Response Of Neural Cells Research Articles

Senescence in neural cell lines: comparative insights from SH-SY5Y and ReNcell VM.

Senescence, a crucial yet paradoxical phenomenon in cellular biology, acts as a barrier against cancer progression while simultaneously promoting aging and age-related pathologies. This duality underlines the importance of precise monitoring of senescence response, especially with regard to the proposed use of drugs selectively removing senescent cells. In particular, little is known about the role of senescence in neurons and in neurodegenerative diseases. Our study investigates the senescence response in neuroblastoma SH-SY5Y cells and human neural progenitor ReNcell VM cells exposed to doxorubicin, a chemotherapeutic agent known to induce DNA damage and subsequent senescence. Through a comprehensive analysis employing the most robust senescence markers, we characterized the senescence-associated patterns in these neural cell lines including cellular morphological changes, SA-beta-gal, γH2A.X, p21Waf1/Cip1 and p16Ink4a. Our findings indicate that ReNcell VM cells exhibit greater senescence-associated response at lower doxorubicin concentrations compared to SH-SY5Y cells. Additionally, we observed cell-type-specific differences in timing and levels of the expression of key cell cycle regulators during senescence. Our results emphasize the necessity of cell-type-specific strategies in senescence research with regard to implications as well as limitations for translation into aging and neurodegenerative disorders.

Near-infrared light induces neurogenesis and modulates anxiety-like behavior

BackgroundThe hippocampus is associated with mood disorders, and the activation of quiescent neurogenesis has been linked to anxiolytic effects. Near-infrared (NIR) light has shown potential to improve learning and memory in human and animal models. Despite the vast amount of information regarding the effect of visible light, there is a significant gap in our understanding regarding the response of neural stem cells (NSCs) to NIR stimulation, particularly in anxiety-like behavior. The present study aimed to develop a new optical manipulation approach to stimulate hippocampal neurogenesis and understand the mechanisms underlying its anxiolytic effects.MethodsWe used 940 nm NIR (40 Hz) light exposure to stimulate hippocampal stem cells in C57BL/6 mice. The enhanced proliferation and astrocyte differentiation of NIR-treated NSCs were assessed using 5-ethynyl-2’-deoxyuridine (EdU) incorporation and immunofluorescence assays. Additionally, we evaluated calcium activity of NIR light-treated astrocytes using GCaMP6f recording through fluorescence fiber photometry. The effects of NIR illumination of the hippocampus on anxiety-like behaviors were evaluated using elevated plus maze and open-field test.ResultsNIR light effectively promoted NSC proliferation and astrocyte differentiation via the OPN4 photoreceptor. Furthermore, NIR stimulation significantly enhanced neurogenesis and calcium-dependent astrocytic activity. Moreover, activating hippocampal astrocytes with 40-Hz NIR light substantially improved anxiety-like behaviors in mice.ConclusionsWe found that flickering NIR (940 nm/40Hz) light illumination improved neurogenesis in the hippocampus with anxiolytic effects. This innovative approach holds promise as a novel preventive treatment for depression.

Neural Cell Interactions with a Surgical Grade Biomaterial Using a Simulated Injury in Brain Organotypic Slices.

Tissue engineering research for neurological applications has demonstrated that biomaterial-based structural bridges present a promising approach for promoting regeneration. This is particularly relevant for penetrating traumatic brain injuries, where the clinical prognosis is typically poor, with no available regeneration-enhancing therapies. Specifically, repurposing clinically approved biomaterials offers many advantages (reduced approval time and achieving commercial scaleup for clinical applications), highlighting the need for detailed screening of potential neuromaterials. A major challenge in experimental testing is the limited availability of neuromimetic, technically accessible, cost-effective, and humane models of neurological injury for efficient biomaterial testing in injury-simulated environments. Three dimensional (3D) organotypic brain slices bridge the gap between live animal models and simplified co-cultures and are a versatile tool for studies on neural development, neurodegenerative disease and in drug testing. Despite this, their utility for investigation of neural cell responses to biomaterial implantation is poorly investigated. We demonstrate that murine brain organotypic slices can be used to develop a model of penetrating traumatic brain injury, wherein a surgical-grade biomaterial scaffold can be implanted into the lesion cavity. Critically, the model allowed for examination of key cellular responses involved in CNS injury pathology/biomaterial handling: astrogliosis, microglial activation and axonal sprouting. The approach offers a technically simple and versatile methodology to study biomaterial interventions as a regenerative therapy for neurological injuries.

