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1.
Neurobiol Pain ; 16: 100160, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39252992

RESUMEN

Recent evidence suggests that the descending modulatory pathways from the brainstem rostral ventromedial medulla (RVM) are important for bladder inflammatory pain. This study aimed to identify the long-term molecular changes in RVM neurons due to early life cystitis during neuronal development and the effect of reexposure later in adulthood. RVM tissues from two treatment protocols were used: (1) neonatal zymosan exposures with acute adult rechallenge (RC) and (2) only neonatal zymosan exposures (NRC). RNAseq analysis showed upregulation of several genes associated with synaptic plasticity (Grin1, Grip2, Notch1, Arc, and Scn2b) in the cystitis groups compared to controls in both protocols. The RC protocol exhibited a stronger treatment effect with significantly higher fold differences between the groups compared to the NRC protocol (p < 0.001, fold differences RC vs NRC). In microarrays, miR-34a-5p showed cystitis-induced downregulation in both protocols. Bioinformatics analysis identified multiple 3'UTRs complementary binding sites for miR-34a-5p on Grin2b, Notch1, Grip2, Scn2b, and Arc genes. The enhanced response in the RC protocol indicates a possible priming effect of early life cystitis on rechallenge in adulthood. These long-term molecular alterations may play a critical role in the development of chronic bladder pain conditions as seen in patients with Interstitial Cystitis/Bladder pain syndrome.

2.
bioRxiv ; 2024 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-39229156

RESUMEN

Over a hundred risk genes underlie risk for autism spectrum disorder (ASD) but the extent to which they converge on shared downstream targets to increase ASD risk is unknown. To test the hypothesis that cellular context impacts the nature of convergence, here we apply a pooled CRISPR approach to target 29 ASD loss-of-function genes in human induced pluripotent stem cell (hiPSC)-derived neural progenitor cells, glutamatergic neurons, and GABAergic neurons. Two distinct approaches (gene-level and network-level analyses) demonstrate that convergence is greatest in mature glutamatergic neurons. Convergent effects are dynamic, varying in strength, composition, and biological role between cell types, increasing with functional similarity of the ASD genes examined, and driven by cell-type-specific gene co-expression patterns. Stratification of ASD genes yield targeted drug predictions capable of reversing gene-specific convergent signatures in human cells and ASD-related behaviors in zebrafish. Altogether, convergent networks downstream of ASD risk genes represent novel points of individualized therapeutic intervention.

3.
Brain Res Bull ; 217: 111079, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39270805

RESUMEN

Generalized fear is a maladaptive behavior in which non-threatening stimuli elicit a fearful response. The ventral tegmental area (VTA) has been demonstrated to play important roles in fear response and fear memory generalization, but the precious neural circuit mechanism is still unclear. Here, we demonstrated that VTA-zona incerta (ZI) glutamatergic projection is involved in regulating high-intensity threatening training induced generalization and anxiety. Combining calcium signal recording and chemogentics, our work reveals that VTA glutamatergic neurons respond to closed arm entering in the model of PTSD. Inhibition of VTA glutamatergic neurons or the glutamatergic projection to ZI could both relieve fear generalization and anxiety. Together, our study proves the VTA - ZI glutamatergic circuit is involved in mediating fear generalization and anxiety, and provides a potential target for treating post-traumatic stress disorder.

5.
Cereb Cortex ; 34(7)2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38960704

RESUMEN

The Polycomb Repressive Complex 2 (PRC2) regulates corticogenesis, yet the consequences of mutations to this epigenetic modifier in the mature brain are poorly defined. Importantly, PRC2 core genes are haploinsufficient and causative of several human neurodevelopmental disorders. To address the role of PRC2 in mature cortical structure and function, we conditionally deleted the PRC2 gene Eed from the developing mouse dorsal telencephalon. Adult homozygotes displayed smaller forebrain structures. Single-nucleus transcriptomics revealed that glutamatergic neurons were particularly affected, exhibiting dysregulated gene expression profiles, accompanied by aberrations in neuronal morphology and connectivity. Remarkably, homozygous mice performed well on challenging cognitive tasks. In contrast, while heterozygous mice did not exhibit clear anatomical or behavioral differences, they displayed dysregulation of neuronal genes and altered neuronal morphology that was strikingly different from homozygous phenotypes. Collectively, these data reveal how alterations to PRC2 function shape the mature brain and reveal a dose-specific role for PRC2 in determining glutamatergic neuron identity.


