Prediction Model for Severe Thrombocytopenia Induced by Gemcitabine Plus Cisplatin Combination Therapy in Patients with Urothelial Cancer.

BACKGROUND: Chemotherapy-induced thrombocytopenia is often a use-limiting adverse reaction to gemcitabine and cisplatin (GC) combination chemotherapy, reducing therapeutic intensity, and, in some cases, requiring platelet transfusion. OBJECTIVE: A retrospective cohort study was conducted on patients with urothelial cancer at the initiation of GC combination therapy and the objective was to develop a prediction model for the incidence of severe thrombocytopenia using machine learning. METHODS: We performed receiver operating characteristic analysis to determine the cut-off values of the associated factors. Multivariate analyses were conducted to identify risk factors associated with the occurrence of severe thrombocytopenia. The prediction model was constructed from an ensemble model and gradient-boosted decision trees to estimate the risk of an outcome using the risk factors associated with the occurrence of severe thrombocytopenia. RESULTS: Of 186 patients included in this study, 46 (25%) experienced severe thrombocytopenia induced by GC therapy. Multivariate analyses revealed that platelet count ≤ 21.4 (×104/µL) [odds ratio 7.19, p < 0.01], hemoglobin ≤ 12.1 (g/dL) [odds ratio 2.41, p = 0.03], lymphocyte count ≤ 1.458 (×103/µL) [odds ratio 2.47, p = 0.02], and dose of gemcitabine ≥ 775.245 (mg/m2) [odds ratio 4.00, p < 0.01] were risk factors of severe thrombocytopenia. The performance of the prediction model using these associated factors was high (area under the curve 0.76, accuracy 0.82, precision 0.68, recall 0.50, and F-measure 0.58). CONCLUSIONS: Platelet count, hemoglobin level, lymphocyte count, and gemcitabine dose contributed to the development of a novel prediction model to identify the incidence of GC-induced severe thrombocytopenia.

Impact of an enhanced recovery protocol in frail patients after intracorporeal urinary diversion.

OBJECTIVE: To determine whether an enhanced recovery after surgery (ERAS) protocol enhances bowel recovery and reduces postoperative ileus (POI) in both non-frail and frail patients after robot-assisted radical cystectomy with intracorporeal urinary diversion (iRARC). PATIENTS AND METHODS: This retrospective cohort study included 186 patients (104 with and 82 without ERAS) who underwent iRARC between 2012 and 2023. 'Frail' patients was defined as those with a low Geriatric-8 questionnaire score (≤13). The primary outcomes were postoperative bowel recovery and the incidence of POI. Secondary outcomes included length of stay (LOS), 30- and 90-day complications, 90-day readmission rate, and POI predictors. RESULTS: The ERAS group exhibited a significantly shorter LOS, early bowel recovery, a lower POI rate, fewer 90-day high-grade complications, and fewer 90-day readmissions than the non-ERAS group in the entire cohort. Non-frail patients in the ERAS group had a lower rate of POI (7.1% vs. 22.1%; P = 0.008), whereas ERAS did not reduce POI in frail patients (44.1% vs. 36.6%; P = 0.50). In the multivariate analysis, ERAS was associated with a reduced risk of POI in both the entire cohort (odds ratio [OR] 0.39, P = 0.01) and in non-frail patients (OR 0.24, P = 0.01), whereas ERAS was not likely to reduce POI (OR 1.14, P = 0.70) in frail patients. Prehabilitation was identified as a favourable predictor of POI. CONCLUSIONS: The ERAS protocol did not reduce POI in frail patients after iRARC, although it enhanced bowel recovery and reduced POI in non-frail patients. Prehabilitation for frail patients might reduce POI.

Assessing the efficacy of target adaptive sampling long-read sequencing through hereditary cancer patient genomes.