Cortical spheroids show strain-dependent cell viability loss and neurite disruption following sustained compression injury.

Sustained compressive injury (SCI) in the brain is observed in numerous injury and pathological scenarios, including tumors, ischemic stroke, and traumatic brain injury-related tissue swelling. Sustained compressive injury is characterized by tissue loading over time, and currently, there are few in vitro models suitable to study neural cell responses to strain-dependent sustained compressive injury. Here, we present an in vitro model of sustained compressive neural injury via centrifugation. Spheroids were made from neonatal rat cortical cells seeded at 4000 cells/spheroid and cultured for 14 days in vitro. A subset of spheroids was centrifuged at 104, 209, 313 or 419 rads/s for 2 minutes. Modeling the physical deformation of the spheroids via finite element analyses, we found that spheroids centrifuged at the aforementioned angular velocities experienced pressures of 10, 38, 84 and 149 kPa, respectively, and compressive (resp. tensile) strains of 10% (5%), 18% (9%), 27% (14%) and 35% (18%), respectively. Quantification of LIVE-DEAD assay and Hoechst 33342 nuclear staining showed that centrifuged spheroids subjected to pressures above 10 kPa exhibited significantly higher DNA damage than control spheroids at 2, 8, and 24 hours post-injury. Immunohistochemistry of β3-tubulin networks at 2, 8, and 24 hours post-centrifugation injury showed increasing degradation of microtubules over time with increasing strain. Our findings show that cellular injuries occur as a result of specific levels and timings of sustained tissue strains. This experimental SCI model provides a high throughput in vitro platform to examine cellular injury, to gain insights into brain injury that could be targeted with therapeutic strategies.

Interface-Mediated Neurogenic Signaling: The Impact of Surface Geometry and Chemistry on Neural Cell Behavior for Regenerative and Brain-Machine Interfacing Applications.

Nanomaterial advancements have driven progress in central and peripheral nervous system applications such as tissue regeneration and brain-machine interfacing. Ideally, neural interfaces with native tissue shall seamlessly integrate, a process that is often mediated by the interfacial material properties. Surface topography and material chemistry are significant extracellular stimuli that can influence neural cell behavior to facilitate tissue integration and augment therapeutic outcomes. This review characterizes topographical modifications, including micropillars, microchannels, surface roughness, and porosity, implemented on regenerative scaffolding and brain-machine interfaces. Their impact on neural cell response is summarized through neurogenic outcome and mechanistic analysis. The effects of surface chemistry on neural cell signaling with common interfacing compounds like carbon-based nanomaterials, conductive polymers, and biologically inspired matrices are also reviewed. Finally, the impact of these extracellular mediated neural cues on intracellular signaling cascades is discussed to provide perspective on the manipulation of neuron and neuroglia cell microenvironments to drive therapeutic outcomes.

TYK2 as a novel therapeutic target in Alzheimer's Disease with TDP-43 inclusions.

Neuroinflammation is a pathological feature of many neurodegenerative diseases, including Alzheimer's disease (AD)1,2 and amyotrophic lateral sclerosis (ALS)3, raising the possibility of common therapeutic targets. We previously established that cytoplasmic double-stranded RNA (cdsRNA) is spatially coincident with cytoplasmic pTDP-43 inclusions in neurons of patients with C9ORF72-mediated ALS4. CdsRNA triggers a type-I interferon (IFN-I)-based innate immune response in human neural cells, resulting in their death4. Here, we report that cdsRNA is also spatially coincident with pTDP-43 cytoplasmic inclusions in brain cells of patients with AD pathology and that type-I interferon response genes are significantly upregulated in brain regions affected by AD. We updated our machine-learning pipeline DRIAD-SP (Drug Repurposing In Alzheimer's Disease with Systems Pharmacology) to incorporate cryptic exon (CE) detection as a proxy of pTDP-43 inclusions and demonstrated that the FDA-approved JAK inhibitors baricitinib and ruxolitinib that block interferon signaling show a protective signal only in cortical brain regions expressing multiple CEs. Furthermore, the JAK family member TYK2 was a top hit in a CRISPR screen of cdsRNA-mediated death in differentiated human neural cells. The selective TYK2 inhibitor deucravacitinib, an FDA-approved drug for psoriasis, rescued toxicity elicited by cdsRNA. Finally, we identified CCL2, CXCL10, and IL-6 as candidate predictive biomarkers for cdsRNA-related neurodegenerative diseases. Together, we find parallel neuroinflammatory mechanisms between TDP-43 associated-AD and ALS and nominate TYK2 as a possible disease-modifying target of these incurable neurodegenerative diseases.