Asunto(s)
Ácido Glutámico , Neurogénesis , Neuronas , Complejo Represivo Polycomb 2 , Animales , Complejo Represivo Polycomb 2/genética , Complejo Represivo Polycomb 2/metabolismo , Neuronas/metabolismo , Neuronas/fisiología , Ratones , Neurogénesis/fisiología , Ácido Glutámico/metabolismo , Corteza Cerebral/crecimiento & desarrollo , Corteza Cerebral/metabolismo , Corteza Cerebral/citología , Masculino , Ratones Endogámicos C57BL , Femenino , Ratones Transgénicos
6.
Curr Med Sci ; 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38990450

RESUMEN

OBJECTIVE: Alzheimer's disease (AD) has become a significant global concern, but effective drugs able to slow down AD progression is still lacked. Electroacupuncture (EA) has been demonstrated to ameliorate cognitive impairment in individuals with AD. However, the underlying mechanisms remains poorly understood. This study aimed at examining the neuroprotective properties of EA and its potential mechanism of action against AD. METHODS: APP/PS1 transgenic mice were employed to evaluate the protective effects of EA on Shenshu (BL 23) and Baihui (GV 20). Chemogenetic manipulation was used to activate or inhibit serotonergic neurons within the dorsal raphe nucleus (DRN). Learning and memory abilities were assessed by the novel object recognition and Morris water maze tests. Golgi staining, western blot, and immunostaining were utilized to determine EA-induced neuroprotection. RESULTS: EA at Shenshu (BL 23) and Baihui (GV 20) effectively ameliorated learning and memory impairments in APP/PS1 mice. EA attenuated dendritic spine loss, increased the expression levels of PSD95, synaptophysin, and brain-derived neurotrophic factor in hippocampus. Activation of serotonergic neurons within the DRN can ameliorate cognitive deficits in AD by activating glutamatergic neurons mediated by 5-HT1B. Chemogenetic inhibition of serotonergic neurons in the DRN reversed the effects of EA on synaptic plasticity and memory. CONCLUSION: EA can alleviate cognitive dysfunction in APP/PS1 mice by activating serotonergic neurons in the DRN. Further study is necessary to better understand how the serotonergic neurons-related neural circuits involves in EA-induced memory improvement in AD.

7.
Acta Neuropathol Commun ; 12(1): 111, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38956662

RESUMEN

The genetic architecture of Parkinson's disease (PD) is complex and multiple brain cell subtypes are involved in the neuropathological progression of the disease. Here we aimed to advance our understanding of PD genetic complexity at a cell subtype precision level. Using parallel single-nucleus (sn)RNA-seq and snATAC-seq analyses we simultaneously profiled the transcriptomic and chromatin accessibility landscapes in temporal cortex tissues from 12 PD compared to 12 control subjects at a granular single cell resolution. An integrative bioinformatic pipeline was developed and applied for the analyses of these snMulti-omics datasets. The results identified a subpopulation of cortical glutamatergic excitatory neurons with remarkably altered gene expression in PD, including differentially-expressed genes within PD risk loci identified in genome-wide association studies (GWAS). This was the only neuronal subtype showing significant and robust overexpression of SNCA. Further characterization of this neuronal-subpopulation showed upregulation of specific pathways related to axon guidance, neurite outgrowth and post-synaptic structure, and downregulated pathways involved in presynaptic organization and calcium response. Additionally, we characterized the roles of three molecular mechanisms in governing PD-associated cell subtype-specific dysregulation of gene expression: (1) changes in cis-regulatory element accessibility to transcriptional machinery; (2) changes in the abundance of master transcriptional regulators, including YY1, SP3, and KLF16; (3) candidate regulatory variants in high linkage disequilibrium with PD-GWAS genomic variants impacting transcription factor binding affinities. To our knowledge, this study is the first and the most comprehensive interrogation of the multi-omics landscape of PD at a cell-subtype resolution. Our findings provide new insights into a precise glutamatergic neuronal cell subtype, causal genes, and non-coding regulatory variants underlying the neuropathological progression of PD, paving the way for the development of cell- and gene-targeted therapeutics to halt disease progression as well as genetic biomarkers for early preclinical diagnosis.