Innovations in sequencing technology have led to the discovery of novel mutations that cause inherited diseases. However, many patients with suspected genetic diseases remain undiagnosed. Long-read sequencing technologies are expected to significantly improve the diagnostic rate by overcoming the limitations of short-read sequencing. In addition, Oxford Nanopore Technologies (ONT) offers adaptive sampling and computationally driven target enrichment technology. This enables more affordable intensive analysis of target gene regions compared to standard non-selective long-read sequencing. In this study, we developed an efficient computational workflow for target adaptive sampling long-read sequencing (TAS-LRS) and evaluated it through application to 33 genomes collected from suspected hereditary cancer patients. Our workflow can identify single nucleotide variants with nearly the same accuracy as the short-read platform and elucidate complex forms of structural variations. We also newly identified several SINE-R/VNTR/Alu (SVA) elements affecting the APC gene in two patients with familial adenomatous polyposis, as well as their sites of origin. In addition, we demonstrated that off-target reads from adaptive sampling, which is typically discarded, can be effectively used to accurately genotype common single-nucleotide polymorphisms (SNPs) across the entire genome, enabling the calculation of a polygenic risk score. Furthermore, we identified allele-specific MLH1 promoter hypermethylation in a Lynch syndrome patient. In summary, our workflow with TAS-LRS can simultaneously capture monogenic risk variants including complex structural variations, polygenic background as well as epigenetic alterations, and will be an efficient platform for genetic disease research and diagnosis.

Robot-assisted retroperitoneal lymph node dissection: Initial experience in Japan.

For patients with testicular tumors who need the surgical management, open retroperitoneal lymph node dissection (O-RPLND) is considered the gold standard treatment. However, recently, robot-assisted RPLND (R-RPLND) has gained popularity as a minimally invasive therapy alternative to O-RPLND and laparoscopic RPLND. Here, we report the case of a 32-year-old man presenting with a left testicular teratoma with several enlarged left para-aortic lymph nodes. After the orchiectomy, the patient underwent R-RPLND with an operation time of 279 min, console time of 189 min, bleeding volume of 59 mL, and no significant complications, resulting in a successful outcome. To the best of our knowledge, this is the first reported case of R-RPLND in Japan. Based on our experience, R-RPLND may provide safe and effective outcomes; however, further research is required before the widespread implementation of this technique.

pCO2 decrement through alkalinity enhancement and biological production in a shallow-water ecosystem constructed using steelmaking slag.

Ocean-based carbon dioxide removal has gained immense attention as a countermeasure against climate change. The enhancement of ocean alkalinity and the creation of new blue carbon ecosystems are considered effective approaches for this. To evaluate the function of steelmaking slag from the viewpoints of CO2 reduction and creation of new blue carbon ecosystems, we conducted a comparative experiment using two mesocosms that replicated tidal-flats and shallow-water ecosystems. Initially, approximately 20 seagrasses (Zostera marina) were transplanted into the shallow-water area in the mesocosm tanks. The use of steelmaking slag is expected to increase the pH by releasing calcium and mitigate turbidity by solidifying dredged soil. In the experimental tank, where dredged soil and steelmaking slag were utilized as bed materials, the pH remained higher throughout the experimental period compared with the control tank, which utilized only dredged soil. As a result, pCO2 remained consistently lower in the experimental tank due to mainly its alkaline effect (March 2019: -10 ± 6 µatm, September 2019: -130 ± 47 µatm). The light environment in the control tank deteriorated due to high turbidity, whereas the turbidity in the experimental tank remained low throughout the year. The number of seagrass shoots in the experimental tank was consistently approximately 20, which was higher than that in the control tank. Additionally, more seaweed and benthic algae were observed in the experimental tank, indicating that it was more conducive to the growth of primary producers. In conclusion, tidal-flat and shallow-water ecosystems constructed using dredged soil and steelmaking slag are expected to enhance CO2 uptake and provide a habitat for primary producers that is superior to those constructed using dredged soil only.

Comparing pentafecta outcomes between nerve sparing and non nerve sparing robot-assisted radical prostatectomy in a propensity score-matched study.

