Effectiveness of vortioxetine for winter depression in bipolar disorder: A case report.

Background: We present a case report on the efficacy of the short-term application of vortioxetine in managing winter depression in patients with seasonal bipolar disorder (BP). Standard treatment strategies for BP may not adequately address seasonal depressive symptoms during winter in patients with seasonal BP patterns. Depressive symptoms during winter may be linked to seasonal changes in serotonin transporter binding, such as a decrease in synaptic serotonin levels, necessitating alternative approaches. Although antidepressants, including vortioxetine, are effective in treating seasonal monopolar depression, their efficacy and safety in treating depression in patients with seasonal BP patterns remain unclear. Case Presentation: This case report focuses on a 44-year-old male patient diagnosed with seasonal BP who had recurrent depressive episodes, specifically during winter. Notably, the patient had a significant decrease in recurrent episodes after short-term seasonal vortioxetine use without inducing mania or rapid cycling. Conclusion: Our study highlights the potential effectiveness of a seasonal, short-term treatment strategy with antidepressants, including vortioxetine, for winter depression in individuals with BP.

Treatment readiness and prognosis for problematic smartphone use: Evaluation of the Stages of Change, Readiness, and Treatment Eagerness Scale (SOCRATES) and log data.

Aim: While moderate smartphone use contributes to information gathering and relationship building, excessive smartphone use, also referred to as problematic smartphone use (PSU), has raised concerns because of its addictive nature and associated health consequences. This study aimed to investigate the relationship between treatment readiness and prognosis in individuals with PSU and to assess the predictive ability of smartphone log data in evaluating treatment readiness. Methods: A sample of 47 patients with PSU participated in this study. Treatment readiness was assessed using the Stages of Change, Readiness, and Treatment Eagerness Scale (SOCRATES), and log data were collected using a smartphone log application. Results: The results showed a significant correlation between baseline SOCRATES scores and the difference in Global Assessment of Functioning scores between baseline and 6 months (Spearman's ρ = 0.640, P-value = .001), suggesting that treatment readiness may explain part of the treatment outcomes (Pearson's r 2 = 0.379, P-value = 0.032). In addition, baseline log data, including the log acquisition rate, showed a positive correlation with treatment readiness (Spearman's ρ = 0.328, P-value = 0.045). Conclusion: These findings provide valuable insights into the relationship between treatment readiness and clinical outcomes in patients with PSU, and suggest the potential of log data as objective indicators of treatment motivation.

Case report: Recurring and treatment-resistant depression in acquired hepatocerebral degeneration due to a congenital portosystemic shunt.

Introduction: Acquired hepatocerebral degeneration (AHD) is a neurological condition associated with cerebral manganese (Mn) accumulation caused by portosystemic shunts (PSS), usually because of advanced liver disease. AHD is diagnosed by the identification of T1-weighted brain magnetic resonance imaging (MRI) hyperintensities coupled with the presence of PSS and neurological symptoms. Clinical presentations primarily involve motor dysfunction and cognitive impairment. As a result of the frequently concurrent hepatic encephalopathy, the psychiatric symptoms of AHD alone remain unclear. This report is the first documentation of unique psychiatric symptoms of AHD due to a congenital PSS (CPSS) and suggests the efficacy of shunt embolization in achieving sustained remission of psychiatric symptoms in such cases. Methods: A 57-year-old Japanese woman presented with recurrent severe depression, pain, and somatosensory hallucinations, along with fluctuating motor dysfunction, including parkinsonism, and cognitive impairments. Psychiatric interventions, including antidepressants, antipsychotics or electroconvulsive therapy, had limited efficacy or did not prevent relapse. Results: T1-weighted MRI showed bilateral hyperintensity in the globus pallidus. No history of Mn exposure or metabolic abnormalities, including copper, was identified. Furthermore, no evidence of liver dysfunction or hyperammonemia was found. Eventually, a gastrorenal shunt was observed on contrast-enhanced abdominal computed tomography. The diagnosis of AHD due to CPSS was made based on the clinical manifestations and abnormal imaging findings. Shunt embolization was performed, which prevented the relapse of psychiatric symptoms and substantially reduced the T1-weighted MRI hyperintensities. Conclusions: This case highlights the potential involvement of AHD in adult-onset psychiatric symptoms, even in the absence of liver disease. Furthermore, this case underscores the efficacy of shunt embolization in treating the psychiatric symptoms of AHD due to CPSS.