Asunto(s)
Redes Reguladoras de Genes , Neuronas , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/patología , Neuronas/metabolismo , Neuronas/patología , Masculino , Femenino , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Anciano , Factor de Transcripción YY1/genética , Factor de Transcripción YY1/metabolismo , Estudio de Asociación del Genoma Completo , Transcriptoma , Análisis de la Célula Individual , Lóbulo Temporal/metabolismo , Lóbulo Temporal/patología , Persona de Mediana Edad , Regulación de la Expresión Génica/genética , Multiómica
8.
Neurobiol Stress ; 31: 100654, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38948390

RESUMEN

Chronic pain can induce mood disorders and cognitive dysfunctions, such as anxiety, depression, and learning and memory impairment in humans. However, the specific neural network involved in anxiety- and depression-like behaviors and learning and memory impairment caused by chronic pain remains poorly understood. In this study, behavioral test results showed that chronic pain induced anxiety- and depression-like behaviors, and learning and memory impairment in male mice. c-Fos immunofluorescence and fiber photometry recording showed that glutamatergic neurons in the LH of mice with chronic pain were selectively activated. Next, the glutamatergic neurons of LH in normal mice were activated using optogenetic and chemogenetic methods, which recapitulates some of the depressive-like behaviors, as well as memory impairment, but not anxiety-like behavior. Finally, inhibition of glutamatergic neurons in the LH of mice with chronic pain, effectively relieved anxiety- and depression-like behaviors and learning and memory impairment. Taken together, our findings suggest that hyperexcitation of glutamatergic neurons in the LH is involved in depression-like behavior and learning and memory impairment induced by chronic pain.

9.
Neuroscience ; 552: 76-88, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-38909673

RESUMEN

Mesenchymal stromal cells (MSCs) hold therapeutic potential for neurological disorders, but their impact on neuronal activity remains unclear. We investigated the effects of SB623 cells (Notch-1 intracellular domain-transfected MSCs) and parental MSCs on human induced pluripotent stem cell (iPSC)-derived neurons using multi-electrode arrays. SB623 cells significantly increased neuronal activity and oscillation in a dose-dependent manner, surpassing astrocytes in promoting network bursts. Strikingly, glutamatergic neurons showed a rapid increase in activity and bursts compared to GABAergic neurons, suggesting glutamate release from SB623 cells. We confirmed this by finding high glutamate levels in SB623 cell conditioned medium, which were reduced by glutaminase inhibition. Glutamate release was further implicated by the reduced excitability in co-cultures with astrocytes, known glutamate scavengers. Our findings reveal a novel mechanism for MSCs: promoting neuronal activity and network formation through tonic glutamate release, with potential implications for MSC-based therapies.


