Generation of Functional Human 3D Cortico-Motor Assembloids.

Neurons in the cerebral cortex connect through descending pathways to hindbrain and spinal cord to activate muscle and generate movement. Although components of this pathway have been previously generated and studied in vitro, the assembly of this multi-synaptic circuit has not yet been achieved with human cells. Here, we derive organoids resembling the cerebral cortex or the hindbrain/spinal cord and assemble them with human skeletal muscle spheroids to generate 3D cortico-motor assembloids. Using rabies tracing, calcium imaging, and patch-clamp recordings, we show that corticofugal neurons project and connect with spinal spheroids, while spinal-derived motor neurons connect with muscle. Glutamate uncaging or optogenetic stimulation of cortical spheroids triggers robust contraction of 3D muscle, and assembloids are morphologically and functionally intact for up to 10 weeks post-fusion. Together, this system highlights the remarkable self-assembly capacity of 3D cultures to form functional circuits that could be used to understand development and disease.

Primate cell fusion disentangles gene regulatory divergence in neurodevelopment.

Among primates, humans display a unique trajectory of development that is responsible for the many traits specific to our species. However, the inaccessibility of primary human and chimpanzee tissues has limited our ability to study human evolution. Comparative in vitro approaches using primate-derived induced pluripotent stem cells have begun to reveal species differences on the cellular and molecular levels1,2. In particular, brain organoids have emerged as a promising platform to study primate neural development in vitro3-5, although cross-species comparisons of organoids are complicated by differences in developmental timing and variability of differentiation6,7. Here we develop a new platform to address these limitations by fusing human and chimpanzee induced pluripotent stem cells to generate a panel of tetraploid hybrid stem cells. We applied this approach to study species divergence in cerebral cortical development by differentiating these cells into neural organoids. We found that hybrid organoids provide a controlled system for disentangling cis- and trans-acting gene-expression divergence across cell types and developmental stages, revealing a signature of selection on astrocyte-related genes. In addition, we identified an upregulation of the human somatostatin receptor 2 gene (SSTR2), which regulates neuronal calcium signalling and is associated with neuropsychiatric disorders8,9. We reveal a human-specific response to modulation of SSTR2 function in cortical neurons, underscoring the potential of this platform for elucidating the molecular basis of human evolution.

Impact of severe acute kidney injury on short-term mortality in urosepsis.

PURPOSE: To evaluate the impact of severe acute kidney injury (AKI) on short-term mortality in patients with urosepsis. METHODS: This prospective cohort study evaluated 207 patients with urosepsis. AKI was diagnosed in accordance with the Kidney Disease Improving Global Outcomes criteria, and severe AKI was defined as stage 2 or 3 AKI. Patients were divided into two groups: patients who developed severe AKI (severe AKI group) and patients who did not (control group). The primary endpoint was all-cause mortality within 30 days. The secondary endpoints were 90-day mortality and in-hospital mortality. The exploratory outcomes were the risk factors for severe AKI development. RESULTS: The median patient age was 79 years. Of the 207 patients, 56 (27%) developed severe AKI. The 30-day mortality rate in the severe AKI group was significantly higher than that in the control group (20% vs. 2.0%, respectively; P < 0.001). In the multivariable analysis, performance status and severe AKI were significantly associated with 30-day mortality. The in-hospital mortality and 90-day mortality rates in the severe AKI group were significantly higher than those in the control group (P < 0.001 and P < 0.001, respectively). In the multivariable analysis, age, urolithiasis-related sepsis, lactate values, and disseminated intravascular coagulation were significantly associated with severe AKI development. CONCLUSIONS: Severe AKI was a common complication in patients with urosepsis and contributed to high short-term mortality rates.

Film measurement and analytical approach for assessing treatment accuracy and latency in a magnetic resonance-guided radiotherapy system.

