scholarly journals Biphasic impact of prenatal inflammation and macrophage depletion on the wiring of neocortical inhibitory circuits

2019 ◽  
Author(s):  
Morgane Sonia Thion ◽  
Coralie-Anne Mosser ◽  
Isabelle Férézou ◽  
Pauline Grisel ◽  
Sofia Baptista ◽  
...  

SUMMARYThe etiology of neurodevelopmental disorders is linked to defects in Parvalbumin (PV)-expressing cortical interneurons and to prenatal immune challenges. Mouse models of maternal immune activation (MIA) and microglia deficits increase the postnatal density of PV interneurons, raising the question of their functional integration. Here, we show that MIA and embryonic depletion of macrophages including microglia, have a two-step impact on PV interneurons wiring onto their excitatory target neurons in the barrel cortex. In adults, both challenges reduced the inhibitory drive from PV interneurons, as reported in neurodevelopmental disorders. In juveniles, however, we found an increased density of PV neurons, an enhanced strength of unitary connections onto excitatory cells and an aberrant horizontal inhibition with a reduced lateral propagation of sensory inputs in vivo. Our results provide a novel framework for understanding the impact of prenatal immune challenges onto the developmental trajectory of inhibitory circuits that leads to pathological brain wiring.

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Mathieu Niquille ◽  
Greta Limoni ◽  
Foivos Markopoulos ◽  
Christelle Cadilhac ◽  
Julien Prados ◽  
...  

Delineating the basic cellular components of cortical inhibitory circuits remains a fundamental issue in order to understand their specific contributions to microcircuit function. It is still unclear how current classifications of cortical interneuron subtypes relate to biological processes such as their developmental specification. Here we identified the developmental trajectory of neurogliaform cells (NGCs), the main effectors of a powerful inhibitory motif recruited by long-range connections. Using in vivo genetic lineage-tracing in mice, we report that NGCs originate from a specific pool of 5-HT3AR-expressing Hmx3+ cells located in the preoptic area (POA). Hmx3-derived 5-HT3AR+ cortical interneurons (INs) expressed the transcription factors PROX1, NR2F2, the marker reelin but not VIP and exhibited the molecular, morphological and electrophysiological profile of NGCs. Overall, these results indicate that NGCs are a distinct class of INs with a unique developmental trajectory and open the possibility to study their specific functional contribution to cortical inhibitory microcircuit motifs.


2021 ◽  
Author(s):  
Lloyd E. Russell ◽  
Henry W.P. Dalgleish ◽  
Rebecca Nutbrown ◽  
Oliver Gauld ◽  
Dustin Herrmann ◽  
...  

Recent advances combining two-photon calcium imaging and two-photon optogenetics with digital holography now allow us to read and write neural activity in vivo at cellular resolution with millisecond temporal precision. Such 'all-optical' techniques enable experimenters to probe the impact of functionally defined neurons on neural circuit function and behavioural output with new levels of precision. This protocol describes the experimental strategy and workflow for successful completion of typical all-optical interrogation experiments in awake, behaving head-fixed mice. We describe modular procedures for the setup and calibration of an all-optical system, the preparation of an indicator and opsin-expressing and task-performing animal, the characterization of functional and photostimulation responses and the design and implementation of an all-optical experiment. We discuss optimizations for efficiently selecting and targeting neuronal ensembles for photostimulation sequences, as well as generating photostimulation response maps from the imaging data that can be used to examine the impact of photostimulation on the local circuit. We demonstrate the utility of this strategy using all-optical experiments in three different brain areas - barrel cortex, visual cortex and hippocampus - using different experimental setups. This approach can in principle be adapted to any brain area for all-optical interrogation experiments to probe functional connectivity in neural circuits and for investigating the relationship between neural circuit activity and behaviour.