Asunto(s)
Astrocitos , Técnicas de Cocultivo , Ácido Glutámico , Células Madre Pluripotentes Inducidas , Células Madre Mesenquimatosas , Neuronas , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/fisiología , Ácido Glutámico/metabolismo , Humanos , Neuronas/metabolismo , Neuronas/fisiología , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/fisiología , Astrocitos/metabolismo , Astrocitos/fisiología , Medios de Cultivo Condicionados/farmacología , Células Cultivadas , Potenciales de Acción/fisiología
10.
Mol Biol Evol ; 41(7)2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38913688

RESUMEN

The outstanding human cognitive capacities are computed in the cerebral cortex, a mammalian-specific brain region and the place of massive biological innovation. Long noncoding RNAs have emerged as gene regulatory elements with higher evolutionary turnover than mRNAs. The many long noncoding RNAs identified in neural tissues make them candidates for molecular sources of cerebral cortex evolution and disease. Here, we characterized the genomic and cellular shifts that occurred during the evolution of the long noncoding RNA repertoire expressed in the developing cerebral cortex and explored putative roles for these long noncoding RNAs in the evolution of the human brain. Using transcriptomics and comparative genomics, we comprehensively annotated the cortical transcriptomes of humans, rhesus macaques, mice, and chickens and classified human cortical long noncoding RNAs into evolutionary groups as a function of their predicted minimal ages. Long noncoding RNA evolutionary groups showed differences in expression levels, splicing efficiencies, transposable element contents, genomic distributions, and transcription factor binding to their promoters. Furthermore, older long noncoding RNAs showed preferential expression in germinative zones, outer radial glial cells, and cortical inhibitory (GABAergic) neurons. In comparison, younger long noncoding RNAs showed preferential expression in cortical excitatory (glutamatergic) neurons, were enriched in primate and human-specific gene co-expression modules, and were dysregulated in neurodevelopmental disorders. These results suggest different evolutionary routes for older and younger cortical long noncoding RNAs, highlighting old long noncoding RNAs as a possible source of molecular evolution of conserved developmental programs; conversely, we propose that the de novo expression of primate- and human-specific young long noncoding RNAs is a putative source of molecular evolution and dysfunction of cortical excitatory neurons, warranting further investigation.


Asunto(s)
Corteza Cerebral , Macaca mulatta , Neuronas , ARN Largo no Codificante , ARN Largo no Codificante/genética , Humanos , Corteza Cerebral/metabolismo , Animales , Ratones , Neuronas/metabolismo , Pollos/genética , Evolución Molecular , Transcriptoma
11.
Neurosci Bull ; 40(8): 1127-1140, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38767833

RESUMEN

The lateral parabrachial nucleus (PBL) is implicated in the regulation of respiratory activity. Sodium leak channel (NALCN) mutations disrupt the respiratory rhythm and influence anesthetic sensitivity in both rodents and humans. Here, we investigated whether the NALCN in PBL glutamatergic neurons maintains respiratory function under general anesthesia. Our results showed that chemogenetic activation of PBL glutamatergic neurons increased the respiratory frequency (RF) in mice; whereas chemogenetic inhibition suppressed RF. NALCN knockdown in PBL glutamatergic neurons but not GABAergic neurons significantly reduced RF under physiological conditions and caused more respiratory suppression under sevoflurane anesthesia. NALCN knockdown in PBL glutamatergic neurons did not further exacerbate the respiratory suppression induced by propofol or morphine. Under sevoflurane anesthesia, painful stimuli rapidly increased the RF, which was not affected by NALCN knockdown in PBL glutamatergic neurons. This study suggested that the NALCN is a key ion channel in PBL glutamatergic neurons that maintains respiratory frequency under volatile anesthetic sevoflurane but not intravenous anesthetic propofol.