Maternal environmental enrichment protects neonatal brains from hypoxic-ischemic challenge by mitigating brain energetic dysfunction and modulating glial cell responses

There is evidence that maternal milieu and changes in environmental factors during the prenatal period may exert a lasting impact on the brain health of the newborn, even in case of neonatal brain hypoxia-ischemia (HI). The present study aimed to investigate the effects of maternal environmental enrichment (EE) on HI-induced energetic and metabolic failure, along with subsequent neural cell responses in the early postnatal period. Male Wistar pups born to dams exposed to maternal EE or standard conditions (SC) were randomly divided into Sham-SC, HI-SC, Sham-EE, and HI-EE groups. Neonatal HI was induced on postnatal day (PND) 3. The Na+,K+-ATPase activity, mitochondrial function and neuroinflammatory related-proteins were assessed at 24 h and 48 h after HI. MicroPET-FDG scans were used to measure glucose uptake at three time points: 24 h post-HI, PND18, and PND24. Moreover, neuronal preservation and glial cell responses were evaluated at PND18. After HI, animals exposed to maternal EE showed an increase in Na+,K+-ATPase activity, preservation of mitochondrial potential/mass ratio, and a reduction in mitochondrial swelling. Glucose uptake was preserved in HI-EE animals from PND18 onwards. Maternal EE attenuated HI-induced cell degeneration, white matter injury, and reduced astrocyte immunofluorescence. Moreover, the HI-EE group exhibited elevated levels of IL-10 and a reduction in Iba-1 positive cells. Data suggested that the regulation of AKT/ERK1/2 signaling pathways could be involved in the effects of maternal EE. This study evidenced that antenatal environmental stimuli could promote bioenergetic and neural resilience in the offspring against early HI damage, supporting the translational value of pregnancy-focused environmental treatments.

Space Flight Enhances Stress Pathways in Human Neural Stem Cells.

Mammalian cells have evolved to function under Earth's gravity, but how they respond to microgravity remains largely unknown. Neural stem cells (NSCs) are essential for the maintenance of central nervous system (CNS) functions during development and the regeneration of all CNS cell populations. Here, we examined the behavior of space (SPC)-flown NSCs as they readapted to Earth's gravity. We found that most of these cells survived the space flight and self-renewed. Yet, some showed enhanced stress responses as well as autophagy-like behavior. To ascertain if the secretome from SPC-flown NSCs contained molecules inducing these responses, we incubated naïve, non-starved NSCs in a medium containing SPC-NSC secretome. We found a four-fold increase in stress responses. Proteomic analysis of the secretome revealed that the protein of the highest content produced by SPC-NSCs was secreted protein acidic and rich in cysteine (SPARC), which induces endoplasmic reticulum (ER) stress, resulting in the cell's demise. These results offer novel knowledge on the response of neural cells, particularly NSCs, subjected to space microgravity. Moreover, some secreted proteins have been identified as microgravity sensing, paving a new venue for future research aiming at targeting the SPARC metabolism. Although we did not establish a direct relationship between microgravity-induced stress and SPARC as a potential marker, these results represent the first step in the identification of gravity sensing molecules as targets to be modulated and to design effective countermeasures to mitigate intracranial hypertension in astronauts using structure-based protein design.

Response of Neural Stem Cells to Developmental, Homeostatic and Aging cues

Response of Neural Stem Cells to Developmental, Homeostatic and Aging cues

Exploring the heterogeneous transcriptional response of the CNS to systemic LPS and Poly(I:C)

