonstrate that the generation of astrocytes shows a spatiotemporal pattern in the developing mouse diencephalon.
Subject(s)
Mice , Animals , Astrocytes , Neuroglia/physiology , Diencephalon , Brain , Neurons , MammalsABSTRACT
cFos is one of the most widely-studied genes in the field of neuroscience. Currently, there is no systematic database focusing on cFos in neuroscience. We developed a curated database-cFos-ANAB-a cFos-based web tool for exploring activated neurons and associated behaviors in rats and mice, comprising 398 brain nuclei and sub-nuclei, and five associated behaviors: pain, fear, feeding, aggression, and sexual behavior. Direct relationships among behaviors and nuclei (even cell types) under specific stimulating conditions were constructed based on cFos expression profiles extracted from original publications. Moreover, overlapping nuclei and sub-nuclei with potentially complex functions among different associated behaviors were emphasized, leading to results serving as important clues to the development of valid hypotheses for exploring as yet unknown circuits. Using the analysis function of cFos-ANAB, multi-layered pictures of networks and their relationships can quickly be explored depending on users' purposes. These features provide a useful tool and good reference for early exploration in neuroscience. The cFos-ANAB database is available at www.cfos-db.net .
Subject(s)
Animals , Mice , Rats , Fear , Neurons , Proto-Oncogene Proteins c-fosABSTRACT
cFos is one of the most widely-studied genes in the field of neuroscience. Currently, there is no systematic database focusing on cFos in neuroscience. We developed a curated database—cFos-ANAB—a cFos-based web tool for exploring activated neurons and associated behaviors in rats and mice, comprising 398 brain nuclei and sub-nuclei, and five associated behaviors: pain, fear, feeding, aggression, and sexual behavior. Direct relationships among behaviors and nuclei (even cell types) under specific stimulating conditions were constructed based on cFos expression profiles extracted from original publications. Moreover, overlapping nuclei and sub-nuclei with potentially complex functions among different associated behaviors were emphasized, leading to results serving as important clues to the development of valid hypotheses for exploring as yet unknown circuits. Using the analysis function of cFos-ANAB, multi-layered pictures of networks and their relationships can quickly be explored depending on users’ purposes. These features provide a useful tool and good reference for early exploration in neuroscience. The cFos-ANAB database is available at www.cfos-db.net.
ABSTRACT
Social defeat stress (SDS) plays a major role in the pathogenesis of psychiatric disorders like anxiety and depression. Sleep is generally considered to involve recovery of the brain from prior experience during wakefulness and is altered after acute SDS. However, the effect of acute SDS on sleep/wake behavior in mice varies between studies. In addition, whether sleep changes in response to stress contribute to anxiety is not well established. Here, we first investigated the effects of acute SDS on sleep/wake states in the active period in mice. Our results showed that total sleep time (time in rapid eye-movement [REM] and non-REM [NREM] sleep) increased in the active period after acute SDS. NREM sleep increased mainly during the first 3 h after SDS, while REM sleep increased at a later time. Then, we demonstrated that the increased NREM sleep had an anxiolytic benefit in acute SDS. Mice deprived of sleep for 1 h or 3 h after acute SDS remained in a highly anxious state, while in mice with ad libitum sleep the anxiety rapidly faded away. Altogether, our findings suggest an anxiolytic effect of NREM sleep, and indicate a potential therapeutic strategy for anxiety.
ABSTRACT
The main lysosomal protease cathepsin D (cathD) is essential for maintaining tissue homeostasis via its degradative function, and its loss leads to ceroid accumulation in the mammalian nervous system, which results in progressive neurodegeneration. Increasing evidence implies non-proteolytic roles of cathD in regulating various biological processes such as apoptosis, cell proliferation, and migration. Along these lines, we here showed that cathD is required for modulating dendritic architecture in the nervous system independent of its traditional degradative function. Upon cathD depletion, class I and class III arborization (da) neurons in Drosophila larvae exhibited aberrant dendritic morphology, including over-branching, aberrant turning, and elongation defects. Re-introduction of wild-type cathD or its proteolytically-inactive mutant dramatically abolished these morphological defects. Moreover, cathD knockdown also led to dendritic defects in the adult mushroom bodies, suggesting that cathD-mediated processes are required in both the peripheral and central nervous systems. Taken together, our results demonstrate a critical role of cathD in shaping dendritic architecture independent of its proteolytic function.