Asunto(s)
Anestésicos por Inhalación , Neuronas , Núcleos Parabraquiales , Sevoflurano , Sevoflurano/farmacología , Animales , Núcleos Parabraquiales/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Anestésicos por Inhalación/farmacología , Ratones , Masculino , Canales de Sodio/efectos de los fármacos , Canales de Sodio/metabolismo , Propofol/farmacología , Ácido Glutámico/metabolismo , Ratones Endogámicos C57BL , Frecuencia Respiratoria/efectos de los fármacos , Respiración/efectos de los fármacos , Canales Iónicos , Proteínas de la Membrana
12.
Neuroscience ; 551: 1-16, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-38763224

RESUMEN

Functioning of the nervous system requires proper formation and specification of neurons as well as accurate connectivity and signalling between them. Locomotor behaviour depends upon these events that occur during neural development, and any aberration in them could result in motor disorders. Transcription factors are believed to be master regulators that control these processes, but very few linked to behaviour have been identified so far. The Drosophila homologue of BCL11A (CTIP1) and BCL11B (CTIP2), Chronophage (Cph), was recently shown to be involved in temporal patterning of neural stem cells but its role in post-mitotic neurons is not known. We show that knockdown of Cph in neurons during development results in animals with locomotor defects at both larval and adult stages. The defects are more severe in adults, with inability to stand, uncoordinated behaviour and complete loss of ability to walk, climb, or fly. These defects are similar to the motor difficulties observed in some patients with mutations in BCL11A and BCL11B. Electrophysiological recordings showed reduced evoked activity and irregular neuronal firing. All Cph-expressing neurons in the ventral nerve cord are glutamatergic. Our results imply that Cph modulates primary locomotor activity through configuration of glutamatergic neurons. Thus, this study ascribes a hitherto unknown role to Cph in locomotor behaviour of Drosophila melanogaster.


Asunto(s)
Proteínas de Drosophila , Drosophila melanogaster , Locomoción , Neuronas , Animales , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Locomoción/fisiología , Neuronas/metabolismo , Neuronas/fisiología , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Animales Modificados Genéticamente , Larva , Proteínas Portadoras/metabolismo , Proteínas Portadoras/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Proteínas Proto-Oncogénicas c-bcl-2
13.
Neurosci Bull ; 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38739251

RESUMEN

Irritable bowel syndrome (IBS) is a common functional bowel disorder characterized by abdominal pain and visceral hypersensitivity. Reducing visceral hypersensitivity is the key to effectively relieving abdominal pain in IBS. Increasing evidence has confirmed that the thalamic nucleus reuniens (Re) and 5-hydroxytryptamine (5-HT) neurotransmitter system play an important role in the development of colorectal visceral pain, whereas the exact mechanisms remain largely unclear. In this study, we found that high expression of the 5-HT2B receptors in the Re glutamatergic neurons promoted colorectal visceral pain. Specifically, we found that neonatal maternal deprivation (NMD) mice exhibited visceral hyperalgesia and enhanced spontaneous synaptic transmission in the Re brain region. Colorectal distension (CRD) stimulation induced a large amount of c-Fos expression in the Re brain region of NMD mice, predominantly in glutamatergic neurons. Furthermore, optogenetic manipulation of glutamatergic neuronal activity in the Re altered colorectal visceral pain responses in CON and NMD mice. In addition, we demonstrated that 5-HT2B receptor expression on the Re glutamatergic neurons was upregulated and ultimately promoted colorectal visceral pain in NMD mice. These findings suggest a critical role of the 5HT2B receptors on the Re glutamatergic neurons in the regulation of colorectal visceral pain.