Pentafecta (continence, potency, cancer control, free surgical margins, and no complications) is an important outcome of prostatectomy. Our objective was to assess the pentafecta achievement between nerve-spring and non-nerve-sparing robot-assisted radical prostatectomy (RARP) in a large single-center cohort. The study included 1674 patients treated with RARP between August 2009 and November 2022 to assess the clinical outcomes. Cox regression analyses were performed to evaluate the prognostic significance of RARP for pentafecta achievement, and 1:1 propensity score matching (PSM) was performed between the nerve-sparing and non-nerve-sparing to test the validity of the results. Pentafecta definition included continence, which was defined as the use of zero pads; potency, which was defined as the ability to achieve and maintain satisfactory erections or ones firm enough for sexual activity and sexual intercourse. The biochemical recurrence rate was defined as two consecutive PSA levels > 0.2 ng/mL after RARP; 90-day Clavien-Dindo complications ≤ 3a; and a negative surgical pathologic margin. The median follow-up period was 61.3 months (IQR 6-159 months). A multivariate Cox regression analysis demonstrated that pentafecta achievement was significantly associated with nerve-sparing (NS) approach (1188 patients) (OR 4.16; 95% CI 2.51-6.9), p < 0.001), unilateral nerve preservation (983 patients) (OR 3.83; 95% CI 2.31-6.37, p < 0.001) and bilateral nerve preservation (205 patients) (OR 7.43; 95% CI 4.14-13.36, p < 0.001). After propensity matching, pentafecta achievement rates in the NS (476 patients) and non-NS (476 patients) groups were 72 (15.1%) and 19 (4%), respectively. (p < 0.001). NS in RARP offers a superior advantage in pentafecta achievement compared with non-NS RARP. This validation study provides the pentafecta outcome after RARP associated with nerve-sparing in clinical practice.

A complex rearrangement between APC and TP63 associated with familial adenomatous polyposis identified by multimodal genomic analysis: a case report.

Genetic testing of the APC gene by sequencing analysis and MLPA is available across commercial laboratories for the definitive genetic diagnosis of familial adenomatous polyposis (FAP). However, some genetic alterations are difficult to detect using conventional analyses. Here, we report a case of a complex genomic APC-TP63 rearrangement, which was identified in a patient with FAP by a series of genomic analyses, including multigene panel testing, chromosomal analyses, and long-read sequencing. A woman in her thirties was diagnosed with FAP due to multiple polyps in her colon and underwent total colectomy. Subsequent examination revealed fundic gland polyposis. No family history suggesting FAP was noted except for a first-degree relative with desmoid fibromatosis. The conventional APC gene testing was performed by her former doctor, but no pathogenic variant was detected, except for 2 variants of unknown significance. The patient was referred to our hospital for further genetic analysis. After obtaining informed consent in genetic counseling, we conducted a multigene panel analysis. As insertion of a part of the TP63 sequence was detected within exon16 of APC, further analyses, including chromosomal analysis and long-read sequencing, were performed and a complex translocation between chromosomes 3 and 5 containing several breakpoints in TP63 and APC was identified. No phenotype associated with TP63 pathogenic variants, such as split-hand/foot malformation (SHFM) or ectrodactyly, ectodermal dysplasia, or cleft lip/palate syndrome (EEC) was identified in the patient or her relatives. Multimodal genomic analyses should be considered in cases where no pathogenic germline variants are detected by conventional genetic testing despite an evident medical or family history of hereditary cancer syndromes.

Long days restore regular estrous cyclicity in mice lacking circadian rhythms.