2020 ◽  
Author(s):  
Rahel Kastli ◽  
Rasmus Vighagen ◽  
Alexander van der Bourg ◽  
Ali Ozgur Argunsah ◽  
Asim Iqbal ◽  
...  

AbstractTwo inhibitory cell types involved in modulating barrel cortex activity and perception during active whisking in adult mice, are the VIP+ and SST+ interneurons. Here we identify a developmental transition point of structural and functional rearrangements onto these interneuron types around the start of active sensation at P14. Using in vivo two-photon Ca2+ imaging, we find that before P14, both interneuron types respond stronger to a multi-whisker stimulus, whereas after P14 their responses diverge, with VIP+ cells losing their multi-whisker preference and SST+ neurons enhancing theirs. Rabies virus tracings followed by tissue clearing, as well as photostimulation-coupled electrophysiology reveal that SST+ cells receive higher cross-barrel inputs compared to VIP+ at both time points. In addition, we also uncover that whereas prior to P14 both cell types receive direct input from the sensory thalamus, after P14 VIP+ cells show reduced inputs and SST+ cells largely shift to motor-related thalamic nuclei.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rahel Kastli ◽  
Rasmus Vighagen ◽  
Alexander van der Bourg ◽  
Ali Özgür Argunsah ◽  
Asim Iqbal ◽  
...  

AbstractVasocative-intestinal-peptide (VIP+) and somatostatin (SST+) interneurons are involved in modulating barrel cortex activity and perception during active whisking. Here we identify a developmental transition point of structural and functional rearrangements onto these interneurons around the start of active sensation at P14. Using in vivo two-photon Ca2+ imaging, we find that before P14, both interneuron types respond stronger to a multi-whisker stimulus, whereas after P14 their responses diverge, with VIP+ cells losing their multi-whisker preference and SST+ neurons enhancing theirs. Additionally, we find that Ca2+ signaling dynamics increase in precision as the cells and network mature. Rabies virus tracings followed by tissue clearing, as well as photostimulation-coupled electrophysiology reveal that SST+ cells receive higher cross-barrel inputs compared to VIP+ neurons at both time points. In addition, whereas prior to P14 both cell types receive direct input from the sensory thalamus, after P14 VIP+ cells show reduced inputs and SST+ cells largely shift to motor-related thalamic nuclei.


2018 ◽  
Author(s):  
Phillip O’Herron ◽  
Phillip M. Summers ◽  
Andy Y. Shih ◽  
Prakash Kara ◽  
John J. Woodward

AbstractThe effects of ethanol on brain function have been extensively studied using a variety of in vitro and in vivo techniques. For example, electrophysiological studies using brain slices from rodents and nonhuman primates have demonstrated that acute and chronic exposure to ethanol alters the intrinsic excitability and synaptic signaling of neurons within cortical and sub-cortical areas of the brain. In humans, neuroimaging studies reveal alterations in measures of brain activation and connectivity in subjects with alcohol use disorders. While complementary, these methods are inherently limited due to issues related to either disruption of normal sensory input (in vitro slice studies) or resolution (whole brain imaging). In the present study, we used 2-photon laser scanning microscopy in intact animals to assess the impact of chronic ethanol exposure on sensory evoked neuronal and vascular responses. Adult male C57BL/6J mice were exposed to 4 weekly cycles of chronic intermittent ethanol (CIE) exposure while control mice were exposed to air. After withdrawal (≤ 72 hr), a cranial window was placed over the primary visual cortex (V1) and sensory evoked responses were monitored using the calcium indicator OGB-1. CIE exposure produced small but significant changes in response amplitude (decrease) and orientation selectivity of V1 neurons (increase). While arteriole diameter did not differ between control and CIE mice under baseline conditions, sensory-evoked dilation was enhanced in vessels from CIE exposed mice as compared to controls. This was accompanied by a reduced latency in response to stimulation. In separate experiments, pial arteriole diameter was measured in the barrel cortex of control and CIE exposed mice. Baseline diameter of barrel cortex arterioles was similar between control and CIE exposed mice but unlike vessels in V1, sensory-evoked dilation of barrel cortex arterioles was similar between the two groups. Together the results of these studies suggest that chronic exposure to alcohol induces changes in neurovascular coupling that are region dependent.


