Sequential two-stage cultivation system using novel microalga consortia for treatment of municipal wastewater and simultaneous biomass production: Sustainable environmental management.

Monoculture-based microalgae cultivation systems to treat wastewater are well-reported. Despite that, this method has some limitations in terms of nutrient removal potential, environment adaptation, and low biomass productivity. Conversely, microalgae co-cultivation and a two-stage sequential cultivation system (TSSCS) recently emerged as a promising approach to improve the treatment process and biomass productivity through better adaptation to the environment. However, no outdoor large-scale experiments were reported using this approach which hinders the viability of the process. Thus, in the present study, a sequential two-stage large-scale outdoor novel microalgae consortia experiment was developed. In first stage consortia-assisted sequential cultivation, two ratios of Tetraselmis indica (TS) and one ratio of Picochlorum sp. (PC) (2 TS:1 PC) were cultivated in a 1000-L pond containing 75%-municipal wastewater (MWW) + 25%-ASN-III, while in the second stage, 2 PC:1 TS was cultivated in two different ponds, and each containing 375-L 2 TS:1 PC-treated water + 375-L ASN-III. Outdoor parameters and nutrient removal efficiency (NRE), biomass, and biomolecule productivity such as lipid, photosynthetic pigments, astaxanthin, and ß-carotene were quantified, and cost analysis was performed. At the end of the first and second stages, 2 TS:1 PC and 2 PC:1 TS showed maximum NRE of COD (68.71 and 86.40%), TN (66.98 and 94.73%), and TP (82.70 and 94.36%), respectively. Moreover, 2 TS:1 PC and 2 PC:1 TS Pond 1 and 2 produced maximum dry biomass production; 2.41 and ∼2.54 g/L contained lipid content; 36.89 and 34.90% that have 86.50 and 55.79% FAME content respectively. Similarly, 2 TS:1 PC and 2 PC:1 TS biomass exhibited valuable pigments production of astaxanthin i.e., 0.56 and 0.35 mg/g, and ß-carotene; 4.65 and 2.82 mg/g, respectively. The cost analysis suggested that only microalgal-based MWW treatment was unfeasible, while valorization of produced biomass into co-products could offset the operation costs and could allow the option for the microalgal-based sustainable approach for the treatment of MWW and recovery of valuable resources.

Isolation and characterization of native antagonistic rhizobacteria against Fusarium wilt of chilli to promote plant growth.

In the eastern coastal regions of Odisha, wilt caused by Fusarium oxysporum f. sp.capsici is an extremely damaging disease in chilli. This disease is very difficult to manage with chemical fungicides since it is soil-borne in nature. The natural rhizosphere soil of the chilli plant was used to isolate and test bacterial antagonists for their effectiveness and ability to promote plant growth. Out of the fifty-five isolates isolated from the rhizosphere of healthy chilli plants, five isolates, namely Iso 01, Iso 17, Iso 23, Iso 24, and Iso 32, showed their highly antagonistic activity against F. oxysporum f. sp. capsici under in vitro. In a dual culture, Iso 32 (73.3%) and Iso 24 (71.5%) caused the highest level of pathogen inhibition. In greenhouse trials, artificially inoculated chilli plants treated with Iso 32 (8.8%) and Iso 24 (10.2%) had decreased percent disease incidence (PDI), with percent disease reduction over control of 85.6% and 83.3%, respectively. Iso 32 and Iso 24 treated chilli seeds have shown higher seed vigor index of 973.7 and 948.8, respectively, as compared to untreated control 636.5. Furthermore, both the isolates significantly increased plant height as well as the fresh and dry weight of chilli plants under the rolled paper towel method. Morphological, biochemical, and molecular characterization identified Bacillus amyloliquefaciens (MH491049) as the key antagonist. This study demonstrates that rhizobacteria, specifically Iso 32 and Iso 24, can effectively protect chilli plants against Fusarium wilt while promoting overall plant development. These findings hold promise for sustainable and eco-friendly management of Fusarium wilt in chilli cultivation.

Obesity is associated with adverse outcomes in primary immune thrombocytopenia - a retrospective single-center study.