Temporal patterns of sleep latency in central hypersomnia and attention deficit hyperactivity disorder: a cluster analysis exploration using Multiple Sleep Latency Test.

Introduction: Excessive daytime sleepiness (EDS) is a crucial symptom that diminishes the quality of life. The primary causes of EDS are central hypersomnia, including narcolepsy type 1 (NT1), type 2 (NT2), and idiopathic hypersomnia (IH). EDS is often associated with other psychiatric disorders, particularly attention deficit hyperactivity disorder (ADHD). The Multiple Sleep Latency Test (MSLT) is the standard assessment tool for EDS. Although the MSLT yields numerous parameters, most are not employed in clinical practice. In this study, we leveraged novel MSLT parameters to discern central hypersomnia and ADHD presence. Our analysis focused on sleep latency variability and employed cluster analysis to identify unique temporal patterns. Methods: We examined the MSLT data from 333 patients; of these, 200 (aged 14-54, mean: 24.9 ± 8.1, years; 114 females) met the inclusion criteria comprising comprehensive data an Apnea-Hypopnea Index (AHI) below 5, and no prior diagnosis of sleep apnea syndrome. We employed a time-course cluster approach that specifically targeted sleep latency variability during the MSLT. Results: Considering both multiple clustering quality evaluations and the study's objectives, we identified 9 distinct clusters. Clusters 1 and 3 predominantly had MSLT-positive results; Cluster 2 was entirely MSLT-positive; Clusters 4, 5, 6, 8, and 9 were mainly MSLT-negative; and Cluster 7 had mixed results. The diagnosis of hypersomnia varied notably among Clusters 1, 2, 3, and 7, with Cluster 2 demonstrating a pronounced tendency towards NT1 and NT2 diagnoses (p < 0.005). However, no significant correlation was observed between ADHD diagnoses and specific sleep latency patterns in any cluster. Conclusions: Our study highlights the value of time-course clustering in understanding sleep latency patterns of patients with central hypersomnia.

Hippocampal volume mediates the relationship of parental rejection in childhood with social cognition in healthy adults.

Childhood abuse reduces hippocampal and amygdala volumes and impairs social cognition, including the ability to recognize facial expressions. However, these associations have been studied primarily in individuals with a history of severe abuse and psychiatric symptoms; researchers have not determined whether these associations can also be observed in healthy adults. In the present study, we analyzed data from 400 healthy adults (208 men and 192 women) at Tamagawa University. Parental rejection reflecting childhood abuse was assessed using the short form of Egna Minnen Beträffande Uppfostran, while social cognition was assessed using the "Fake Smile Detection Task." Hippocampal and amygdala volumes were extracted from T1-weighted magnetic resonance imaging data using FreeSurfer. We found that greater parental rejection resulted in smaller hippocampal and amygdala volumes and poorer performance in the Fake Smile Detection Task. Structural equation modeling analysis supported the model that hippocampal volume mediates maternal rejection effect on performance on the Fake Smile Detection Task, with involvement of the amygdala. These findings are in line with the structural and functional connectivity found between the hippocampus and amygdala and their joint involvement in social cognition. Therefore, parental rejection may affect hippocampal and amygdala volumes and social cognitive function even in symptom-free adults.

The optimal dose of Ramelteon for the better treatment adherence of delayed sleep-wake phase disorder: a dropout rate study.

