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Fear memory is defined as the associative (fear-conditioned) memory between the context of a fear experience (conditioned stimulus) and fear itself (unconditioned stimulus). Re-exposure to the conditioned context retrieves the fear memory and triggers a fear response. Fear memories have been observed in both nematodes and humans, suggesting common neural mechanisms. Studies using rodents and other animal models have identified the mechanisms of fear memory processes, such as consolidation, retrieval, reconsolidation, destabilization, and extinction, at the molecular, cellular, circuit, and behavioral levels. This review introduces fear memory processes and their mechanisms.

(Objectives) This study aimed to evaluate the surgical outcomes and functional parameters of lower urinary tract and bowel symptoms in patients who have undergone robot-assisted sacrocolpopexy (RASC) due to pelvic organ prolapse. (Patients and methods) This retrospective study included 110 consecutive RASC cases in the urology department of Ageo Central General Hospital, Japan, from November 2020 to October 2021. The medical records of these patients were retrieved. Data on uroflowmetry, post-void residual urine test, and self-administered questionnaires on urination and defecation were assessed. (Results) The mean operating time was 146 min, and the estimated blood loss was 14.8 ml. The intraoperative, postoperative, and severe complication rates of cases classified as Clavien-Dindo grade IIIa or higher were 0%, 9.1%, and 0%, respectively. The maximum flow rate and post-void residual volume of urine significantly improved after the operation. Similarly, the quality of life (QOL) scores and overactive bladder symptom score (OABSS), as well as the responses for the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) and Urinary Distress Inventory-6 (UDI-6), significantly improved one month after the operation and were sustained for six months. On the other hand, the total scores from the Constipation Scoring System (CSS) and the subscales of the Patient Assessment of Constipation (PAC) -QOL worsened. These scores, except for those of the PAC-QOL satisfaction subscale recovered to the preoperative levels; the PAC-QOL satisfaction subscale scores significantly improved six months postoperatively. The rates of de novo overactive bladder (OAB), stress urinary incontinence (SUI), and constipation one month postoperatively were 8%, 33%, and 10%, respectively. (Conclusions) RASC was performed safely in our institution with acceptable postoperative lower urinary tract and bowel outcomes.

Purpose: Volumetric modulated arc therapy (VMAT) can acquire projection images during rotational irradiation, and cone-beam computed tomography (CBCT) images during VMAT delivery can be reconstructed. The poor quality of CBCT images prevents accurate recognition of organ position during the treatment. The purpose of this study was to improve the image quality of CBCT during the treatment by cycle generative adversarial network (CycleGAN)., Method: Twenty patients with clinically localized prostate cancer were treated with VMAT, and projection images for intra-treatment CBCT (iCBCT) were acquired. Synthesis of PCT (SynPCT) with improved image quality by CycleGAN requires only unpaired and unaligned iCBCT and planning CT (PCT) images for training. We performed visual and quantitative evaluation to compare iCBCT, SynPCT and PCT deformable image registration (DIR) to confirm the clinical usefulness., Result: We demonstrated suitable CycleGAN networks and hyperparameters for SynPCT. The image quality of SynPCT improved visually and quantitatively while preserving anatomical structures of the original iCBCT. The undesirable deformation of PCT was reduced when SynPCT was used as its reference instead of iCBCT., Conclusion: We have performed image synthesis with preservation of organ position by CycleGAN for iCBCT and confirmed the clinical usefulness.