The pathophysiology of immune thrombocytopenia (ITP) involves immune-mediated platelet destruction. The presence of adipose tissue in obese individuals creates an inflammatory environment that could potentially impact the clinical course and outcomes of ITP. However the relationship between obesity and ITP outcomes has not been well described. We evaluated ITP outcomes in 275 patients diagnosed with primary ITP from 2012 to 2022. Patients were categorized into four groups based on their body mass index (BMI) at diagnosis. Female gender was associated with a lower platelet count at the time of diagnosis at any BMI. Patients with high BMI had lower platelet counts at diagnosis and at platelet nadir (p < 0.001), an increased likelihood of requiring therapy (p < 0.001) and requiring multiple lines of therapy (p = 0.032). Non-obese patients who required corticosteroid treatment experienced a longer remission duration compared to obese patients (p = 0.009) and were less likely to be steroid-dependent (p = 0.048). Our findings suggest that obesity may be a significant risk factor for developing ITP and for ITP prognosis. Future studies are needed to evaluate the role of weight loss intervention in improving ITP outcomes.

Unveiling the Rarity: A Fascinating Case of Chondro-Osseous Respiratory Epithelial Adenomatoid Hamartoma (COREAH) in the Sinonasal Tract.

Chondro-osseous respiratory adenomatoid hamartoma (COREAH) are extremely rare benign lesions of the sinonasal tract. It is present in 3 to 83-year-olds. It originates from various sites of the sinonasal tract; the most common site is the posterior lateral wall of the nasal cavity. Imaging calcification is an important finding in COREAH. In this case report, we present an exceptionally rare occurrence involving a 55-year-old female patient who exhibited symptoms of nasal obstruction, bleeding from the left side of the nasal cavity and loss of smell. We aim to share our experience in managing this unique condition. Diagnostic nasal endoscopic examination of the patient revealed a reddish, fleshy polypoidal mass in the left nasal cavity arising from the lateral wall of the left nasal cavity posteriorly and extending anteriorly into the left nasal cavity. The patient underwent an excisional biopsy. Upon microscopic examination, we observed a hamartomatous proliferation of respiratory-type glands exhibiting mucinous metaplasia. Additionally, numerous spicules of mature bone were present, a distinctive feature of COREAH. The patient underwent a 6-month follow-up, during which no recurrent growth was detected within the nasal cavity.

Sublingual Space Schwannoma: An Uncommon Tumour in a Unique Anatomical Location.

A Schwannoma is a benign tumour originating from Schwann cells within the peripheral, cranial, or autonomic nerves. Typically, these tumours manifest as a solitary, slow-growing mass with smooth surface, usually devoid of significant symptoms. Schwannomas most frequently appear in individuals aged 30-50 years. Although they are relatively uncommon, approximately one-fourth of all Schwannomas are found in the head and neck area. Its occurrence within the oral cavity, with the tongue being the most common site, followed by the palate, floor of the mouth, buccal mucosa, lips, and jaws. Diagnosing these tumours before surgery can be challenging, and in most instances, a definitive diagnosis can only be established through surgical intervention and subsequent histological examination. Immunohistochemistry plays a crucial role in confirming the diagnosis, as it shows that Schwannoma cells exhibit a positive reaction to the S-100 protein. Here, we present a case of a Schwannoma in the floor of the mouth, observed in an 18-year-old male patient.

Biological encirclage-Traboulsi syndrome.

BACKGROUND: Traboulsi syndrome is a sporadic autosomal recessive disorder. Very few cases reported and no surgical treatment has been described. PURPOSE: The purpose of the study was to describe the surgical treatment of a case of Traboulsi syndrome with intercalary staphyloma. SYNOPSIS: Traboulsi syndrome[1-3] is a type of spontaneous filtering bleb. The case was of a 31-year-old lady with a flat anterior chamber and large intercalary staphyloma, with a subluxated clear lens. Liberal peritomy was done. The staphyloma was cut and the displaced lens was delivered through it. It was closed with 7-0 vicryl continuous suture. A cross-linked cornea was used after removing the Descemet membrane. It was modified to match the crescentic shape of the limbus by using 11 and 6 mm trephine. Two wedge-shaped defects were created and tissue was excised between them, which were then sutured to increase the arc radius. A peripheral flange at the corneal edge was created. A pocket was created in the host cornea to accommodate the donor corneal flange. The donor cornea was tucked in and the graft was sutured. The sclera was used to suture another side prophylactically, making a 360-degree encirclage. The patient got ambulatory vision postsurgery. The use of the cornea as biological encirclage has not been described previously. HIGHLIGHTS: Using a cross-linked cornea. Creating wedge-shaped defects in crescentic corneal graft to increase arc radius. Use of cornea as encirclage.Link of video:https://youtu.be/T3b5rkvFmlc.