Background: Evidence regarding the effectiveness of melatonin receptor agonists in treating delayed sleep-wake phase disorder (DSWPD) remains limited. This study aimed to determine the optimal dose of ramelteon, a melatonin receptor agonist, for the better treatment adherence of DSWPD. Methods: The patients who were diagnosed definitely as having DSWPD by board-certified physicians specialized in sleep medicine and started to receive strategically timed ramelteon medications after the diagnosis were included. Data on the initial ramelteon dose and follow-up duration (up to 24 months) were collected retrospectively. Patients with treatment discontinuation, changes in ramelteon dose, or the addition of other sleep-related medications were considered dropouts. Kaplan-Meier estimates, log-rank tests, and Cox regression analyses were performed. Results: Overall, 373 patients were analyzed. The findings revealed that the 2 mg dose of ramelteon was associated with a lower dropout rate compared to the other doses (8 mg, 4 mg, and 1 mg). The dropout rate for the 2 mg group was estimated to have a hazard ratio (HR) of 0.5762 when compared with the 8 mg dose group. Sex did not reveal a significant HR, whereas older age exhibited a small but significant HR (0.9858). Conclusion: For achieving better adherence, a dosing regimen of strategically timed 2 mg ramelteon may be the best for the treatment of DSWPD. The therapeutic dose window for better adherence seems to center approximately 2 mg of ramelteon. Furthermore, caution should be exercised when treating younger patients to prevent dropouts.

Seizure-related stress and arousal responses mediate a relationship between anxiety trait and state in epilepsy.

BACKGROUND: Epilepsy causes substantial psychological distress and anxiety, primarily due to seizures. However, the impact of stress responses and changes in arousal and their association with anxiety patterns in patients with epilepsy (PWE) remains unclear. This study aimed to investigate the relationships among seizures, stress and arousal characteristics, and trait and state anxiety characteristics in PWE. METHODS: Our sample consisted of 159 outpatients with epilepsy recruited from five institutions in Japan in 2020. Participants completed the State-Trait Anxiety Inventory-Form JYZ (STAI) and the Japanese-Stress Arousal Check List (J-SACL). We analyzed the correlations between inventory scores and clinical information. Using principal component analysis (PCA), we derived epilepsy-specific stress/arousal characteristics, which accounted for high arousal and low-stress levels, termed epilepsy-specific stress or arousal response (ESAR), from the J-SACL scores. We conducted a mediation analysis to assess the mediating role of ESAR in the relationship between traits and state anxiety. RESULTS: We found significant correlations between J-SACL stress and arousal factors (r = -0.845, p < 0.001), ESAR and seizure frequency (r = -0.29, p < 0.001), ESAR and trait anxiety scores on the STAI (r = -0.77, p < 0.0001), and ESAR and state anxiety scores on the STAI (r = -0.60, p < 0.0001). Mediation analysis supported by the Monte Carlo method revealed that ESAR significantly mediated the association between trait and state anxiety. CONCLUSIONS: These findings elucidate the epilepsy-specific stress and arousal characteristics and their roles in mediating traits and state anxiety. These results may reflect the long-term clinical course and unique emotion recognition tendencies in epilepsy.

Short-term recurrence of takotsubo syndrome with phenotypic variation: a case report.

Background: Takotsubo syndrome (TTS) is an acute and usually reversible heart failure syndrome characterized as an uncommon left ventricular (LV) cardiomyopathy. Recurrence of TTS is rare, estimated to be 1-6%. We report a rare case of TTS that occurred three times in 2 months but manifested various phenotypes. Case summary: A 68-year-old woman was admitted to our hospital with acute-onset chest pain and hypertension. The coronary angiography findings were normal, although left ventriculography revealed inferior wall hypokinesis, leading to a mid-ventricular TTS diagnosis. She was discharged on Day 3 after her symptoms improved and vitals stabilized. The patient's condition remained uneventful until 2-week post-discharge, when acute chest pain and hypertension recurred. She was admitted again with the same diagnosis. However, LV morphology revealed an apical ballooning pattern, with inferior LV wall hypokinesis. She was discharged on Day 7 after her symptoms and electrocardiography findings improved but was readmitted again 2 weeks later after acute chest pain and hypertension recurred. Left ventriculography performed a third time demonstrated mid-ventricular TTS. The patient was prescribed additional medications and discharged on Day 12. Her electrocardiography findings normalized, and the patient remained asymptomatic without recurrence 4 months after the initial presentation. Discussion: Recurrence and phenotypic change of TTS are rare. Some cases have been reported but occurring months to years after initial diagnosis. Combined treatment with ß-blockers and angiotensin-converting enzyme inhibitors or angiotensin receptor antagonists may be more effective to prevent the recurrence than monotherapies.