14.
Hepatobiliary Surg Nutr ; 13(2): 258-272, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38617474

RESUMEN

Background: Visceral pain induced by pancreatic cancer seriously affects patients' quality of life, and there is no effective treatment, because the mechanism of its neural circuit is unknown. Therefore, the aim of this study is to explore the main neural circuit mechanism regulating visceral pain induced by pancreatic cancer in mice. Methods: The mouse model of pancreatic cancer visceral pain was established on C57BL/6N mice by pancreatic injection of mPAKPC-luc cells. Abdominal mechanical hyperalgesia and hunch score were performed to assess visceral pain; the pseudorabies virus (PRV) was used to identify the brain regions innervating the pancreas; the c-fos co-labeling method was used to ascertain the types of activated neurons; in vitro electrophysiological patch-clamp technique was used to record the electrophysiological activity of specific neurons; the calcium imaging technique was used to determine the calcium activity of specific neurons; specific neuron destruction and chemogenetics methods were used to explore whether specific neurons were involved in visceral pain induced by pancreatic cancer. Results: The PRV injected into the pancreas was detected in the paraventricular nucleus of the hypothalamus (PVN). Immunofluorescence staining showed that the majority of c-fos were co-labeled with glutamatergic neurons in the PVN. In vitro electrophysiological results showed that the firing frequency of glutamatergic neurons in the PVN was increased. The calcium imaging results showed that the calcium activity of glutamatergic neurons in the PVN was enhanced. Both specific destruction of glutamatergic neurons and chemogenetics inhibition of glutamatergic neurons in the PVN alleviated visceral pain induced by pancreatic cancer. Conclusions: Glutamatergic neurons in the PVN participate in the regulation of visceral pain induced by pancreatic cancer in mice, providing new insights for the discovery of effective targets for the treatment of pancreatic cancer visceral pain.

15.
Front Mol Neurosci ; 17: 1359154, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38638602

RESUMEN

A large number of synaptic proteins have been recurrently associated with complex brain disorders. One of these proteins, the Traf and Nck interacting kinase (TNIK), is a postsynaptic density (PSD) signaling hub, with many variants reported in neurodevelopmental disorder (NDD) and psychiatric disease. While rodent models of TNIK dysfunction have abnormal spontaneous synaptic activity and cognitive impairment, the role of mutations found in patients with TNIK protein deficiency and TNIK protein kinase activity during early stages of neuronal and synapse development has not been characterized. Here, using hiPSC-derived excitatory neurons, we show that TNIK mutations dysregulate neuronal activity in human immature synapses. Moreover, the lack of TNIK protein kinase activity impairs MAPK signaling and protein phosphorylation in structural components of the PSD. We show that the TNIK interactome is enriched in NDD risk factors and TNIK lack of function disrupts signaling networks and protein interactors associated with NDD that only partially overlap to mature mouse synapses, suggesting a differential role of TNIK in immature synapsis in NDD.

16.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(3): 420-427, 2024 Mar 20.
Artículo en Chino | MEDLINE | ID: mdl-38597432

RESUMEN

OBJECTIVE: To investigate the role of glutamatergic neurons in the dorsomedial periaqueductal grey (dmPAG) in regulating excessive defensive behaviors in mice with post-traumatic stress disorder (PTSD). METHODS: Eight-week-old male C57BL/6 mice were subjected to stereotactic injections of different recombinant adeno- associated viral vectors (rAAV2/9-CaMKII-mCherry, rAAV2/9-CaMKII-hM3Dq-mCherry and rAAV2/9-CaMKII-hM4Di-mCherry) into the bilateral dmPAG for chemogenetic activation or inhibition of the glutamatergic neurons, followed 2 weeks later by PTSD modeling by single prolonged stress. The looming test, response to whisker stimulation test and contextual fear conditioning (CFC) test were used to observe changes in defensive behaviors of the PTSD mice. The activity of glutamatergic neurons in the dmPAG were observed using immunofluorescence staining. RESULTS: Compared with the control mice, the mouse models of PTSD showed a shortened latency of flights with increased time spent in the nest, response scores of defensive behaviors and freezing time (all P<0.01). Immunofluorescence staining revealed significantly increased c-fos-positive glutamatergic neurons in the dmPAG of PTSD mice with defensive behaviors. Activation of the glutamatergic neurons in the dmPAG (in PTSD hM3Dq group) did not cause significant changes in the latency of flights or time in nest but obviously increased response scores of defensive behaviors and freezing time of the mice, whereas inhibiting the glutamatergic neurons in the dmPAG (in PTSD hM4Di group) caused the reverse changes and obviously alleviated defensive behaviors in the PTSD mice (P<0.05 or 0.01). CONCLUSION: Inhibiting the activity of glutamatergic neurons in the dmPAG can alleviate defensive behaviors in mice with PTSD.