Peripheral contact to pathogen-associated molecular patterns (PAMPs) evokes a systemic innate immune response which is rapidly relayed to the central nervous system (CNS). The remarkable cellular heterogeneity of the CNS poses a significant challenge to the study of cell type and stimulus dependent responses of neural cells during acute inflammation.Here we utilized single nuclei RNA sequencing (snRNAseq), serum proteome profiling and primary cell culture methods to systematically compare the acute response of the mammalian brain to the bacterial PAMP lipopolysaccharide (LPS) and the viral PAMP polyinosinic:polycytidylic acid (Poly(I:C)), at single cell resolution.Our study unveiled convergent transcriptional cytokine and cellular stress responses in brain vascular and ependymal cells and a downregulation of several key mediators of directed blood brain barrier (BBB) transport. In contrast the neuronal response to PAMPs was limited in acute neuroinflammation. Moreover, our study highlighted the dominant role of IFN signalling upon Poly(I:C) challenge, particularly in cells of the oligodendrocyte lineage.Collectively our study unveils heterogeneous, shared and distinct cell type and stimulus dependent acute responses of the CNS to bacterial and viral PAMP challenges. Our findings highlight inflammation induced dysregulations of BBB-transporter gene expression, suggesting potential translational implications on drug pharmacokinetics variability during acute neuroinflammation. The pronounced dependency of oligodendrocytes on IFN stimulation during viral PAMP challenges, emphasizes their limited molecular viral response repertoire.

Sestrin2 protects against hypoxic nerve injury by regulating mitophagy through SESN2/AMPK pathway.

Hypoxia induced by high altitude can lead to severe neurological dysfunction. Mitophagy is known to play a crucial role in hypoxic nerve injury. However, the regulatory mechanism of mitophagy during this injury remains unclear. Recent studies have highlighted the role of Sestrin2 (SESN2), an evolutionarily conserved stress-inducible protein against acute hypoxia. Our study demonstrated that hypoxia treatment increased SESN2 expression and activated mitophagy in PC12 cells. Furthermore, the knock-out of Sesn2 gene led to a significant increase in mitochondrial membrane potential and ATP concentrations, which protected the PC12 cells from hypoxic injury. Although the AMPK/mTOR pathway was significantly altered under hypoxia, it does not seem to participate in mitophagy regulation. Instead, our data suggest that the mitophagy receptor FUNDC1 plays a vital role in hypoxia-induced mitophagy. Moreover, SESN2 may function through synergistic regulation with other pathways, such as SESN2/AMPK, to mediate cellular adaptation to hypoxia, including the regulation of mitophagy in neuron cells. Therefore, SESN2 plays a critical role in regulating neural cell response to hypoxia. These findings offer valuable insights into the underlying molecular mechanisms governing the regulation of mitophagy under hypoxia and further highlight the potential of SESN2 as a promising therapeutic target for hypoxic nerve injury.

Rubella virus tropism and single-cell responses in human primary tissue and microglia-containing organoids.

Rubella virus is an important human pathogen that can cause neurological deficits in a developing fetus when contracted during pregnancy. Despite successful vaccination programs in the Americas and many developed countries, rubella remains endemic in many regions worldwide and outbreaks occur wherever population immunity is insufficient. Intense interest since rubella virus was first isolated in 1962 has advanced our understanding of clinical outcomes after infection disrupts key processes of fetal neurodevelopment. Yet it is still largely unknown which cell types in the developing brain are targeted. We show that in human brain slices, rubella virus predominantly infects microglia. This infection occurs in a heterogeneous population but not in a highly microglia-enriched monoculture in the absence of other cell types. By using an organoid-microglia model, we further demonstrate that rubella virus infection leads to a profound interferon response in non-microglial cells, including neurons and neural progenitor cells, and this response is attenuated by the presence of microglia.

Rubella virus tropism and single-cell responses in human primary tissue and microglia-containing organoids

Rubella virus is an important human pathogen that can cause neurological deficits in a developing fetus when contracted during pregnancy. Despite successful vaccination programs in the Americas and many developed countries, rubella remains endemic in many regions worldwide and outbreaks occur wherever population immunity is insufficient. Intense interest since rubella virus was first isolated in 1962 has advanced our understanding of clinical outcomes after infection disrupts key processes of fetal neurodevelopment. Yet it is still largely unknown which cell types in the developing brain are targeted. We show that in human brain slices, rubella virus predominantly infects microglia. This infection occurs in a heterogeneous population but not in a highly microglia-enriched monoculture in the absence of other cell types. By using an organoid-microglia model, we further demonstrate that rubella virus infection leads to a profound interferon response in non-microglial cells, including neurons and neural progenitor cells, and this response is attenuated by the presence of microglia.