Synthesis and Characterization of Octacyano-Fe-Phthalocyanine.

Octacyano-metal-phthalocyanine MPc(CN)8 is a promising n-type stable organic semiconductor material with eight cyano groups, including a strong electron-withdrawing group at its molecular terminals. However, a thorough investigation of MPc(CN)8 has not yet been conducted. Therefore, we synthesized FePc(CN)8 and investigated its crystal structure, chemical and electronic states, electrical properties, photocatalytic activity, and magnetic properties. In this paper, we discuss the various properties of MPc(CN)8 in comparison with those of FePc. X-ray diffraction measurements indicated that the crystal structure of FePc(CN)8 was strongly influenced by the cyano groups and differed from the α- and ß-forms of FePc. The space group P4/mcc structure of FePc(CN)8 was similar to that of the x-form of LiPc. The ultraviolet-visible (UV-vis) absorption spectrum of FePc(CN)8 was observed at wavelengths longer than that of FePc. Density functional theory-based molecular orbital calculations indicated that the energy gap of FePc(CN)8 is smaller than that of FePc, which can lead to the observation of the Q-band in the UV-vis absorption spectrum of FePc(CN)8 at longer wavelengths than that of FePc. Because FePc(CN)8 has a wider optical absorption band in the visible region than FePc, its photocatalytic activity is approximately four times higher than that of FePc. The conductivity of FePc(CN)8 was also higher than that of FePc, which is due to the larger overlap of π-electron clouds of the molecules in the crystal structure of FePc(CN)8. Magnetic measurements revealed that FePc(CN)8 exists in an antiferromagnetic ground state. The magnetic properties of FePc(CN)8 are specific to its crystal structure, with direct exchange interactions between Fe2+ ions and π-electron-mediated interactions. In particular, the Pauli paramagnetic behavior at high temperatures and the antiferromagnetic behavior at low temperatures (Weiss temperature θ = -4.3 ± 0.1 K) are characteristic of the π-d system.

Hyperfocus symptom and internet addiction in individuals with attention-deficit/hyperactivity disorder trait.

Background: Hyperfocus symptom is the intense concentration on a certain object. It is a common but often overlooked symptom in those with attention-deficit/hyperactivity disorder (ADHD). Hyperfocus disrupts attention control and results in a focus on inappropriate behaviors. It allows individuals to focus on internet use and make them use internet excessively. This excessive internet use can lead to an addiction. This study investigated the status of IA and hyperfocus, the mediation effect of hyperfocus in relation to IA, and the relationship between ADHD subtypes and hyperfocus in those with ADHD symptoms. Methods: This web-based cross-sectional study included 3,500 Japanese adults who completed internet-based questionnaires, which included the Adult ADHD Self-Report Scale (ASRS), Internet Addiction Test (IAT), and Hyperfocus Scale (HFS) to assess ADHD symptoms, internet dependence, and hyperfocus symptoms, respectively. The mediating role of HFS in the relationship between ASRS and IAT was assessed by mediation analysis. To analyze the relationship between hyperfocus symptoms and ADHD subtypes, we compared the correlation of HFS with the Inattention and Hyperactive Scores of ASRS. Results: ADHD traits were associated with higher IAT scores (p < 0.001) and higher HFS scores (p < 0.001). Mediation analysis and bootstrap testing showed that HFS significantly mediated the association between ASRS and IAT. Analyses of ADHD subtypes demonstrated that HFS was significantly correlated with the Inattention (R = 0.597, p < 0.001) and Hyperactive (R = 0.523, p < 0.001) Scores. The correlation between HFS and the Inattention Score was significantly higher than that between HFS and the Hyperactive Score (p < 0.001). Conclusion: Our findings suggest that hyperfocus may play an important role in addictive behavior in ADHD as a manifestation of attentional control malfunction.