Asunto(s)
Sustancia Gris Periacueductal , Trastornos por Estrés Postraumático , Ratas , Ratones , Masculino , Animales , Sustancia Gris Periacueductal/fisiología , Ratas Wistar , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Ratones Endogámicos C57BL , Neuronas
17.
Neuroscience ; 547: 37-55, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38604526

RESUMEN

The Aß hypothesis has long been central to Alzheimer's disease (AD) theory, with a recent surge in attention following drug approvals targeting Aß plaque clearance. Aß42 oligomers (AßO) are key neurotoxins. While ß-amyloid (Aß) buildup is a hallmark of AD, postmortem brain analyses have unveiled human islet amyloid polypeptide (hIAPP) deposition in AD patients, suggesting a potential role in Alzheimer's pathology. This study investigates the neurotoxic effects of co-aggregates of Aß42 and hIAPP, specifically focusing on their impact on cell survival, apoptosis, and AD-like pathology. We analyzed and compared the impact of AßO and Aß42-hIAPP on cell survival in SH-SY5Y cells, apoptosis and inducing AD-like pathology in glutamatergic neurons. Aß42-hIAPP co-oligomers exhibited significantly greater toxicity, causing 2.3-3.5 times higher cell death compared to AßO alone. Furthermore, apoptosis rates were significantly exacerbated in glutamatergic neurons when exposed to Aß42-hIAPP co-oligomers. The study also revealed that Aß42-hIAPP co-oligomers induced typical AD-like pathology in glutamatergic neurons, including the presence of Aß deposits (detected by 6E10 and 4G8 immunofluorescence) and alterations in tau protein (changes in total tau HT7, phosphorylated tau AT8, AT180). Notably, Aß42-hIAPP co-oligomers induced a more severe AD pathology compared to AßO alone. These findings provide compelling evidence for the heightened toxicity of Aß42-hIAPP co-oligomers on neurons and their role in exacerbating AD pathology. The study contributes novel insights into the pathogenesis of Alzheimer's disease, highlighting the potential involvement of hIAPP in AD pathology. Together, these findings offer novel insights into AD pathogenesis and routes for constructing animal models.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Apoptosis , Polipéptido Amiloide de los Islotes Pancreáticos , Humanos , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular , Polipéptido Amiloide de los Islotes Pancreáticos/metabolismo , Neuronas/metabolismo , Neuronas/patología , Neuronas/efectos de los fármacos , Fragmentos de Péptidos/metabolismo , Proteínas tau/metabolismo
18.
Front Aging Neurosci ; 16: 1357347, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38469164

RESUMEN

Introduction: Deterioration of cognitive functions is commonly associated with aging, although there is wide variation in the onset and manifestation. Albeit heterogeneity in age-related cognitive decline has been studied at the cellular and molecular level, there is poor evidence for electrophysiological correlates. The aim of the current study was to address the electrophysiological basis of heterogeneity of cognitive functions in cognitively Inferior and Superior old (19-20 months) rats in the ventral tegmental area (VTA) and the hippocampus, having Young (12 weeks) rats as a control. The midbrain VTA operates as a hub amidst affective and cognitive facets, processing sensory inputs related to motivated behaviours and hippocampal memory. Increasing evidence shows direct dopaminergic and non-dopaminergic input from the VTA to the hippocampus. Methods: Aged Superior and Inferior male rats were selected from a cohort of 88 animals based on their performance in a spatial learning and memory task. Using in vivo single-cell recording in the VTA, we examined the electrical activity of different neuronal populations (putative dopaminergic, glutamatergic and GABAergic neurons). In the same animals, basal synaptic transmission and synaptic plasticity were examined in hippocampal slices. Results: Electrophysiological recordings from the VTA and hippocampus showed alterations associated with aging per se, together with differences specifically linked to the cognitive status of aged animals. In particular, the bursting activity of dopamine neurons was lower, while the firing frequency of glutamatergic neurons was higher in VTA of Inferior old rats. The response to high-frequency stimulation in hippocampal slices also discriminated between Superior and Inferior aged animals. Discussion: This study provides new insight into electrophysiological information underlying compromised cerebral ageing. Further understanding of brain senescence, possibly related to neurocognitive decline, will help develop new strategies towards the preservation of a high quality of life.