PURPOSE: We measure the dose distribution of gated delivery for different target motions and estimate the gating latency in a magnetic resonance-guided radiotherapy (MRgRT) system. METHOD: The dose distribution accuracy of the gated MRgRT system (MRIdian, Viewray) was investigated using an in-house-developed phantom that was compatible with the magnetic field and gating method. This phantom contains a simulated tumor and a radiochromic film (EBT3, Ashland, Inc.). To investigate the effect of the number of beam switching and target velocity on the dose distribution, two types of target motions were applied. One is that the target was periodically moved at a constant velocity of 5 mm/s with different pause times (0, 1, 3, 10, and 20 s) between the motions. During different pause times, different numbers of beams were switched on/off. The other one is that the target was moved at velocities of 3, 5, 8, and 10 mm/s without any pause (i.e., continuous motion). The gated method was applied to these motions at MRIdian, and the dose distributions in each condition were measured using films. To investigate the relation between target motion and dose distribution in the gating method, we compared the results of the gamma analysis of the calculated and measured dose distributions. Moreover, we analytically estimated the gating latencies from the dose distributions measured using films and the gamma analysis results. RESULTS: The gamma pass rate linearly decreased with increasing beam switching and target velocity. The overall gating latencies of beam-hold and beam-on were 0.51 ± 0.17 and 0.35 ± 0.05 s, respectively. CONCLUSIONS: Film measurements highlighted the factors affecting the treatment accuracy of the gated MRgRT system. Our analytical approach, employing gamma analysis on films, can be used to estimate the overall latency of the gated MRgRT system.

Effect of upfront intensive therapy on oncological outcomes in older patients with high tumor burden metastatic castration-sensitive prostate cancer: A multicenter retrospective study.

BACKGROUND: The effect of upfront intensive therapy on the prognosis of older patients with metastatic castration-sensitive prostate cancer (mCSPC) remains unclear. Thus, we assessed the impact of older age (≥75 years) on oncological outcomes in mCSPC patients with a high tumor burden. METHODS: This multicenter retrospective study included 252 patients aged ≥75 years treated with either upfront or conventional therapy between 2014 and 2021. We compared castration-resistant prostate cancer (CRPC)-free survival (FS) and overall survival (OS) between patients with androgen deprivation therapy (ADT) plus upfront intensive therapy (docetaxel [DTX] or abiraterone acetate [ABI] plus prednisolone) and conventional therapy (ADT monotherapy or ADT combined with bicalutamide). We evaluated the effect of upfront intensive therapy on prognosis by multivariable Cox regression analysis. RESULTS: The 231 patients enrolled in our study were classified in the conventional group (n = 148) or the upfront group (n = 104; DTX = 27 and ABI = 77). The upfront group had significantly prolonged CRPC-FS and OS compared with the conventional group, and this was also the case in the background-adjusted multivariable Cox regression analysis. CONCLUSION: Patients aged ≥75 years who received upfront intensive therapy had significantly longer CRPC-FS and OS compared with similar age patients treated with conventional therapy in real-world practice. The oncological benefit may not diminish in this older population.

Reliability of human cortical organoid generation.

The differentiation of pluripotent stem cells in three-dimensional cultures can recapitulate key aspects of brain development, but protocols are prone to variable results. Here we differentiated multiple human pluripotent stem cell lines for over 100 d using our previously developed approach to generate brain-region-specific organoids called cortical spheroids and, using several assays, found that spheroid generation was highly reliable and consistent. We anticipate the use of this approach for large-scale differentiation experiments and disease modeling.

ERK5 inhibitor BIX02189 attenuates methamphetamine-induced hyperactivity by modulating microglial activation in the striatum.

Extracellular signal-regulated protein kinase 5 (ERK5) has various physiological functions. However, the physiological role of ERK5 in the treatment of mice with an illicit drug such as methamphetamine (METH) remains unknown. We revealed that mice treated with METH showed hyperactivity, and increased p-ERK5 and Iba1 (a microglia marker) levels in the striatum. Additionally, these changes were inhibited by pretreatment with the ERK5 inhibitor BIX02189. The results suggest that METH-induced hyperactivity is associated with the activation of microglia via p-ERK5 in the striatum. Thus, the ERK5 pathway components in the central nervous system are potential therapeutic targets for preventing METH addiction.

Safety and efficacy of atezolizumab plus bevacizumab in patients with unresectable hepatocellular carcinoma in early clinical practice: A multicenter analysis.