Many female mammals have recurring cycles of ovulation and sexual behaviors that are regulated by reproductive hormones and confer reproductive success. In addition to sexual behaviors, circadian behavioral rhythms of locomotor activity also fluctuate across the estrous cycle in rodents. Moreover, there is a bidirectional relationship between circadian rhythms and estrous cyclicity since mice with disrupted circadian rhythms also have compromised estrous cycles resulting in fewer pregnancies. In the present study, we assessed whether extending day length, which alters circadian rhythms, normalizes estrous cyclicity in mice. We found that Period (Per) 1/2/3 triple knockout (KO) mice, that have disabled canonical molecular circadian clocks, have markedly disrupted estrous cycles. Surprisingly, extending the day length by only 2 h per day restored regular 4- or 5-day estrous cycles to Per1/2/3 KO mice. Longer days also induced consistent 4-day, rather than 5-day, estrous cycles in wild-type C57BL/6J mice. These data demonstrate that extending daytime light exposure could be used for enhancing reproductive success.

Combination of deep learning and ensemble machine learning using intraoperative video images strongly predicts recovery of urinary continence after robot-assisted radical prostatectomy.

BACKGROUND: We recently reported the importance of deep learning (DL) of pelvic magnetic resonance imaging in predicting the degree of urinary incontinence (UI) following robot-assisted radical prostatectomy (RARP). However, our results were limited because the prediction accuracy was approximately 70%. AIM: To develop a more precise prediction model that can inform patients about UI recovery post-RARP surgery using a DL model based on intraoperative video images. METHODS AND RESULTS: The study cohort comprised of 101 patients with localized prostate cancer undergoing RARP. Three snapshots from intraoperative video recordings showing the pelvic cavity (prior to bladder neck incision, immediately following prostate removal, and after vesicourethral anastomosis) were evaluated, including pre- and intraoperative parameters. We evaluated the DL model plus simple or ensemble machine learning (ML), and the area under the receiver operating characteristic curve (AUC) was analyzed through sensitivity and specificity. Of 101, 64 and 37 patients demonstrated "early continence (using 0 or 1 safety pad at 3 months post-RARP)" and "late continence (others)," respectively, at 3 months postoperatively. The combination of DL and simple ML using intraoperative video snapshots with clinicopathological parameters had a notably high performance (AUC, 0.683-0.749) to predict early recovery from UI after surgery. Furthermore, combining DL with ensemble artificial neural network using intraoperative video snapshots had the highest performance (AUC, 0.882; sensitivity, 92.2%; specificity, 78.4%; overall accuracy, 85.3%) to predict early recovery from post-RARP incontinence, with similar results by internal validation. The addition of clinicopathological parameters showed no additive effects for each analysis using DL, EL and simple ML. CONCLUSION: Our findings suggest that the DL algorithm with intraoperative video imaging is a reliable method for informing patients about the severity of their recovery from UI after RARP, although it is not clear if our methods are reproducible for predicting long-term UI and pad-free continence.

Circadian rhythm of PERIOD2::LUCIFERASE expression in the trigeminal ganglion of mice.

Introduction: The trigeminal nerve conveys delicate sensations such as warmth, pain, and tactile pressure in the oral and facial regions, and most trigeminal afferent cell bodies are located in the trigeminal ganglion. Our previous study has shown that sensations in trigeminal nerve innervated areas, specifically in the maxillofacial region, exhibit diurnal variation and that sensitivity changes time-dependently. In this study, we aimed to clarify the rhythm of expression of clock gene in the trigeminal ganglion of mice to elucidate the mechanism of circadian regulation in the same area. Methods: Immunohistochemistry examined the expression of the PER2 protein in the suprachiasmatic nucleus and trigeminal ganglion of wild-type mice. To measure gene expression as bioluminescence, PERIOD2::LUCIFERASE knock-in (PER2::LUC) mice were used. Unilateral trigeminal ganglion and brain sections including the suprachiasmatic nucleus were incubated ex vivo. Bioluminescence levels were then measured using a highly sensitive photodetector. The same experiments were then conducted with Cry1 gene-deficient (Cry1-/- ) or Cry2 gene-deficient (Cry2-/- ) mice. Results: In the trigeminal ganglion, immunohistochemistry localized PER2 protein expression within the neuronal cell body. Mouse trigeminal ganglion ex vivo tissues showed distinct circadian oscillations in PER2::LUC levels in all genotypes, wild-type, Cry1-/- , and Cry2-/- . The period was shorter in the trigeminal ganglion than in the suprachiasmatic nucleus; it was shorter in Cry1-/- and longer in Cry2-/- mice than in the wild-type mice. Conclusion: The expression of Per2 in neurons of the trigeminal ganglion in ex vivo culture and the oscillation in a distinct circadian rhythm suggests that the trigeminal ganglion is responsible for the relay of sensory inputs and temporal gating through autonomous circadian oscillations.