A case of eosinophilic polyangiitis with granulomatosis that evolved to cardiac arrest due to advanced atrioventricular block.

Cardiac manifestations are the major cause of mortality in patients with eosinophilic granulomatosis with polyangiitis (EGPA). Among these manifestations in EGPA patients, in the literature, there are fewer reports describing bradycardia in EGPA patients than those describing tachycardia. A 50-year-old woman with a history of childhood-onset asthma. At age 28, she was diagnosed with eosinophilic gastroenteritis without the diagnosis of EGPA and was started on a systemic steroid and had maintenance daily dose of 2.5 mg after gradually tapered. She had experiencing dizziness and palpitations 2 weeks after discontinuation of the steroid treatment. At emergency visit, electrocardiography revealed an advanced atrioventricular block of 3:1 or less. Forty-eight minutes after the start of electrocardiography, only a P wave was observed and cardiac arrest occurred for 9 s and temporary emergency pacing was performed immediately. She was diagnosed as EGPA presenting leukocyte count, 16,500/µL, 42.8% of which were eosinophils and sinusitis in computed-tomography. She could be survival by treatment of steroid, following the patient to withdraw from an external pacemaker. She received prednisolone of 60 mg, intravenous cyclophosphamide and intravenous immunoglobulin. She had relapsed presenting peripheral eosinophilia, abdominal and numbness in the toes of the left leg pain, but not arrythmia after tapered of prednisolone. Following additional steroid pulse, she had an increase of prednisolone and continued by intravenous cyclophosphamide, intravenous immunoglobulin and started mepolizumab. We presented a severe case of EGPA presenting an advanced atrioventricular block into cardiac arrest.

Epilepsy surgery for dominant-side mesial temporal lobe epilepsy without hippocampal sclerosis.

Although anterior temporal lobectomy (ATL) is an established surgery for medically intractable mesial temporal lobe epilepsy (MTLE), it can harm memory function, especially in dominant-side MTLE patients without hippocampal sclerosis (HS). To avoid this complication, multiple hippocampal transection (MHT) was developed, but its efficacy has not been fully elucidated. We report the detailed treatment results of MHT compared with that of ATL. We retrospectively analysed the records of 30 patients who underwent surgery for dominant-side MTLE. ATL was completed for 23 patients with HS, and MHT was completed for 7 patients without HS. The seizure control status, number of anti-seizure medicines, neurocognitive function, and psychiatric disorders of each patient were reviewed. The mean follow-up period was 70 months. Seizure control of Engel class I was achieved in 16 patients (70%) in the ALT group versus 5 patients (71%) in the MHT group. The mean number of anti-seizure medicines administered in the ATL group changed significantly from 2.4 to 1.9 (p = 0.01), while that in the MHT group was unchanged (from 2.1 to 2.0, p = 0.77). Eleven patients (48%) in the ATL group developed psychiatric disorders during the postoperative follow-up period, whereas no psychological complications were observed in the MHT group. Neither group showed neurocognitive decline after the surgery in any of the WAIS-III or WMS-R subtests. In conclusion, MHT may achieve reasonable postoperative seizure reduction, preserve neurocognitive function, and reduce postoperative psychiatric complications. Therefore, it can be considered as a therapeutic option for dominant-side MTLE without HS.

Exploring Ripple Waves in the Human Brain.