The use of a multicellular in vitro model to investigate uptake and migration of bacterial extracellular vesicles derived from the human gut commensal Bacteroides thetaiotaomicron

AbstractBacterial extracellular vesicles (BEVs) are increasingly seen as key signalling mediators between the gut microbiota and the host. Recent studies have provided evidence of BEVs ability to transmigrate across cellular barriers to elicit responses in other tissues, such as the central nervous system (CNS). Here we use a combination of single‐, two‐ and three‐cell culture systems to demonstrate the transmigration of Bacteroides thetaiotaomicron derived BEVs (Bt‐BEVs) across gut epithelium and blood brain barrier (BBB) endothelium, and their subsequent acquisition and downstream effects in neuronal cells. Bt‐BEVs were shown to traffic to the CNS in vivo after intravenous administration to mice, and in multi‐cell in vitro culture systems to transmigrate across gut epithelial and BBB endothelial cell barriers, where they were acquired by both microglia and immature neuronal cells. No significant activation/inflammatory effects were induced in non‐differentiated neurons, in contrast to that observed in microglia cells, although this was notably less than that induced by lipopolysaccharide (LPS). Overall, our findings provide evidence for transmigration of Bt‐BEVs across gut‐epithelial and BBB endothelial cell barriers in vivo and in vitro, and their downstream responses in neural cells. This study sheds light onto how commensal bacteria‐derived BEV transport across the gut‐brain axis and can be exploited for the development of targeted drug delivery.

Effects of acute low-moderate dose ionizing radiation to human brain organoids.

Human exposure to low-to-moderate dose ionizing radiation (LMD-IR) is increasing via environmental, medical, occupational sources. Acute exposure to LMD-IR can cause subclinical damage to cells, resulting in altered gene expression and cellular function within the human brain. It has been difficult to identify diagnostic and predictive biomarkers of exposure using traditional research models due to factors including lack of 3D structure in monolayer cell cultures, limited ability of animal models to accurately predict human responses, and technical limitations of studying functional human brain tissue. To address this gap, we generated brain/cerebral organoids from human induced pluripotent stem cells to study the radiosensitivity of human brain cells, including neurons, astrocytes, and oligodendrocytes. While organoids have become popular models for studying brain physiology and pathology, there is little evidence to confirm that exposing brain organoids to LMD-IR will recapitulate previous in vitro and in vivo observations. We hypothesized that exposing brain organoids to proton radiation would (1) cause a time- and dose-dependent increase in DNA damage, (2) induce cell type-specific differences in radiosensitivity, and (3) increase expression of oxidative stress and DNA damage response genes. Organoids were exposed to 0.5 or 2 Gy of 250 MeV protons and samples were collected at 30 minute, 24 hour, and 48 hour timepoints. Using immunofluorescence and RNA sequencing, we found time- and dose-dependent increases in DNA damage in irradiated organoids; no changes in cell populations for neurons, oligodendrocytes, and astrocytes by 24 hours; decreased expression of genes related to oligodendrocyte lineage, astrocyte lineage, mitochondrial function, and cell cycle progression by 48 hours; increased expression of genes related to neuron lineage, oxidative stress, and DNA damage checkpoint regulation by 48 hours. Our findings demonstrate the possibility of using organoids to characterize cell-specific radiosensitivity and early radiation-induced gene expression changes within the human brain, providing new avenues for further study of the mechanisms underlying acute neural cell responses to IR exposure at low-to-moderate doses.

Responses of Neural Cells (U87) to HCoV-229E and HCoV-OC43 Infections

Responses of Neural Cells (U87) to HCoV-229E and HCoV-OC43 Infections

Placenta-on-a-chip: Response of neural cells to pharmaceutical agents transported across the placental barrier

Striving for sustainable drug discovery, we have presented a proof-of-concept for studying the effects of pharmaceutical agents transported across the placental barrier on neural cells. The potential effects of pharmaceutical agents on fetus have made concerns about their use and require more studies to address these concerns. A placenta-on-a-chip model was fabricated and tested for transport of naltrexone (NTX) and its primary metabolite 6[Formula: see text]-naltrexol. The NTX/6[Formula: see text]-naltrexol transported from the maternal channel to the fetal channel was then collected from the fetal channel. To evaluate the behavior of neural cells following exposure to NTX and 6[Formula: see text]-naltrexol, perfusate from the fetal channel was directed toward the cultured N27 neural cells. Neural cells exposed to the transported NTX/6[Formula: see text]-naltrexol were then evaluated for gene expression and cell viability. Results showed significantly higher fold changes in IL-6 and TNF-[Formula: see text] expression when exposed to NTX/6[Formula: see text]-naltrexol. However, a lower fold change in IL-1[Formula: see text] expression was observed, while it remained the same in sphingosine kinase (sphk)1. Also, cell viability with NTX/6[Formula: see text]-naltrexol exposure was determined to be significantly lower ([Formula: see text]). This study has the potential to reveal the impact of pharmaceutical agents on the developing neural system of fetuses and their premature brains.