Diurnal variations of triglyceride accumulation in mouse and bovine adipocyte-derived cell lines.

Several studies have suggested a strong interaction between the circadian clock and lipid metabolism in mammals. The circadian clock is driven by endogenous cyclic gene expression patterns, commonly referred to as clock genes, and transcription-translation negative feedback loops. Clock genes regulate the transcription of some lipid metabolism-related genes; however, the relationship between the circadian clock and triglyceride (TG) accumulation at the cellular level remains unclear. Here, we evaluated rhythms of intracellular TG accumulation levels as well as the expression of clock genes and lipid metabolism-related genes for 54 h in mouse and bovine adipose-derived cell cultures. To the best of our knowledge, this study represents the first report demonstrating that TG accumulation exhibits diurnal variations, with the pattern differing among cell types. Furthermore, we found that expression of clock genes and corresponding lipid metabolism-related genes exhibited circadian rhythms. Our results suggest that the cellular clock regulates lipid metabolism-related genes to relate circadian rhythms of TG accumulation in each cell type. We anticipate that the amount of fat stored depends on the timing of the supply of glucose-the precursor of fat. The findings of this study will contribute to the advancement of chrono-nutrition.

Effect of decreased tongue pressure on dysphagia and survival rate in elderly people requiring long-term care.

Background/purpose: Tongue pressure plays an important role in swallowing function. The purpose of this study is to investigate whether decreased tongue pressure is associated with dysphagia and the development of pneumonia in the elderly requiring long-term care. Materials and methods: Tongue pressure measurement and swallowing videoendoscopic (VE) examination were performed in 60 hospitalized elderly people (33 males and 27 females, with an average age of 84.3 years) to investigate the relationship with the clinical course. Factors related with dysphagia was analyzed by Fisher's exact test and one-way ANOVA, followed by multivariate logistic regression. The relationship between each variable and survival were analyzed by cox regression. Results: Twenty-one patients had dysphagia by VE examination. Multivariate analysis showed that smaller BMI and reduced tongue pressure were significantly correlated with dysphagia. Smaller number of remaining teeth and dysphagia were significantly related to pneumonia-related death. No patients with tongue pressure of larger than 20 kpa died by pneumonia within one year, while in those with tongue pressure of smaller than 20 kpa, one-year cumulative survival rate by pneumonia was 44.3%. Conclusion: Decreased tongue pressure was significantly associated with dysphagia and may increase the risk of pneumonia-related death in the elderly requiring long-term care.

Intermitochondrial signaling regulates the uniform distribution of stationary mitochondria in axons.

In the central nervous system (CNS), many neurons develop axonal arbors that are crucial for information processing. Previous studies have demonstrated that premature axons contain motile and stationary mitochondria, and their balance is important for axonal arborization. However, the mechanisms by which neurons determine the positions of stationary mitochondria as well as their turnover remain to be elucidated. We observed that the distribution of stationary mitochondrial spots along the unmyelinated and nonsynaptic axons is not random but rather relatively uniform both in primary cultured neurons and in tissues. Intriguingly, whereas the positions of each mitochondrial spot changed over time, the overall distribution remained uniform. In addition, local inactivation of mitochondria by KillerRed mediated chromophore-assisted light inactivation (CALI) inhibited the translocation of mitochondrial spots in adjacent axonal regions, suggesting that functional mitochondria enhance the motility of other mitochondria in the vicinity. Signals of ATP:ADP sensor, PercevalHR indicated that the ATP:ADP ratio was relatively high around mitochondria, and treating axons with phosphocreatine (PCr), which supplies ATP, reduced the immobile mitochondria induced by the local mitochondrial inactivation. In a mathematical model, we found that the ATP gradient generated by mitochondria, and ATP dependent regulation of mitochondrial motility could establish uniform mitochondrial distribution. These observations suggest that axons in the CNS possess the system that distributes mitochondria uniformly, and intermitochondrial signaling contribute to the regulation. In addition, our results suggest the possibility that ATP might be one of the molecules mediating the signaling.