19.
Sleep Biol Rhythms ; 22(1): 5-11, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38469582

RESUMEN

The pedunculopontine tegmental nucleus (PPTg) plays a vital role in sleep/wake states. There are three main kinds of heterogeneous neurons involved: cholinergic, glutamatergic, and gamma-aminobutyric acidergic (GABAergic) neurons. However, the precise roles of cholinergic, glutamatergic and GABAergic PPTg cell groups in regulating sleep-wake are unknown. Recent work suggests that the cholinergic, glutamatergic, and GABAergic neurons of the PPTg may activate the main arousal-promoting nucleus, thus exerting their wakefulness effects. We review the related projection pathways and functions of various neurons of the PPTg, especially the mechanisms of the PPTg in sleep-wake, thus providing new perspectives for research of sleep-wake mechanisms.

20.
BMC Neurosci ; 25(1): 12, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38438989

RESUMEN

BACKGROUND: Mutations in the gene DISC1 are associated with increased risk for schizophrenia, bipolar disorder and major depression. The study of mutated DISC1 represents a well-known and comprehensively characterized approach to understand neuropsychiatric disease mechanisms. However, previous studies have mainly used animal models or rather heterogeneous populations of iPSC-derived neurons, generated by undirected differentiation, to study the effects of DISC1 disruption. Since major hypotheses to explain neurodevelopmental, psychiatric disorders rely on altered neuronal connectivity observed in patients, an ideal iPSC-based model requires accurate representation of the structure and complexity of neuronal circuitries. In this study, we made use of an isogenic cell line with a mutation in DISC1 to study neuronal synaptic phenotypes in a culture system comprising a defined ratio of NGN2 and ASCL1/DLX2 (AD2)-transduced neurons, enriched for glutamatergic and GABAergic neurons, respectively, to mimic properties of the cortical microcircuitry. RESULTS: In heterozygous DISC1 mutant neurons, we replicated the expected phenotypes including altered neural progenitor proliferation as well as neurite outgrowth, deregulated DISC1-associated signaling pathways, and reduced synaptic densities in cultures composed of glutamatergic neurons. Cultures comprising a defined ratio of NGN2 and AD2 neurons then revealed considerably increased GABAergic synapse densities, which have not been observed in any iPSC-derived model so far. Increased inhibitory synapse densities could be associated with an increased efficiency of GABAergic differentiation, which we observed in AD2-transduced cultures of mutant neurons. Additionally, we found increased neuronal activity in GABAergic neurons through calcium imaging while the activity pattern of glutamatergic neurons remained unchanged. CONCLUSIONS: In conclusion, our results demonstrate phenotypic differences in a co-culture comprising a defined ratio of DISC1 mutant NGN2 and AD2 neurons, as compared to culture models comprising only one neuronal cell type. Altered synapse numbers and neuronal activity imply that DISC1 impacts the excitatory/inhibitory balance in NGN2/AD2 co-cultures, mainly through increased GABAergic input.


Asunto(s)
Trastorno Bipolar , Trastorno Depresivo Mayor , Animales , Humanos , Técnicas de Cocultivo , Neuronas GABAérgicas , Mutación , Proteínas del Tejido Nervioso/genética
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