Early Responses of Neural Cells (U87) to Particulate Matter Exposure: Cell Viability and Cytokine Concentration

Particulate Matter (PM) has a significant impact on human health and increases the risk of respiratory diseases. PM exposure is linked to various illnesses, including cardiovascular diseases, cancer, neurological diseases, and pregnancy complications, and contributes to both mortality and morbidity globally. PM can also influence the autonomic nervous system. The evidence suggests that the likelihood of developing lung cancer continually rises with the rise in the concentration of coarse PM10 (medium aerodynamic diameter less than or equal to 10 μm). However, studies examining the relationship between PM10 exposure and brain cancer or gliomas are scarce. In this study, U87 cells were exposed to PM10 at three different concentrations and the effects were evaluated by analyzing Lactate Dehydrogenase (LDH) activity, Interleukin-6 (IL-6) expression, and cell viability using a water-soluble tetrazolium assay. The IL-6 concentration in U87 cells varied with PM10 concentration and exposure time. PM10 did not influence LDH activity in U87 cells at the tested concentrations. These results provide crucial information for future research aimed at understanding the impact of PM on human disease pathology.

EP-273 Magnetic nanoparticle administration to a model of penetrating neurotrauma in vitro

Abstract Introduction/Aims Functional recovery in penetrating traumatic brain injury (pTBI) is hampered due to the lack of clinically approved regenerative therapies. Although a surgical emergency, pTBI management is largely supportive, with no targeted neuroregenerative therapies. Reactive gliotic and neuroinflammatory responses with a lack of spontaneous axonal regeneration represent a major barrier to repair. Emergent nanotechnologies including magnetic nanoparticles (MNPs) show promise to attenuate such responses through immunomodulation, with potential of delivery of neurotherapeutic molecules to lesion sites during surgical intervention. However, there is a lack of high throughput, neuropathomimetic, models for nano/biomaterial testing in experimental neurology. Our group recently showed glial cell interactions with a surgical biomaterial scaffold (DuraGen PlusTM) in a novel in vitro model of pTBI. Methods Mice cerebral cortices were extracted and cultured 8–10 days in vitro (DIV) using previous methodology (Basit et al, Mat Sci Eng C, 2021) with a modified chemical medium. At 8 DIV, a sterile pipette was used for transection of the culture simulating penetrating injury in vitro with injection of carboxymethyl dextran-coated magnetic nanoparticles and polyethylene glycol-coated magnetic nanoparticles into the lesion site. MNP-neural cell responses were evaluated using immunocytochemistry methods. Results Our model demonstrates hallmark reactive gliotic responses, immune cell infiltration and axonal transection in injury sites. We demonstrate preferential and competitive microglial uptake of delivered MNPs versus other neural cell types (p<0.05, n=5). Conclusion The model is adaptable to study neural cell responses to range of materials, offering high versatility for testing promising surgical neuromaterial based therapeutic interventions in experimental clinically relevant research.

Multiscale approach for tFUS neurocomputational modelling.

Among the non-invasive methods employed for brain stimulation, trans cranial Focused Ultrasound Stimulation (tFUS) is the technique with the best penetration into the tissues and spatial resolution. The development of computational models of US propagation in brain tissue can be useful for estimating the behaviour of neural cells subjected to mechanical stimulus due to US. This paper aims at studying the neural cell response of a cortical Regular Spiking point neuron model, for different values of stimulus Duty Cycle (DC). The main goal is to use a multiscale approach to couple the results obtained from a macroscale simulation on wave propagation in tissue, with neuron model described by Hodgkin-Huxley equations to study latency and firing rate of the RS model. The obtained results showed that latency and firing rate have slight variations along the propagation direction of the US beam, in the focal region under the skull model, for different stimulus DC.