Secretin receptor-deficient mice exhibit robust food anticipatory activity.

In mammals, the suprachiasmatic nucleus (SCN) is a principal circadian pacemaker that optimizes the timing of behavioral rhythms and physiological events. Normally, circadian behavioral rhythms are entrained by the environmental light-dark (LD) cycle via the SCN. However, daily rhythms of other synchronizing signals, such as food availability, also emerge. When food availability is restricted to a single recurring daytime meal in nocturnal rodents, they exhibit increased activity during the hours immediately preceding feeding time; this is called food anticipatory activity (FAA). Many reports suggest that FAA is mediated by the food-entrainable oscillator (FEO) with circadian properties, but not the SCN. However, the neural locus and timekeeping mechanisms of the FEO, including its relationship with gastrointestinal hormone signaling, remain unclear. Herein, to examine whether secretin receptor signaling is necessary for the FEO, the effect of daily food restriction was studied in secretin receptor-deficient (Sctr-/-) mice. Adult wild-type (WT) and Sctr-/- mice were housed in separate cages containing a running wheel, with ad libitum food access and in a LD cycle (12 hours:12 hours) for at least 2 weeks. After acclimation to the condition, food access times were gradually restricted and 4-hour restricted feeding lasted over 10 days. Subsequently, mice had ad libitum food access for 2 days and then fasted for 2 days. Thereafter, robust FAAs were observed in both WT and Sctr-/- mice during restricted feeding and subsequent fasting. These results indicate that secretin receptor signaling is not essential for the timekeeping mechanism of FEO.

Effects of sleep position on the treatment response of oral appliance for obstructive sleep apnea.

Objective: This retrospective study aimed to clarify the characteristics of positional obstructive sleep apnea (P-OSA) patients and to examine the relationship between sleep position and the efficacy of oral appliance (OA) therapy.Methods: Seventy-three patients who underwent polysomnography before and after OA therapy were divided into P-OSA or non-positional OSA (NP-OSA) and examined.Results: Forty-seven patients had P-OSA and 26 had NP-OSA. P-OSA was characterized by a relatively high ratio of supine to lateral apnea hypopnea index (AHI) because the lateral AHI of P-OSA was significantly lower than that of NP-OSA. OA therapy was more effective for P-OSA than NP-OSA. Younger age and the presence of P-OSA are useful as predictors of OA therapy efficacy.Discussion: Even for relatively severe OSA, in the case of younger age and/or P-OSA, the application of simple, cost-effective OA therapy might be recommended over other treatment modalities.

Using the in vitro drug sensitivity test to identify candidate treatments for transient abnormal myelopoiesis.

Approximately 20% of patients with transient abnormal myelopoiesis (TAM) die due to hepatic or multiorgan failure. To identify potential new treatments for TAM, we performed in vitro drug sensitivity testing (DST) using the peripheral blood samples of eight patients with TAM. DST screened 41 agents for cytotoxic properties against TAM blasts. Compared with the reference samples of healthy subjects, TAM blasts were more sensitive to glucocorticoids, the mitogen-activated protein kinase kinase (MAP2K) inhibitor trametinib, and cytarabine. Our present results support the therapeutic potential of glucocorticoids and the role of the RAS/MAP2K signalling pathway in TAM pathogenesis.