Ripples are brief (<150 ms) high-frequency oscillatory neural activities in the brain with a range of 140 to 200 Hz in rodents and 80 to 140 Hz in humans. Ripples are regarded as playing an essential role in several aspects of memory function, mainly in the hippocampus. This type of ripple generally occurs with sharp waves and is called a sharp-wave ripple (SPW-R). Extensive research of SPW-Rs in the rodent brain while actively awake has also linked the function of these SPW-Rs to navigation and decision making. Although many studies with rodents unveiled SPW-R function, research in humans on this subject is still sparse. Therefore, unveiling SPW-R function in the human hippocampus is warranted. A certain type of ripples may also be a biomarker of epilepsy. This type of ripple is called a pathological ripple (p-ripple). p-ripples have a wider range of frequency (80-500 Hz) than SPW-Rs, and the range of frequency is especially higher in brain regions that are intrinsically linked to epilepsy onset. Brain regions producing ripples are too small for scalp electrode recording, and intracranial recording is typically needed to detect ripples. In addition, SPW-Rs in the human hippocampus have been recorded from patients with epilepsy who may have p-ripples. Differentiating SPW-Rs and p-ripples is often not easy. We need to develop more sophisticated methods to record SPW-Rs to differentiate them from p-ripples. This paper reviews the general features and roles of ripple waves.

Immunoreactivity profiling of Anti-Chinese hamster ovarian host cell protein antibodies by isobaric labeled affinity purification-mass spectrometry reveals low-recovery proteins.

We evaluated the immunoreactivity profiles of eight commercial anti-host cell protein (anti-HCP) antibodies from different host animals and their antigens used for immunization by an isobaric labeled affinity purification-mass spectrometry (AP-MS) method. As a result, 34 proteins with high abundance but low recovery from harvest cell culture fluid were identified. Since they are likely to be underestimated in biopharmaceutical quality assessment, the features common to these proteins were investigated. Compared to other immunoprecipitated HCP proteins, proteins exhibiting lower molecular weight (ΔMW = -14600), lower isoelectric point (ΔpI = -0.86), and lower hydrophobicity (ΔGRAVY = -0.13) were enriched. This AP-MS method provides important information for HCP control strategies using immunological methods and is expected to contribute to the development of safe biopharmaceutics.

Dopamine dysfunction in depression: application of texture analysis to dopamine transporter single-photon emission computed tomography imaging.

Dopamine dysfunction has been associated with depression. However, results of recent neuroimaging studies on dopamine transporter (DAT), which reflect the function of the dopaminergic system, are inconclusive. The aim of this study was to apply texture analysis, a novel method to extract information about the textural properties of images (e.g., coarseness), to single-photon emission computed tomography (SPECT) imaging in depression. We performed SPECT using 123I-ioflupane to measure DAT binding in 150 patients with major depressive disorder (N = 112) and bipolar disorder (N = 38). The texture features of DAT binding in subregions of the striatum were calculated. We evaluated the relationship between the texture feature values (coarseness, contrast, and busyness) and severity of depression, and then examined the effects of medication and diagnosis on such relationship. Furthermore, using the data from 40 healthy subjects, we examined the effects of age and sex on the texture feature values. The degree of busyness of the limbic region in the left striatum linked to the severity of depression (p = 0.0025). The post-hoc analysis revealed that this texture feature value was significantly higher in both the severe and non-severe depression groups than in the remission group (p = 0.001 and p = 0.028, respectively). This finding remained consistent after considering the effect of medication. The effects of age and sex in healthy individuals were not evident in this texture feature value. Our findings imply that the application of texture analysis to DAT-SPECT may provide a state-marker of depression.

Motor Functional Characteristics in Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorders: A Systematic Review.