A One-Pot Cascade Strategy toward Organocatalytic Enantioselective Construction of Fused Benzimidazoles.

Herein, we describe an asymmetric assembly of ortho-aromatic diamines and formyl tethered Michael acceptors forming chiral fused benzimidazoles. A cinchona-alkaloid-derived bifunctional squaramide catalyst enables the methodology through on-site dihydrobenzimidazole formation followed by an aza-Michael addition/oxidation cascade. This protocol stands out for its excellent catalytic efficiency over the background reaction and its mild conditions, making it more practical. Various Michael acceptors, including enones, ester, and thioester, were successful substrates in this study. Additionally, this methodology has demonstrated scalability and successfully showcased postsynthetic transformations.

Recent Advances in Targeting Transition Metals (Copper, Iron, and Zinc) in Alzheimer's Disease.

Changes in the transition metal homeostasis in the brain are closely linked with Alzheimer's disease (AD), including intraneuronal iron accumulation and extracellular copper and zinc pooling in the amyloid plague. The brain copper, zinc, and iron surplus are commonly acknowledged characteristics of AD, despite disagreements among some. This has led to the theory that oxidative stress resulting from abnormal homeostasis of these transition metals may be a causative explanation behind AD. In the nervous system, the interaction of metals with proteins appears to be an essential variable in the development or suppression of neurodegeneration. Chelation treatment may be an option for treating neurodegeneration induced by transition metal ion dyshomeostasis. Some clinicians even recommend using chelating agents as an adjunct therapy for AD. The current review also looks at the therapeutic strategies that have been attempted, primarily with metal-chelating drugs. Metal buildup in the nervous system, as reported in the AD, could be the result of compensatory mechanisms designed to improve metal availability for physiological functions.

Association between baseline insulin resistance and hospital mortality in moderate-to-severe coronavirus disease 2019 patients without diabetes mellitus: An observational study.

Background: Insulin resistance is often implicated as a risk factor of cell-mediated immune dysfunction in sepsis patients and results in poor clinical outcome. However, it is unclear whether early insulin resistance is contributory to T-cell dysfunction and poor clinical outcome in coronavirus disease 2019 (COVID-19) patients. Methods: Adult patients with moderate-to-severe or critically ill COVID-19 infection were included in this study. Serum samples were collected at the time of diagnosis for fasting plasma glucose, serum insulin, serum cortisol, and serum glucagon measurements, and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) score was calculated. Results: One hundred and twenty-six subjects with a mean (standard deviation) age of 49.6 (16.3) years were recruited in this study, and 62.4% (78 of 125 patients) were male. HOMA-IR was a predictor of inhospital mortality with the area under the receiver operating characteristics curve (AUROC) (95% confidence interval [CI] of 0.61 [0.49-0.73]). With a cutoff value of 1.91, sensitivity was 75.5% and specificity was 45.2%. Higher serum insulin was associated with higher survival with AUROC (95% CI) of 0.65 (0.53-0.76), and the best cutoff was 7.15, with a sensitivity and specificity of 62.1% and 64.5%. Serum cortisol was also a predictor of inhospital mortality with an AUROC (95% CI) of 0.67 (0.56-0.77). Conclusion: An independent association between baseline serum cortisol and poor outcome in moderate-to-severe COVID-19 patients was observed. Hyperglycemia and HOMA-IR can also predict poor outcome in these patients with some accuracy.

A study on expression of programmed death ligand-1 in small cell lung carcinoma and correlation with clinicopathological parameters.

Small cell lung carcinoma (SCLC) is characterized by rapid growth and an aggressive clinical course. Standard therapy regimes have limited effects on disease course; therefore the prognosis of SCLC is poor. In the current study, the frequency of programmed death ligand 1 (PD-L1) expression in SCLC and its correlation with clinico-pathological features were evaluated. The study included 100 cases of SCLC wherein testing for PD-L1 was done with the SP263 clone on the Ventana benchmark XT system. Cases with > 1% PD-L1 expression in tumour cells or immune cells were categorized as positive. PD-L1 expression was identified in 14% of cases using the cut-off of ≥ 1%. The tumour proportion score was 10% and the immune proportion score was 9.78% using a cut-off of ≥ 1%. PD-L1 positive expression was more frequent in the male population with age > 40 years. All the patients with positive PD-L1 expression were smokers. In the PD-L1 positive group, presence of necrosis was identified in 71.4% of cases and when compared with the PD-L1 negative subgroup this finding was statistically significant (p = 0.010). Personalized targeted therapy for cases of SCLC is still under evaluation. The use of immunotherapeutic targets, such as PD-L1, may help to define a new treatment strategy for SCLC. Development of new treatment strategies may improve prognosis and survival.

