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Polydimethylsiloxane (PDMS) is used as a flexible cell culture substrate in medical and biological research fields. It has been demonstrated that surface modification by oxygen plasma irradiation was performed to improve cell adhesion, because PDMS has poor cell adhesiveness. However, the surface modification effect was not sufficient due to the flexibility of PDMS. In this study, active oxygen and UV lights were exposed to PDMS surface to improve the cell adhesion. The active oxygen was generated by a UV lamp emitting at wavelengths of 185 nm and 254 nm. The surface modification effect of PDMS before and after exposure of active oxygen and UV lights were evaluated. As a result, although the surface roughness did not change before and after exposure of active oxygen and UV lights, the wettability was improved. In addition, temporal change of PDMS surface after exposure of active oxygen and UV lights was smaller than that after plasma irradiation. Because the formation of silicon oxide layer on the surface was confirmed, it was considered that this layer prevented the penetration of polar groups getting into the PDMS substrate. Furthermore, osteoblast-like cells on the PDMS after exposure of active oxygen and UV lights were adhered and extend well. Therefore, it was demonstrated that a stable surface modification of PDMS surface was achieved by exposure of active oxygen and UV lights.

Surface modification of polystyrene (PS) dish used as a cell culture substrate is an indispensable strategy to enhance cell adhesion. In general, plasma treatment is employed to enhance the hydrophilic nature on the PS dish surface, and sterilization treatment of the PS dish is performed after the plasma treatment. We reported on a simultaneous process of surface modification and sterilization on the PS dish in a sterilization bag by using active oxygen species (AOS) generated via ultraviolet (UV) lamps, whose wavelength are 185 and 254 nm respectively. Herein, we attempt to investigate the dependency of the distance between UV lamp and PS dish on the surface modification by using the AOS. After exposure of AOS, the oxygen content of the PS dish was increased, whereas the water contact angle was decreased along with the decrement of the distance between PS dish and UV lamp owing to increase in the AOS concentration. Cell adhesion was also enhanced with decrease of the distance between PS dish and UV lamp compared with untreated PS. Especially, chemical states such as atomic concentration and chemical bonding affect cell adhesion rather than the surface wettability. Illumination of the UV lamps and AOS concentration at the PS dish surface affects the resultant cell adhesion.

Abstract Primates must adapt to changing environments by optimizing their behavior to make beneficial choices. At the core of adaptive behavior is the orbitofrontal cortex (OFC) of the brain, which updates choice value through direct experience or knowledge-based inference. Here, we identify distinct neural circuitry underlying these two separate abilities. We designed two behavioral tasks in which two male macaque monkeys updated the values of certain items, either by directly experiencing changes in stimulus-reward associations, or by inferring the value of unexperienced items based on the task’s rules. Chemogenetic silencing of bilateral OFC combined with mathematical model-fitting analysis revealed that monkey OFC is involved in updating item value based on both experience and inference. In vivo imaging of chemogenetic receptors by positron emission tomography allowed us to map projections from the OFC to the rostromedial caudate nucleus (rmCD) and the medial part of the mediodorsal thalamus (MDm). Chemogenetic silencing of the OFC-rmCD pathway impaired experience-based value updating, while silencing the OFC-MDm pathway impaired inference-based value updating. Our results thus demonstrate dissociable contributions of distinct OFC projections to different behavioral strategies, and provide new insights into the neural basis of value-based adaptive decision-making in primates.

Abstract Visual object memory is a fundamental element of various cognitive abilities, and the underlying neural mechanisms have been extensively examined especially in the anterior temporal cortex of primates. However, both macroscopic large-scale functional network in which this region is embedded and microscopic neuron-level dynamics of top-down regulation it receives for object memory remains elusive. Here, we identified the orbitofrontal node as a critical partner of the anterior temporal node for object memory by combining whole-brain functional imaging during rest and a short-term object memory task in male macaques. Focal chemogenetic silencing of the identified orbitofrontal node downregulated both the local orbitofrontal and remote anterior temporal nodes during the task, in association with deteriorated mnemonic, but not perceptual, performance. Furthermore, imaging-guided neuronal recordings in the same monkeys during the same task causally revealed that orbitofrontal top-down modulation enhanced stimulus-selective mnemonic signal in individual anterior temporal neurons while leaving bottom-up perceptual signal unchanged. Furthermore, similar activity difference was also observed between correct and mnemonic error trials before silencing, suggesting its behavioral relevance. These multifaceted but convergent results provide a multiscale causal understanding of dynamic top-down regulation of the anterior temporal cortex along the ventral fronto-temporal network underpinning short-term object memory in primates.