2014 ◽  
Vol 1 (3) ◽  
pp. 3-7
Author(s):  
O. Zhukorskyy ◽  
O. Hulay

Aim. To estimate the impact of in vivo secretions of water plantain (Alisma plantago-aquatica) on the popula- tions of pathogenic bacteria Erysipelothrix rhusiopathiae. Methods. The plants were isolated from their natural conditions, the roots were washed from the substrate residues and cultivated in laboratory conditions for 10 days to heal the damage. Then the water was changed; seven days later the selected samples were sterilized using fi lters with 0.2 μm pore diameter. The dilution of water plantain root diffusates in the experimental samples was 1:10–1:10,000. The initial density of E. rhusiopathiae bacteria populations was the same for both experimental and control samples. The estimation of the results was conducted 48 hours later. Results. When the dilution of root diffusates was 1:10, the density of erysipelothrixes in the experimental samples was 11.26 times higher than that of the control, on average, the dilution of 1:100 − 6.16 times higher, 1:1000 – 3.22 times higher, 1:10,000 – 1.81 times higher, respectively. Conclusions. The plants of A. plantago-aquatica species are capable of affecting the populations of E. rhusiopathiae pathogenic bacteria via the secretion of biologically active substances into the environment. The consequences of this interaction are positive for the abovementioned bacteria, which is demon- strated by the increase in the density of their populations in the experiment compared to the control. The intensity of the stimulating effect on the populations of E. rhusiopathiae in the root diffusates of A. plantago-aquatica is re- ciprocally dependent on the degree of their dilution. The investigated impact of water plantain on erysipelothrixes should be related to the topical type of biocenotic connections, the formation of which between the test species in the ecosystems might promote maintaining the potential of natural focus of rabies. Keywords: Alisma plantago-aquatica, in vivo secretions, Erysipelothrix rhusiopathiae, population density, topical type of connections.


Author(s):  
Hossam Ebaid ◽  
Mohamed Habila ◽  
Iftekhar Hassan ◽  
Jameel Al-Tamimi ◽  
Mohamed S. Omar ◽  
...  

Background: Hepatotoxicity remains an important clinical challenge. Hepatotoxicity observed in response to toxins and hazardous chemicals may be alleviated by delivery of the curcumin in silver nanoparticles (AgNPs-curcumin). In this study, we examined the impact of AgNPs-curcumin in a mouse model of carbon tetrachloride (CCl4)-induced hepatic injury. Methods: Male C57BL/6 mice were divided into three groups (n=8 per group). Mice in group 1 were treated with vehicle control alone, while mice in Group 2 received a single intraperitoneal injection of 1 ml/kg CCl4 in liquid paraffin (1:1 v/v). Mice in group 3 were treated with 2.5 mg/kg AgNPs-curcumin twice per week for three weeks after the CCl4 challenge. Results: Administration of CCL4 resulted in oxidative dysregulation, including significant reductions in reduced glutathione and concomitant elevations in the level of malondialdehyde (MDA). CCL4 challenge also resulted in elevated levels of serum aspartate transaminase (AST) and alanine transaminase (ALT); these findings were associated with the destruction of hepatic tissues. Treatment with AgNPs-curcumin prevented oxidative imbalance, hepatic dysfunction, and tissue destruction. A comet assay revealed that CCl4 challenge resulted in significant DNA damage as documented by a 70% increase in nuclear DNA tail-length; treatment with AgNPs-curcumin inhibited the CCL4-mediated increase in nuclear DNA tail-length by 34%. Conclusion: Administration of AgNPs-curcumin resulted in significant antioxidant activity in vivo. This agent has the potential to prevent the hepatic tissue destruction and DNA damage that results from direct exposure to CCL4.