A Digermanium(III) 1,2-Dication Stabilized by Amidinate and cAAC-Phosphinidenide Ligands.

A digermanium(III) 1,2-dication comprises two cationic centers located at two interconnected Ge atoms. The strong Coulombic repulsion between two positively charged germanium cations hinders their bond formation. Balancing these two oppositions was achieved by using amidinate and cyclic (alkyl)amino carbene (cAAC)-phosphinidenide ligands, where an amidinato cAAC-phosphinidenidogermylene complex, [LGeP(cAACMe)] (2, where L = PhC(NtBu)2, cAACMe = :C{C(Me)2CH2C(Me)2NAr}, and Ar = 2,6-iPr2C6H3), underwent one-electron oxidation with a bis(phosphinidene) radical cation, [(cAACMe)P]2•+, to form a digermanium(III) 1,2-dication, [LGeP(cAACMe)]22+, in compound 4.

Mitigating postharvest quantitative and qualitative losses in mango fruits through the application of biocontrol agents: An in-vivo and in-vitro assessment.

Mango is a commercial fruit crop of India that suffers huge postharvest losses every year. The application of biocontrol agents (BCAs) bears a vast potential for managing the same, which is yet to be exploited to its fullest extent. Hence, studies were conducted for BCAs application of Debaryomyces hansenii, Bacillus subtilis and Pseudomonas fluorescens strains on mango fruit under in-vitro, in-vivo conditions to know the efficacy of these BCAs on the postharvest pathogen, shelf life and quality retention of mango fruit. The 'poisoned food technique' was attempted for in-vitro studies. For the in-vivo studies, fruit of the commercial cultivar 'Amrapali' were un-inoculated and pre-inoculated with major postharvest pathogens (anthracnose: Colletotrichum gloeosporioides and stem-end rot: Botryodiplodia theobromae) were treated with BCA, followed by ambient storage at (24 ± 4 °C, 75 ± 5 % RH). From the results, it has been observed that under in vitro studies, BCA Debaryomyces hansenii (Strain: KP006) and Bacillus subtilis (Strain: BJ0011) at the treatment level 108 CFU mL-1 while, the Pseudomonas fluorescens at 109 CFU mL-1 (Strain: BE0001) were significantly effective for pathogen inhibition. However, under the in vivo studies, the BCA Debaryomyces hansenii (Strain: KP006) at 108 CFU mL-1 treatment level was found to significantly reduce the pathogen's decay incidence while positively influencing the shelf life and biochemical (quality) attributes. This treatment increased the storage life of mango fruit by more than three days over control fruit. Therefore, BCA Debaryomyces hansenii (Strain: KP006) at 108 CFU mL-1 can be used to control the postharvest pathological loss of mango fruit without affecting its internal quality.

I2-Mediated Site-Selective C-H Functionalization: Access to p-Amino-Substituted Unsymmetrical Benzils and Quinoxalines from Sulfoxonium Ylides.

An I2-mediated approach for selective C-H functionalization of unprotected aniline derivatives for synthesizing benzils and quinoxaline derivatives from sulfoxonium ylides has been described. Aniline derivatives and sulfoxonium ylides ornamented with different functional groups showed good compatibility. They afforded the corresponding products with moderate to high yields via a mild and simple procedure. Finally, we validated the practicality of this method by scaling up the reaction and further conversion of the synthesized derivatives into other valuable molecules.

Novel genetic association of the Furin gene polymorphism rs1981458 with COVID-19 severity among Indian populations.