Role of heterozygous and homozygous alleles in cryptochrome-deficient mice.

The circadian rhythms of physiology and behavior are based on molecular systems at the cellular level, which are regulated by clock genes, including cryptochrome genes, Cry1 and Cry2. In mammals, the circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus maintains the circadian rhythms throughout the body. Cry1 and Cry2 play distinct roles in regulating the circadian rhythm. However, the different effects of manipulating clock genes in heterozygous and homozygous alleles, Cry1 and Cry2, remain unclear. Therefore, this study aimed to understand the haplosufficiency of cryptochrome genes in regulating the circadian system. We examined wheel-running activity rhythms and PER2::LUC expression rhythms in SCN slices and pituitary explants in mice. Compared with wild-type mice, Cry1-/- or Cry2-/- mice had shortened or lengthened periods in free-running behavioral rhythms and PER2::LUC expression in the SCN and pituitary gland. Cry1+/- mice had similar circadian rhythms as wild-type mice, although Cry2+/- mice had lengthened periods. The amplitude of PER2::LUC expression exhibited faster damping in Cry1-/- mice. Therefore, Cry1 deficiency affects the circadian period length and stability of the circadian system. A single allele of Cry2 deficiency affects the circadian rhythm, whereas that of Cry1 deficit is compensated.

Diurnal Variation in Trigeminal Pain Sensitivity in Mice.

Management of time and circadian disruption is an extremely important factor in basic research on pain and analgesia. Although pain is known to vary throughout the day, the mechanism underlying this circadian variation remains largely unknown. In this study, we hypothesized that the process of pain transmission to the central nervous system (after receiving nociceptive stimuli from outside the body) would show day-night differences. Ten-week-old male mice were kept under a strict 12/12-h light/dark cycle for at least 10 days. Formalin was then injected into the second branch region of the trigeminal nerve and the duration of pain-related behaviors (PRBs) was assessed. Immunohistochemical staining was then performed, and the c-Fos-immunopositive cells in the trigeminal spinal tract subnucleus caudalis (Sp5C) were counted. The results showed that the duration of PRBs was longer and the number of c-Fos immunopositive cells in the Sp5C was higher at nighttime than during the day. In addition, the trigeminal ganglia (TG) were extracted from the mice and examined by quantitative real-time PCR to evaluate the daytime and nighttime expression of nociceptive receptors. The results showed that the mRNA expression of transient receptor potential ankyrin 1 in the TG was significantly higher at night than during the day. These results suggest that pain in the trigeminal nerve region is more intense at nighttime, when rodents are active, than during the daytime, partly due to differences in nociceptor expression.

Chronic methamphetamine uncovers a circadian rhythm in multiple-unit neural activity in the dorsal striatum which is independent of the suprachiasmatic nucleus.

The dorsal striatum forms part of the basal ganglia circuit that is a major regulator of voluntary motor behavior. Dysfunction in this circuit is a critical factor in the pathology of neurological (Parkinson's and Huntington's disease) as well as psychiatric disorders. In this study, we employed in vivo real-time monitoring of multiple unit neural activity (MUA) in the dorsal striatum of freely moving mice. We demonstrate that the striatum exhibits robust diurnal and circadian rhythms in MUA that peak in the night. These rhythms are dependent upon the central circadian clock located in the suprachiasmatic nucleus (SCN) as lesions of this structure caused the loss of rhythmicity measured in the striatum. Nonetheless, chronic treatment of methamphetamine (METH) makes circadian rhythms appear in MUA recorded from the striatum of SCN-lesioned mice. These data demonstrate that the physiological properties of neurons in the dorsal striatum are regulated by the circadian system and that METH drives circadian rhythms in striatal physiology in the absence of the SCN. The finding of SCN-driven circadian rhythms in striatal physiology has important implications for an understanding of the temporal regulation of motor control as well as revealing how disease processes may disrupt this regulation.