PURPOSE: To assess the impact of clinical factors on the safety and efficacy of atezolizumab plus bevacizumab (ATZ + BV) treatment in patients with unresectable hepatocellular carcinoma (u-HCC). METHOD: Ninety-four u-HCC patients who were treated with ATZ + BV at multiple centers were enrolled. We defined Child-Pugh (CP)-A patients who received ATZ + BV treatment as a first line therapy as the 'meets the broad sense of the IMbrave150 criteria' group (B-IMbrave150-in, n = 46), and patients who received ATZ + BV treatment as a later line therapy or CP-B patients (regardless of whether ATZ + BV was a first line or later line therapy) as the B-IMbrave150-out group (n = 48). Patients were retrospectively analyzed for adverse events (AEs) and treatment outcomes according to their clinical characteristics, including neutrophil lymphocyte ratio (NLR) at baseline. RESULTS: The overall incidence of AEs was 87.2% (82/94 patients). The frequency of interruption of ATZ + BV treatment due to fatigue was higher in CP-B than CP-A patients (p = 0.030). Objective response (OR) rates of the B-IMbrave150-in group (28.3%, 39.1%) were significantly higher than those of the B-IMbrave150-out group (8.3%, 18.8%; p = 0.0157, 0.0401) using Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST, respectively. In multivariate analysis, NLR (hazard ratio (HR), 4.591; p = 0.0160) and B-IMbrave150 criteria (HR, 4.108; p = 0.0261) were independent factors associated with the OR of ATZ + BV treatment using RECIST. CONCLUSION: In real-world practice, ATZ + BV treatment might offer significant benefits in patients who meet B-IMbrave150 criteria or have low NLR.

The efficacy of a third-generation oncolytic herpes simplex viral therapy for an HPV-related uterine cervical cancer model.

PURPOSE: Cervical cancer is the fourth most common cancer in women and the seventh most common of all human cancers. Development of new treatments is mandatory to improve the outcome of this disease. Replication-selective oncolytic herpes simplex viruses (HSVs) have emerged as a new platform for cancer therapy. The therapeutic potential of a triple-mutated oncolytic HSV (T-01) for human papillomavirus (HPV)-related cervical cancer was evaluated with immunodeficient and immune-complete models. METHODS: (1) The in vitro efficacy of T-01 on human cervical cancer cell lines, TC-1, HeLa, CaSki, and SKG IIIa was evaluated. (2) The in vivo efficacy of T-01 was examined in human HeLa xenograft and TC-1 syngeneic models of human cervical cancer. After flank tumors reached 5 mm in diameter, the first intratumoral (i.t.) administration of T-01 was performed. Intratumoral administration of T-01 was performed with a 5 day interval a total of 6 times. RESULTS: In the in vitro study, T-01 was highly cytotoxic for all cell lines (48 h after infection with T-01 at 1 × 105 PFU, T-01 killing HeLa: 67.5%, Caski: 62.8%, SKG IIIa: 43.2%). Furthermore, in the human HeLa xenograft and TC-1 syngeneic models, T-01 resulted in a significant reduction of tumor growth. In addition, tumor-bearing mice treated with T-01 showed significantly increased numbers of CD8 + T-cells precursors than the control mice (p = 0.03). CONCLUSIONS: These results demonstrate that T-01 has cytotoxic efficacy and inhibited against HPV-related cervical cancer cells. These findings indicate that T-01 has therapeutic potential for HPV-related cervical cancer.

Recurrent branch of anterior interosseous artery perforator-based propeller flap for distal forearm injuries: Report of 2 cases.

Despite various options for the reconstruction of soft tissue defects in the distal forearm, perforator-based propeller flap is rarely used. Here, we presented 2 cases of distal forearm injuries that were repaired using the recurrent branch of anterior interosseous artery perforator-based propeller flap. Patients in these cases were 57 and 67 years of age. Wounds resulting from farming machine injury and pyogenic extensor tenosynovitis following cat bite wounds were localized to the distal forearm and dorsum of the hand. Defect dimensions were 5 cm × 10 cm and 5 cm × 8 cm. The 12 cm × 7 cm and 21 cm × 4 cm sized recurrent branch of anterior interosseous artery perforator-based propeller flap was designed adjacent to the wounds. In the latter case, the absence of the posterior interosseous artery in the distal forearm was observed. One perforator from the recurrent branch of the anterior interosseous artery emerged through the septum between the extensor digiti minimi and extensor carpi ulnaris 7.5 cm and 6.0 cm proximal to the ulnar head in cases 1 and 2, respectively. Perforators were identified using multidetector computed tomographic angiography and handheld Doppler. Extending to two-thirds or almost the full length of the forearm, the flaps were raised and rotated by 90° and 120° to cover the defect. The donor sites were closed using free skin graft. Both flaps survived. Except for minor wound dehiscence and hemarthrosis, no other postoperative complications occurred. Patients returned to work or daily activities at 3- and 4-month follow-up after surgery.