SARS CoV-2, the causative agent for the ongoing COVID-19 pandemic, it enters the host cell by activating the ACE2 receptor with the help of two proteasesi.e., Furin and TMPRSS2. Therefore, variations in these genes may account for differential susceptibility and severity between populations. Previous studies have shown that the role of ACE2 and TMPRSS2 gene variants in understanding COVID-19 susceptibility among Indian populations. Nevertheless, a knowledge gap exists concerning the COVID-19 susceptibility of Furin gene variants among diverse South Asian ethnic groups. Investigating the role of Furin gene variants and their global phylogeographic structure is essential to comprehensively understanding COVID-19 susceptibility in these populations. We have used 450 samples from diverse Indian states and performed linear regression to analyse the Furin gene variant's with COVID-19 Case Fatality Rate (CFR) that could be epidemiologically associated with disease severity outcomes. Associated genetic variants were further evaluated for their expression and regulatory potential through various Insilco analyses. Additionally, we examined the Furin gene using next-generation sequencing (NGS) data from 393 diverse global samples, with a particular emphasis on South Asia, to investigate its Phylogeographic structure among diverse world populations. We found a significant positive association for the SNP rs1981458 with COVID-19 CFR (p < 0.05) among diverse Indian populations at different timelines of the first and second waves. Further, QTL and other regulatory analyses showed various significant associations for positive regulatory roles of rs1981458 and Furin gene, mainly in Immune cells and virus infection process, highlighting their role in host immunity and viral assembly and processing. The Furin protein-protein interaction suggested that COVID-19 may contribute to Pulmonary arterial hypertension via a typical inflammation mechanism. The phylogeographic architecture of the Furin gene demonstrated a closer genetic affinity of South Asia with West Eurasian populations. Therefore, it is worth proposing that for the Furin gene, the COVID-19 susceptibility of South Asians will be more similar to the West Eurasian population. Our previous studies on the ACE2 and TMPRSS2 genes showed genetic affinity of South Asian with East Eurasians and West Eurasians, respectively. Therefore, with the collective information from these three important genes (ACE2, TMPRSS2 and Furin) we modelled COVID-19 susceptibilityof South Asia in between these two major ancestries with an inclination towards West Eurasia. In conclusion, this study, for the first time, concluded the role of rs1981458 in COVID-19 severity among the Indian population and outlined its regulatory potential.This study also highlights that the genetic structure for COVID-19 susceptibilityof South Asia is distinct, however, inclined to the West Eurasian population. We believe this insight may be utilised as a genetic biomarker to identify vulnerable populations, which might be directly relevant for developing policies and allocating resources more effectively during an epidemic.

Self-actuating inflammation responsive hydrogel microsphere formulation for controlled drug release in rheumatoid arthritis (RA): Animal trials and study in human fibroblast like synoviocytes (hFLS) of RA patients.

Patients with rheumatoid arthritis (RA) often have one or more painfuljoints despite adequate medicine. Local drug delivery to the synovial cavity bids for high drug concentration with minimal systemic adverse effects. However, anti-RA drugs show short half-lives in inflamed joints after intra-articular delivery. To improve the therapeutic efficacy, it is essential to ensure that a drug is only released from the formulation when it is needed. In this work, we developed an intelligent "Self-actuating" drug delivery system where Disease-modifying anti-rheumatic Drug (DMARD) methotrexate is incorporated within a matrix intended to be injected directly into joints. This formulation has the property to sense the need and release medication only when joints are inflamed in response to inflammatory enzyme Matrix metalloproteinases (MMP). These enzymes are important proteases in RA pathology, and several MMP are present in augmented levels in synovial fluid and tissues. A high level of MMP present in synovial tissues of RA patients would facilitate the release of drugs in response and ascertain controlled drug release. The formulation is designed to be stable within the joint environment, but to dis-assemble in response to inflammation. The synthesized enzyme-responsive methotrexate (Mtx) encapsulated micron-sized polymer-lipid hybrid hydrogel microspheres (Mtx-PLHM) was physiochemically characterized and tested in synovial fluid, Human Fibroblast like synoviocytes (h-FLS) (derived from RA patients) and a rat arthritic animal model. Mtx-PLHM can self-actuate and augment the release of Mtx drug upon contact with either exogenously added MMP or endogenous MMP present in the synovial fluid of patients with RA. The drug release from the prepared formulation is significantly amplified to several folds in the presence of MMP-2 and MMP-9 enzymes. In the rat arthritic model, Mtx-PLHM showed promising therapeutic results with the significant alleviation of RA symptoms through decrease in joint inflammation, swelling, bone erosion, and joint damage examined by X-ray analysis, histopathology and immune-histology. This drug delivery system would be nontoxic as it releases more drug only during the period of exacerbation of inflammation. This will simultaneously protect patients from unwanted side effects when the disease is inactive and lower the need for repeated joint injections.

Comparison of Different Endodontic Access Cavity Designs on the Fracture Resistance of Tooth in WaveOne Gold and TruNatomy Instrumentation.