The prevalence of cognitive impairment caused by neurodegenerative diseases and other neurologic disorders associated with aging is expected to rise dramatically between now and year 2050, when the population of Americans aged 65 or older will nearly double. Cognitive impairment also commonly occurs in other neurologic conditions, as well as in non-neurologic medical disorders (and their treatments), idiopathic psychiatric illnesses, and adult neurodevelopmental disorders. Cognitive impairment can thus infiltrate all aspects of healthcare, making it necessary for clinicians and clinical researchers to have an integrated knowledge of the spectrum of adult cognitive disorders. The Oxford Handbook of Adult Cognitive Disorders is meant to serve as an up-to-date, scholarly, and comprehensive volume covering most diseases, conditions, and injuries resulting in impairments in cognitive function in adults. Topics covered include normal cognitive and brain aging, the impact of medical disorders (e.g., cardiovascular, liver, pulmonary) and psychiatric illnesses (e.g., depression and bipolar disorder) on cognitive function, adult neurodevelopmental disorders (e.g., Down Syndrome, Attention Deficit/Hyperactivity Disorder), as well as the various neurological conditions (e.g., Alzheimer’s disease, chronic traumatic encephalopathy, concussion). A section of the Handbook is also dedicated to unique perspectives and special considerations for the clinicians and clinical researchers, covering topics such as cognitive reserve, genetics, diversity, and neuroethics. The target audience of this Handbook includes: (1) clinicians, particularly psychologists, neuropsychologists, neurologists (including behavioral and cognitive neurologists), geriatricians, and psychiatrists (including neuropsychiatrists), who provide clinical care and management for adults with a diverse range of cognitive disorders; (2) clinical researchers who investigate cognitive outcomes and functioning in adult populations; and (3) graduate level students and post-doctoral trainees studying psychology, clinical neuroscience, and various medical specialties.


2013 ◽  
Vol 150 (3) ◽  
pp. 1024-1031 ◽  
Author(s):  
Mohammad Hossein Boskabady ◽  
Sakine Shahmohammadi Mehrjardi ◽  
Abadorrahim Rezaee ◽  
Houshang Rafatpanah ◽  
Sediqeh Jalali

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroaki Kanzaki ◽  
Tetsuhiro Chiba ◽  
Junjie Ao ◽  
Keisuke Koroki ◽  
Kengo Kanayama ◽  
...  

AbstractFGF19/FGFR4 autocrine signaling is one of the main targets for multi-kinase inhibitors (MKIs). However, the molecular mechanisms underlying FGF19/FGFR4 signaling in the antitumor effects to MKIs in hepatocellular carcinoma (HCC) remain unclear. In this study, the impact of FGFR4/ERK signaling inhibition on HCC following MKI treatment was analyzed in vitro and in vivo assays. Serum FGF19 in HCC patients treated using MKIs, such as sorafenib (n = 173) and lenvatinib (n = 40), was measured by enzyme-linked immunosorbent assay. Lenvatinib strongly inhibited the phosphorylation of FRS2 and ERK, the downstream signaling molecules of FGFR4, compared with sorafenib and regorafenib. Additional use of a selective FGFR4 inhibitor with sorafenib further suppressed FGFR4/ERK signaling and synergistically inhibited HCC cell growth in culture and xenograft subcutaneous tumors. Although serum FGF19high (n = 68) patients treated using sorafenib exhibited a significantly shorter progression-free survival and overall survival than FGF19low (n = 105) patients, there were no significant differences between FGF19high (n = 21) and FGF19low (n = 19) patients treated using lenvatinib. In conclusion, robust inhibition of FGF19/FGFR4 is of importance for the exertion of antitumor effects of MKIs. Serum FGF19 levels may function as a predictive marker for drug response and survival in HCC patients treated using sorafenib.


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