ACAP3, the GTPase-activating protein specific to the small GTPase Arf6, regulates neuronal migration in the developing cerebral cortex.

The GTPase-activating protein (GAP) specific to the small GTPase Arf6, ACAP3, is known to regulate morphogenesis of neurons in vitro. However, physiological significance of ACAP3 in the brain development in vivo remains unclear. Here, we show that ACAP3 is involved in neuronal migration in the developing cerebral cortex of mice. Knockdown of ACAP3 in the developing cortical neurons of mice in utero significantly abrogated neuronal migration in the cortical layer, which was restored by ectopic expression of wild type of ACAP3, but not by its GAP-inactive mutant. Furthermore, morphological changes of neurons during migration in the cortical layer were impeded in ACAP3-knocked-down cortical neurons. These results provide evidence that ACAP3 plays a crucial role in migration of cortical neurons by regulating their morphological change during development of cerebral cortex.

ACAP3 regulates neurite outgrowth through its GAP activity specific to Arf6 in mouse hippocampal neurons.

ACAP3 (ArfGAP with coiled-coil, ankyrin repeat and pleckstrin homology domains 3) belongs to the ACAP family of GAPs (GTPase-activating proteins) for the small GTPase Arf (ADP-ribosylation factor). However, its specificity to Arf isoforms and physiological functions remain unclear. In the present study, we demonstrate that ACAP3 plays an important role in neurite outgrowth of mouse hippocampal neurons through its GAP activity specific to Arf6. In primary cultured mouse hippocampal neurons, knockdown of ACAP3 abrogated neurite outgrowth, which was rescued by ectopically expressed wild-type ACAP3, but not by its GAP activity-deficient mutant. Ectopically expressed ACAP3 in HEK (human embryonic kidney)-293T cells showed the GAP activity specific to Arf6. In support of this observation, the level of GTP-bound Arf6 was significantly increased by knockdown of ACAP3 in hippocampal neurons. In addition, knockdown and knockout of Arf6 in mouse hippocampal neurons suppressed neurite outgrowth. These results demonstrate that ACAP3 positively regulates neurite outgrowth through its GAP activity specific to Arf6. Furthermore, neurite outgrowth suppressed by ACAP3 knockdown was rescued by expression of a fast cycle mutant of Arf6 that spontaneously exchanges guanine nucleotides on Arf6, but not by that of wild-type, GTP- or GDP-locked mutant Arf6. Thus cycling between active and inactive forms of Arf6, which is precisely regulated by ACAP3 in concert with a guanine-nucleotide-exchange factor(s), seems to be required for neurite outgrowth of hippocampal neurons.

Epigenetic regulation of neural N-glycomics.

Glycan expression is tightly regulated in a cell-type-specific manner, which is essential for the diverse functions of glycans. In particular, neural cells such as neurons and astrocytes are known to express unique functional glycans not found in other cells, and these glycans play critical roles in high-order brain functions and various neurological disorders. However, little is known about how the expression of these neural glycans is established and maintained. Here, we investigated which glycans are expressed in each primary neural cell and how epigenetics contributes to the expression of neural glycans. We first isolated primary neurons, astrocytes, and fibroblasts from mouse embryos and carried out N-glycomic and glycosyltransferase (GlycoT)-transcriptomic analyses to identify N-glycans specific to a particular neural cell type and to clarify the underlying transcriptional basis. We next treated the cells with epigenetic drugs (5-aza-2'-deoxycytidine (5-aza) and trichostatin A (TSA)) and characterized the changes in GlycoT-transcriptomes and N-glycomes. We found that the N-glycomes in neurons were highly stable and resistant to epigenetic stimulation. In contrast, astrocytes showed dynamic N-glycan changes after treatment, such as a shift in the linkages of sialic acid. These results provide novel insights into how the expression of neural glycans is maintained and epigenetically regulated.

Correction of the Lower Lip With a Cartilage Graft and Lip Resection in Patients With Facioscapulohumeral Muscular Dystrophy.