Recent advancements in chemogenetic tools, such as designer receptors exclusively activated by designer drugs (DREADDs), allow the simultaneous manipulation of activity over a specific, broad brain region in nonhuman primates. However, the introduction of DREADDs into large and complexly shaped cortical sulcus regions of macaque monkeys is technically demanding; previously reported methods are time consuming or do not allow the spatial range of expression to be controlled. In the present report, we describe the procedure for an adeno-associated viral vector (AAV2.1) delivery via handheld injections into the dorsolateral prefrontal cortex (Brodmann’s area 9/46) of macaque monkeys, with reference to pre-scanned anatomical magnetic resonance images. This procedure allows the precise delivery of DREADDs to a specific cortical region.Key features• This article describes the procedures for injecting viral vectors encoding functional proteins for chemogenetic manipulation into targeted cortical sulcus regions.• The protocol requires magnetic resonance imaging for the accurate estimation of the injection sites prior to surgery.• Viral vector solutions are injected using a handheld syringe under microscopic guidance.• This protocol allows for the precise introduction of designer receptors exclusively activated by designer drugs (DREADDs) to large and complex cortical regions.

Pharmacological and surgical treatments of epilepsy can have unsatisfactory outcomes, so a more targeted and on-demand approach is desirable. Here, the authors demonstrate the usage of inhibitory chemogenetics in male nonhuman primates to attenuate the magnitude and spread of cortical seizures and subsequent body convulsions.

ObjectiveTo verify understanding and awareness of fertility preservation (FP) in pediatric patients undergoing FP treatments.MethodsA questionnaire survey was conducted before and after explanation of fertility issues and FP treatments for patients 6–17 years old who visited or were hospitalized for the purpose of ovarian tissue cryopreservation (OTC) or oocyte cryopreservation (OC), or sperm cryopreservation between October 2018 and April 2022. This study was approved by the institutional review board at St. Marianna University School of Medicine (No. 4123, UMIN000046125).ResultParticipants in the study comprised 36 children (34 girls, 2 boys). Overall mean age was 13.3 ± 3.0 years. The underlying diseases were diverse, with leukemia in 14 patients (38.9%), brain tumor in 4 patients (11.1%). The questionnaire survey before the explanation showed that 19 patients (52.8%) wanted to have children in the future, but 15 (41.7%) were unsure of future wishes to raise children. And most children expressed some degree of understanding of the treatment being planned for the underlying disease (34, 94.4%). Similarly, most children understood that the treatment would affect their fertility (33, 91.7%). When asked if they would like to hear a story about how to become a mother or father after FP which including information of FP, half answered “Don’t mind” (18, 50.0%). After being provided with information about FP treatment, all participants answered that they understood the adverse effects on fertility of treatments for the underlying disease. Regarding FP treatment, 32 children (88.9%) expressed understanding for FP and 26 (72.2%) wished to receive FP. “Fear” and “Pain” and “Costs” were frequently cited as concerns about FP. Following explanations, 33 children (91.7%) answered “Happy I heard the story” and no children answered, “Wish I hadn’t heard the story”. Finally, 28 of the 34 girls (82.4%) underwent OTC and one girl underwent OC.DiscussionThe fact that all patients responded positively to the explanations of FP treatment is very informative. This is considered largely attributable to the patients themselves being involved in the decision-making process for FP.ConclusionsExplanations of FP for children appear valid if age-appropriate explanations are provided.

The term ‘temporal discounting’ describes both choice preferences and motivation for delayed rewards. Here we show that neuronal activity in the dorsal part of the primate caudate head (dCDh) signals the temporally discounted value needed to compute the motivation for delayed rewards. Macaque monkeys performed an instrumental task, in which visual cues indicated the forthcoming size and delay duration before reward. Single dCDh neurons represented the temporally discounted value without reflecting changes in the animal’s physiological state. Bilateral pharmacological or chemogenetic inactivation of dCDh markedly distorted the normal task performance based on the integration of reward size and delay, but did not affect the task performance for different reward sizes without delay. These results suggest that dCDh is involved in encoding the integrated multi-dimensional information critical for motivation.