ABSTRACT
The laterodorsal tegmentum (LDT) is a brain structure involved in distinct behaviors including arousal, reward, and innate fear. How environmental stimuli and top-down control from high-order sensory and limbic cortical areas converge and coordinate in this region to modulate diverse behavioral outputs remains unclear. Using a modified rabies virus, we applied monosynaptic retrograde tracing to the whole brain to examine the LDT cell type specific upstream nuclei. The LDT received very strong midbrain and hindbrain afferents and moderate cortical and hypothalamic innervation but weak connections to the thalamus. The main projection neurons from cortical areas were restricted to the limbic lobe, including the ventral orbital cortex (VO), prelimbic, and cingulate cortices. Although different cell populations received qualitatively similar inputs, primarily via afferents from the periaqueductal gray area, superior colliculus, and the LDT itself, parvalbumin-positive (PV) GABAergic cells received preferential projections from local LDT neurons. With regard to the different subtypes of GABAergic cells, a considerable number of nuclei, including those of the ventral tegmental area, central amygdaloid nucleus, and VO, made significantly greater inputs to somatostatin-positive cells than to PV cells. Diverse inputs to the LDT on a system-wide level were revealed.
ABSTRACT
Although extensively studied, the exact role of sleep in learning and memory is still not very clear. Sleep deprivation has been most frequently used to explore the effects of sleep on learning and memory, but the results from such studies are inevitably complicated by concurrent stress and distress. Furthermore, it is not clear whether there is a strict time-window between sleep and memory consolidation. In the present study we were able to induce time-locked slow-wave sleep (SWS) in mice by optogenetically stimulating GABAergic neurons in the parafacial zone (PZ), providing a direct approach to analyze the influences of SWS on learning and memory with precise time-windows. We found that SWS induced by light for 30 min immediately or 15 min after the training phase of the object-in-place task significantly prolonged the memory from 30 min to 6 h. However, induction of SWS 30 min after the training phase did not improve memory, suggesting a critical time-window between the induction of a brief episode of SWS and learning for memory consolidation. Application of a gentle touch to the mice during light stimulation to prevent SWS induction also failed to improve memory, indicating the specific role of SWS, but not the activation of PZ GABAergic neurons itself, in memory consolidation. Similar influences of light-induced SWS on memory consolidation also occurred for Y-maze spatial memory and contextual fear memory, but not for cued fear memory. SWS induction immediately before the test phase had no effect on memory performance, indicating that SWS does not affect memory retrieval. Thus, by induction of a brief-episode SWS we have revealed a critical time window for the consolidation of hippocampus-dependent memory.
Subject(s)
Animals , Mice , Cues , Electroencephalography , Electromyography , Evoked Potentials, Motor , Physiology , Fear , Psychology , Glutamate Decarboxylase , Metabolism , Hippocampus , Physiology , Light , Luminescent Proteins , Genetics , Metabolism , Maze Learning , Physiology , Memory Consolidation , Physiology , Mice, Inbred C57BL , Mice, Transgenic , Sleep Deprivation , Sleep, Slow-Wave , Physiology , Time Factors , Vesicular Inhibitory Amino Acid Transport Proteins , Genetics , MetabolismABSTRACT
Objective To investigate the efficacy and the indication and the management of perioperative complications in treatment of infra- kidney abdominal aortic aneurysm (AAA) by using endovascular graft exclusion (EVGE). Methods From April 2006 to September 2008, 24 patients with infra- kidney abdominal aortic aneurysms were diagnosed by contrast-enhanced CT or MRI scan. Vascular access was obtained through the bilateral femoral artery after arteriotomy and stent-graft was deployed into AAA of below the renal artery to occlude the left over cavity of AAA. The stent- graft was extended and anchored to the both side wall of AAA, the blood flow enter into the arteria iliaca communis through the sten't.Results Stent-graft deployment was successfully performed in all the patients. Immediate aortography after the procedure showed no leakage in 20 patients and the type Ⅰ minor leakage in 4 patients. No stent movement or organ and both lower extremities ischemia was found at the early post operative stage in all the patients. Six months after the operation, in all the 24 patients, contrast-enhanced CT scan showed the disappearance of the aneurysm and thrombosis at the level of the stent. Conclusions EVGE is simple,minimally invasive,less complication and quick recovery after operation. Thus it becomes first choice for the treatment of AAA for the elder patients.
ABSTRACT
Beijing has been one of the epicenters attacked most severely by the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) since the first patient was diagnosed in one of the city's hospitals. We now report complete genome sequences of the BJ Group, including four isolates (Isolates BJ01, BJ02, BJ03, and BJ04) of the SARS-CoV. It is remarkable that all members of the BJ Group share a common haplotype, consisting of seven loci that differentiate the group from other isolates published to date. Among 42 substitutions uniquely identified from the BJ group, 32 are non-synonymous changes at the amino acid level. Rooted phylogenetic trees, proposed on the basis of haplotypes and other sequence variations of SARS-CoV isolates from Canada, USA, Singapore, and China, gave rise to different paradigms but positioned the BJ Group, together with the newly discovered GD01 (GD-Ins29) in the same clade, followed by the H-U Group (from Hong Kong to USA) and the H-T Group (from Hong Kong to Toronto), leaving the SP Group (Singapore) more distant. This result appears to suggest a possible transmission path from Guangdong to Beijing/Hong Kong, then to other countries and regions.