Facioscapulohumeral muscular dystrophy is an autosomal-dominant, slowly progressive myopathy that involves facial, shoulder, and upper arm muscles. Facial muscle atrophy and weakness leads to drooping of the lower lip, which has unfavorable functional and aesthetic outcomes. While there are several methods to correct drooping of the lower lip, including lip resection, free vascularized muscle transfer, and fascia suspension, there are no reports describing the use of an auricular cartilage graft to elevate the lip. The use of an auricular cartilage graft has several advantages, including a less invasive procedure and a longer-lasting effect. In this study, 3 patients with facioscapulohumeral muscular dystrophy underwent surgery involving an auricular cartilage graft with lip resection to sustain the lower lip, and satisfactory results were obtained. This procedure is simple and minimally invasive; thus, the authors believe that this is an appropriate technique to correct similar patients of lip deformity.

Synaptic plasticity associated with a memory engram in the basolateral amygdala.

Synaptic plasticity is a cellular mechanism putatively underlying learning and memory. However, it is unclear whether learning induces synaptic modification globally or only in a subset of neurons in associated brain regions. In this study, we genetically identified neurons activated during contextual fear learning and separately recorded synaptic efficacy from recruited and nonrecruited neurons in the mouse basolateral amygdala (BLA). We found that the fear learning induces presynaptic potentiation, which was reflected by an increase in the miniature EPSC frequency and by a decrease in the paired-pulse ratio. Changes occurred only in the cortical synapses targeting the BLA neurons that were recruited into the fear memory trace. Furthermore, we found that fear learning reorganizes the neuronal ensemble responsive to the conditioning context in conjunction with the synaptic plasticity. In particular, the neuronal activity during learning was associated with the neuronal recruitment into the context-responsive ensemble. These findings suggest that synaptic plasticity in a subset of BLA neurons contributes to fear memory expression through ensemble reorganization.

Head and neck reconstruction by using extended pectoralis major myocutaneous flap.

BACKGROUND: Pectoralis major flaps have been the workhorse in head and neck region reconstructions till date. However, pectoralis major flaps have disadvantages, including limitations regarding flap range and less stable blood flow than that in free flaps. Here, we report on the safe reconstruction to the oral cavity and neck area by using extended pectoralis major flaps. These flaps include both the normal vessels that feed pectoralis major flaps (the thoracoacromial artery and vein) and the lateral thoracic artery and vein to stabilize blood flow and expand flap survival area caudally. METHODS: Eight patients who had undergone reconstruction with extended pectoralis major flaps after the resection of head and neck cancers from June 2009 to March 2013. In all cases, the pectoralis major flap was elevated with a vascular pedicle comprising the thoracoacromial artery and vein and the lateral thoracic artery and vein. RESULTS: No blood circulation disorders, such as ischemia or congestion, were observed after the flaps were elevated and moved to the resected areas. All flaps were sutured on without difficulty. The area the flaps were harvested from was closed in a single stage. No postoperative complications such as hematoma, abscess, or fistula were observed. CONCLUSION: Extended pectoralis major flaps have a wide range and more stable blood flow, so they are thought to be useful in situations in which free flaps cannot be used for a variety of reasons.

Pilot study of intraperitoneal administration of triamcinolone acetonide for cancerous ascites in patients with end-stage gynecological cancer.

OBJECTIVE: Patients with end-stage cancer have poorly controlled ascites retention resulting due to cancerous peritonitis. We intraperitoneally administered triamcinolone acetonide (TA) to patients with end-stage gynecological cancer as a pilot study, and our treatment results are reported herein. PATIENTS AND METHODS: We enrolled 26 patients with end-stage gynecological cancer requiring frequent abdominal paracentesis for ascites drainage between April 2010 and September 2012. The volume of ascites drainage was 2000 to 3000 mL per drainage session, and TA at 10 mg/kg was intraperitoneally administered after drainage. We compared abdominal paracentesis intervals, performance status (PS), total protein level, albumin level, white blood cell count, changes in C-reactive protein (CRP) level, and adverse events before and after TA use. RESULTS: Triamcinolone acetonide was administered to 26 patients for a total of 59 times. The abdominal paracentesis intervals, PS, and mean (SD) of C-reactive protein before and after TA use were 13.2 (12.6) days and 21.9 (23.6) days (P = 0.0117), 2.4 (0.7) and 1.6 (1.1) (P < 0.0001), and 7.5 (5.2) mg/dL and 5.5 (5.0) mg/dL (P = 0.007), respectively. With regard to adverse events, abdominal pain of grade 2 was observed once (1.7%), but there were no other acute adverse events. Four subjects (15.4%) had intestinal perforation. CONCLUSIONS: Intraperitoneal administration of TA after drainage was considered to be a useful treatment, as it seems to extend paracentesis intervals and improve PS while maintaining quality of life for end-stage gynecological cancer patients with massive ascites.