Background: The development of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASDs) has various influences on physical abilities. Identification of specific physical abilities of people with ADHD/ASDs as biomarkers for diagnosing these conditions is necessary. Therefore, in the present review, we aimed firstly to extract the difference in physical abilities of people with ADHD or ASDs compared to those of normal individuals. Secondly, we aimed to extract the specific physical ability characteristics for identifying potential diagnostic biomarkers in people with ADHD/ASDs. Methods: A systematic literature review was performed. The databases were searched for relevant articles on motor function deficits and characteristics of ADHD or ASD. Results: Forty-one cross-sectional studies and three randomized controlled trials were identified, comprising 33 studies of ADHD, 10 studies of ASDs, and 1 study of both ADHD and ASDs. The quality of studies varied. Three types of physical activities/exercises were identified, including coordinated movement, resistance-type sports, and aerobic-type sports. People with ADHD/ASDs generally exhibited poorer physical abilities for all types of activities, possibly because of low levels of physical activity. Specifically, we found temporal discoordination of movement in ADHD and integration or synchronization of separate movements in ASDs. Conclusion: Specific deficits in physical ability may be attributed to ADHD/ASDs. However, there is not enough research on the physical abilities of people with ADHD and ASDs to clarify the specific deficits. Investigation of specific motor functions that characterize ADHD/ASDs should be facilitated.

Hippocampal calcification and its effects on cognitive function and symptoms in dementia.

BACKGROUND: Hippocampal calcification (HC), highly prevalent in older people, has not attracted attention until recently. Despite its potential effects on cognition and behaviour, and its possible impact on the diagnosis and severity of dementia, it has not been investigated. This study aimed to evaluate the prevalence of HC and its influence on cognition and behavioural symptoms in patients with dementia. METHODS: Data from consecutive patients who visited a medical centre for dementia, for the first time between April 2016 and September 2018, were extracted and analysed. These data included the patients' demographics, the presence of HC and hippocampal thickness as measured on computed tomography, the diagnosis of dementia and its type, cognitive function measured using the Mini-Mental State Examination and the Clock Drawing Test, and the chief complaints or symptoms prompting the visit. RESULTS: A high incidence of HC (85/267 patients) was observed. There was no significant difference in the ages of patients with and without HC. Patients with HC had higher cognitive function than those without HC at their first visit. This result was contrary to our expectations as it was not explained by the chief complaints recorded at the first visit. CONCLUSIONS: Our study showed a high prevalence of HC in older patients with dementia. Patients with HC had better cognitive function than did those without HC during their first hospital visit. This study suggests that HC may not affect the cognitive functions related to dementia. However, further research is needed to evaluate the long-term consequences of dementia with HC.

Serine Racemase Expression by Striatal Neurons.

D-serine is synthesized by serine racemase (SR) and is a co-agonist at forebrain N-methyl-D-aspartate receptors (NMDARs). D-serine and SR are expressed primarily in neurons, but not in quiescent astrocytes. In this study, we examined the localization of D-serine and SR in the mouse striatum and the effects of genetically silencing SR expression in GABAergic interneurons (iSR-/-). iSR-/- mice had substantially reduced SR expression almost exclusively in striatum, but only exhibited marginal D-serine reduction. SR positive cells in the striatum showed strong co-localization with dopamine- and cyclic AMP-regulated neuronal phosphoprotein (DARPP32) in wild type mice. Transgenic fluorescent reporter mice for either the D1 or D2 dopamine receptors exhibited a 65:35 ratio for co-localization with D1and D2 receptor positive cells, respectively. These results indicate that GABAergic medium spiny neurons receiving dopaminergic inputs in striatum robustly and uniformly express SR. In behavioral tests, iSR-/- mice showed a blunted response to the hedonic and stimulant effects of cocaine, without affecting anxiety-related behaviors. Because the cocaine effects have been shown in the constitutive SR-/- mice, the restriction of the blunted response to cocaine to iSR-/- mice reinforces the conclusion that D-serine in striatal GABAergic neurons plays an important role in mediating dopaminergic stimulant effects. Results in this study suggest that SR in striatal GABAergic neurons is synthesizing D-serine, not as a glutamatergic co-transmitter, but rather as an autocrine whereby the GABAergic neurons control the excitability of their NMDARs by determining the availability of the co-agonist, D-serine.