For hereditary spherocytosis complicated by cholelithiasis, cholecystectomy is simultaneously performed with splenectomy. However, jaundice promptly disappears after removing the spleen, and the risk for recurrent cholelithiasis decreases in majority of cases; gallbladder-preserving cholecystolithotomy can be an option for such patients. We report a case of a 6-year-old boy with hereditary spherocytosis who was referred by a previous physician for the chief complaint of anemia (hemoglobin level, 7–8 g/dl). Abdominal ultrasound and CT revealed numerous small calculi in the spleen and gallbladder. The patient developed calculous cholecystitis twice. Hence, laparoscopic splenectomy and gallbladder-preserving cholecystolithotomy were simultaneously performed. The operating time was 2 h and 58 min, and the blood loss was 45 ml. No postoperative complication developed, and the patient was discharged 5 days after the operation. To date, i.e., a year after the operation, no recurrent cholelithiasis has been observed in the patient.

Neural mechanisms of working memory, particularly its visuospatial aspect, have long been studied in non-human primates. On the other hand, rodents are becoming more important in systems neuroscience, as many of the innovative research methods have become available for them. There has been a question on whether primates and rodents have similar neural backgrounds for working memory. In this paper, we carried out a comparative overview of the neural mechanisms of visuospatial working memory in monkeys and rats. In monkeys, a number of lesion studies indicate that the brain region most responsible for visuospatial working memory is the ventral dorsolateral prefrontal cortex (vDLPFC), as the standard tests for visuospatial working memory, such as delayed response and delayed alternation tasks, are impaired by lesions in this region. Single-unit studies revealed a characteristic firing pattern in neurons in this area, a sustained delay activity. Further studies indicated that the information maintained in the working memory, such as cue location and response direction in a delayed response, is coded in the sustained delay activity. In rats, an area comparable to the monkey vDLPFC was found to be the dorsal part of the medial prefrontal cortex (mPFC), as the delayed alternation in a T-maze is impaired by its lesion. Recently, the delay sustained activity similar to that found in monkeys has been found in the dorsal mPFC of rats performing the delayed response task. Furthermore, anatomical studies indicate that the vDLPFC in monkeys and the dorsal mPFC in rats have much in common, such as that they are both the major targets of parieto-frontal projections. Thus lines of evidence indicate that in both monkeys and rodents, the prefrontal cortex plays a critical role in working memory.

The glycoprotein (G) of rabies virus (RV) is required for binding to neuronal receptors and for viral entry. G-deleted RV vector is a powerful tool for investigating the organization and function of the neural circuits. It gives the investigator the ability to genetically target initial infection to particular neurons and to control trans-synaptic propagation. In this study we have quantitatively evaluated the effect of G gene deletion on the cytotoxicity and transgene expression level of the RV vector. We compared the characteristics of the propagation-competent RV vector (rHEP5.0-CVSG-mRFP) and the G-deleted RV vector (rHEP5.0-ΔG-mRFP), both of which are based on the attenuated HEP-Flury strain and express monomeric red fluorescent protein (mRFP) as a transgene. rHEP5.0-ΔG-mRFP showed lower cytotoxicity than rHEP5.0-CVSG-mRFP, and within 16 days of infection we found no change in the basic electrophysiological properties of neurons infected with the rHEP5.0-ΔG-mRFP. The mRFP expression level of rHEP5.0-ΔG-mRFP was much higher than that of rHEP5.0-CVSG-mRFP, and 3 days after infection the retrogradely infected neurons were clearly visualized by the expressed fluorescent protein without any staining. This may be due to the low cytotoxicity and/or the presumed change in the polymerase gene (L) expression level of the G-deleted RV vector. Although the mechanisms remains to be clarified, the results of this study indicate that deletion of the G gene greatly improves the usability of the RV vector for studying the organization and function of the neural circuits by decreasing the cytotoxicity and increasing the transgene expression level.