A pilot study of oxaliplatin with oral S-1 as second-line chemotherapy for patients with recurrent adenocarcimona of the uterine cervix.

BACKGROUND: The efficacy and safety of S-1/oxaliplatin (SOX) therapy in patients with recurrent adenocarcinoma of the uterine cervix were examined in a pilot study. PATIENTS AND METHODS: S-1 was orally administered for 14 days at a dose of 80-120 mg/body/day to 7 patients with recurrent adenocarcinoma of the uterine cervix, with oxaliplatin being administered intravenously at a dose of 100 mg/m(2) on day 1. Each therapy cycle was 21 days, and the patients received 6 cycles at most. The antitumor effect, adverse events, progression-free survival (PFS), and overall survival (OS) were investigated. RESULTS: The median age of the patients was 49 years. The antitumor effect was rated as a complete response in 2 patients, partial response in 2, and stable disease in 3. The overall response rate was 57.1 %, and the disease control rate was 100 %. Regarding hematological toxicities of grade 3 or more, leukopenia, neutropenia and thrombocytopenia occurred in 42.9, 28.6 and 14.3 %, respectively; regarding non-hematological toxicities, grade 3 rectovaginal fistula occurred in 14.3 %, as well as grade 2 fatigue in 14.3 % of the patients. The median PFS and OS were 5 months (range 3-9 months) and 7 months (range 4-43 months), respectively. CONCLUSIONS: These results suggest that SOX therapy is useful for the treatment of recurrent adenocarcinoma of the uterine cervix, having a promising antitumor effect and minimal adverse effects. It was also suggested that SOX therapy may contribute to improving the prognosis for patients with adenocarcinoma of the uterine cervix.

Triple simultaneous primary invasive gynecological malignancies: a case report.

Double gynecologic cancer (primary cancers in two organs) is relatively rare. However, triple gynecologic cancer (primary cancers in three organs) is extremely rare. We experienced a case of triple cancer, with primary cervical, endometrial and ovarian cancers, each showing different histopathological features. A 50-year-old woman with a preoperative diagnosis of cervical cancer stage Ib1 with a pathological diagnosis of mucinous adenocarcinoma underwent radical hysterectomy. The pathological diagnoses of the extracted masses were endometrioid adenocarcinoma in the uterine corpus and serous adenocarcinoma in the left ovary. Consequently, triple cancer was diagnosed. After the operation, six cycles of a paclitaxel/carboplatin regimen were administered, and no relapse of the cancers has been observed to date. To our knowledge, this is only the second case report in the international literature of concurrent gynecologic triple cancers of epithelial origin; that is, invasive cervical, endometrial and ovarian cancers, each with different histopathological features.

Kirigami electronics for long-term electrophysiological recording of human neural organoids and assembloids.

Realizing the full potential of organoids and assembloids to model neural development and disease will require improved methods for long-term, minimally invasive recording of electrical activity. Current technologies, such as patch clamp, penetrating microelectrodes, planar electrode arrays and substrate-attached flexible electrodes, do not allow chronic recording of organoids in suspension, which is necessary to preserve architecture. Inspired by kirigami art, we developed flexible electronics that transition from a two-dimensional to a three-dimensional basket-like configuration with either spiral or honeycomb patterns to accommodate the long-term culture of organoids in suspension. Here we show that this platform, named kirigami electronics (KiriE), integrates with and enables chronic recording of cortical organoids for up to 120 days while preserving their morphology, cytoarchitecture and cell composition. We demonstrate integration of KiriE with optogenetic and pharmacological manipulation and modeling phenotypes related to a genetic disease. Moreover, KiriE can capture corticostriatal connectivity in assembloids following optogenetic stimulation. Thus, KiriE will enable investigation of disease and activity patterns underlying nervous system assembly.