Purpose: Volumetric modulated arc therapy (VMAT) is a rotational intensity-modulated radiotherapy (IMRT) technique capable of acquiring projection images during treatment. The purpose of this study was to reconstruct the dose distribution from respiratory signals and machine parameters acquired during stereotactic body radiotherapy (SBRT)., Methods: The treatment plans created for VMAT-SBRT included the constraint of 1 mm/degree in multileaf collimator (MLC) for a moving phantom and three patients with lung tumors. The respiratory signals were derived from projection images acquired during VMAT delivery, while the machine parameters were derived from machine logs. The respiratory signals and machine parameters were then linked along with the gantry angle. With this data, the dose distribution of each respiratory phase was calculated on the planned four-dimensional CT (4D CT). The doses at the isocenter, the point of max dose and the centroid of the target were compared with those of the corresponding plans., Results and Discussion: In the phantom study, the maximum dose difference between the plan and "in-treatment" results was -0.4% at the centroid of the target. In the patient study, the difference was -1.8 ± 0.4% at the centroid of the target. Dose differences of the evaluated points between 4 and 10 phases were not significant., Conclusion: The present method successfully reconstructed the dose distribution using the respiratory signals and machine parameters acquired during treatment. This is a feasible method for verifying the actual dose for a moving target.

Pavlovian fear conditioning is a model of fear learning and memory. The mechanisms regulating fear conditioning and memory have been investigated in humans and rodents. In this paradigm, animals learn and memorize an association between a conditioned stimulus (CS), such as context, and an unconditioned stimulus (US), such as an electrical footshock that induces fear. Fear memory generated though fear conditioning is stabilized via a memory consolidation process. Moreover, recent studies have shown the existence of memory processes that control fear memory following the retrieval of consolidated memory. Indeed, when fear memory is retrieved by re-exposure to the CS, the retrieved memory is re-stabilized via the reconsolidation process. On the other hand, the retrieval of fear memory by prolonged re-exposure to the CS also leads to fear memory extinction, new inhibitory learning against the fear memory, in which animals learn that they do not need to respond to the CS. Importantly, the reinforcement of fear memory after retrieval (i.e., re-experience such as flashbacks or nightmares) has been thought to be associated with the development of emotional disorders such as post-traumatic stress disorder (PTSD). In this review, I summarize recent progress in studies on the mechanism of fear conditioning and memory consolidation, reconsolidation and extinction, and furthermore, introduce our recent establishment of a mouse PTSD model that shows enhancement of fear memory after retrieval.

Volumetric modulated arc therapy (VMAT) is a rotational intensity-modulated radiotherapy (IMRT) technique capable of acquiring projection images for cone-beam computed tomography (CBCT). Respiratory-correlated cone-beam computed tomography, namely 4D-CBCT, serves to assess the displacement of a tumor position between planning and treatment due to organ motion and respiration, and is important for more accurate radiation therapy. On the other hand, recently, a 320-detector row CT scanner, namely 4D-CT, has become available that allows axial volumetric scanning of a 16-cm-long range in a patient without table movement. The goal of our research is to establish a new method of verification during treatment in stereotactic body radiotherapy. In this study, we compare the movement of the tumor between "before treatment" using 4D-CT and "in treatment" using 4D-CBCT. Three patients (55-68 years of age) with lung tumors underwent CT scans for radiotherapy planning using 4D-CT scans to analyze the movement of the tumor before treatment. The patients were treated by VMAT while acquiring projection images. 4D-CBCT datasets were reconstructed from the projection images using in-house programs. The tumor positions in 4D-CT and 4D-CBCT were detected and the movement of the tumor between "before treatment" and "in treatment" was similar. The movement of the tumors during treatment was predictable from 4D-CT before treatment. Furthermore, 4D-CBCT clarified the tumor position during treatment and could reevaluate the actual tumor position and dose distribution. We have successfully shown the movement of the tumor between "before treatment" using 4D-CT and "in treatment" using 4D-CBCT.

Reconsolidation and extinction of fear memories are induced by re-exposure to the conditioned stimulus (CS) but they appear to be opposite processes; as the fear memory is maintained or inhibited through reconsolidation and extinction, respectively. More importantly, reconsolidation and extinction are thought to be potential targets for the treatment of Post Traumatic Stress Disorder (PTSD). From this view, it is important to understand mechanisms by which reactivated fear memories are reconsolidated or extinguished. Here, we review processes for fear memory regulation including consolidation, reconsolidation and extinction, and discuss implications of fear memory regulation with PTSD.