Background: An important aspect of the preparation of the access cavity and biomechanical preparation of the root canal is to safeguard as much of the tooth's framework as possible without affecting access and visibility. Objectives: To compare the impact of the conservative design of access preparation and traditional design of access preparation in association with TruNatomy endodontic instrumentation and WaveOne Gold endodontic instrumentation on resistance to fracture by the design of a cavity for endodontic access using finite element analysis. Materials and Methods: Micro-CT radiographic images of 16 human first permanent molars of the mandible were included in the study to create representative finite element analysis computational models. Results: A significant reduction in load for failure after endodontic preparation was observed in TDAP subcategories as compared to specimens with CDAP. However, the reduction in load for failure was comparable in both endodontic instrument systems within the CDAP and TDAP. Conclusion: A significant reduction in load for failure after endodontic preparation was observed in the traditional design of access preparation subcategories as compared to specimens with the conventional design of access preparation.

Advances in Lingual Thyroid Management Using Coblation Technology: A Case Series Study.

Lingual thyroid is a rare, abnormal ectopic thyroid tissue seen at the base of the tongue. It is a rare embryological anomaly caused by the failure of the descendence of the thyroid gland from the foramen caecum to its normal prelaryngeal area. The main aim of our study is to discuss recent advancements in the management of lingual thyroid using coblation technology. We are discussing the prospective study of 12 lingual thyroid cases that came to the government ENT hospital, Koti, in Hyderabad, from July 2016 to July 2023. All patients were assessed by a detailed history, blood investigations, fine needle aspiration cytology, radiological investigations, technetium-99 scintigraphy, and an endocrinologist opinion. In our study, all cases were hypothyroid and showed difficulty in swallowing and a few cases showed bleeding from the mouth, and difficulty in breathing, hence all 12 cases underwent coblation-assisted excision of swelling and with lifelong thyroxine supplementation. For all 12 cases, demographic, clinicopathological data and radiological data were recorded. Treatment depends on the age of the patient, the severity of symptoms, precipitating factors like puberty or pregnancy, or any other comorbidities with the disease. In our study, all cases were symptomatic and hypothyroid status, hence all 12 cases underwent coblation-assisted excision of swelling and lifelong thyroxine supplementation. All cases were followed up for 2 years with good recovery, minimal patient discomfort after surgery, and lifelong levothyroxine supplementation. Lingual thyroids have a female preponderance. In our study, all were female. Thyroid scintigraphy plays an important role in diagnosis, along with ultrasonography. In all symptomatic cases, surgery with Coblation-assisted excision of swelling is the treatment of choice, with good recovery, minimal patient discomfort after surgery and with lifelong levothyroxine supplementation.

Angiolymphoid Hyperplasia with Eosinophilia of the External Auditory Canal.

Angiolymphoid hyperplasia with eosinophilia is a rare, benign, vaso-proliferative disease with a dense eosinophilic inflammatory infiltrate seen in the intradermal or subcutaneous region. It is also termed an epitheloid hemangioma, and it mostly affects females rather than males. It is seen as reddish to brown, fleshy, proliferative, papular, or nodular lesion affecting the head and neck region, most commonly the auricular and periauricular regions. The aetiology is unknown, but the most likely causes are trauma, infection, and hyperestrogenic condition like pregnancy or the use of oral contraceptive agents. It usually measures about 2-3 cm in size. It should be differentiated from Kimura disease, which is characterized by chronic inflammation and large subcutaneous nodules in the head and neck region. Here is a rare case report of angiolymphoid hyperplasia in a middle-aged male patient involving the external auditory canal of the left ear.

Dendritic effects of tDCS insights from a morphologically realistic model neuron.

Transcranial direct current stimulation (tDCS) induces subcellular compartmental-dependent polarization, maximal in the distal portions of axons and dendrites. Using a morphologically realistic neuron model, we simulated tDCS-induced membrane polarization of the apical dendrite. Thus, we investigated the differential dendritic effects of anodal and cathodal tDCS on membrane potential polarization along the dendritic structure and its subsequent effects on dendritic membrane resistance, excitatory postsynaptic potential amplitude, backpropagating action potential amplitude, input/output relations, and long-term synaptic plasticity. We further showed that the effects of anodal and cathodal tDCS on the backpropagating action potential were asymmetric, and explained this asymmetry. Additionally, we showed that the effects on input/output relations were rather weak and limited to the low-mid range of stimulation frequencies, and that synaptic plasticity effects were mostly limited to the distal portion of the dendrite. Thus, we demonstrated how tDCS modifies dendritic physiology due to the dendrite's unique morphology and composition of voltage-gated ion channels.