Urinary Immunoglobulin G Is Associated with Deep and Infratentorial Cerebral Microbleeds in Stroke Patients.

BACKGROUND: Cerebral microbleeds (CMBs) detected on susceptibility-weighted imaging (SWI) are associated with cerebral small vessel disease. Chronic kidney disease and microalbuminuria have been associated with the presence of CMBs in stroke patients. Urinary immunoglobulin G (IgG) is measured to document glomerular injury; however, the relationship between urinary IgG and CMBs is unknown. METHODS: We retrospectively enrolled consecutive patients who had been admitted with transient ischemic attack (TIA) or ischemic stroke and identified those who had undergone SWI and a spot urine test. The location of CMBs was classified on magnetic resonance imaging as strictly lobar, deep/infratentorial (D/I), or mixed areas. We analyzed the association between urinary IgG and the presence and location of CMBs. RESULTS: We included 298 patients (86 female, median age 70 years, median eGFR 65.8 mL/min/1.73 m2). Positive urinary IgG and CMB results were found in 58 (19%) and 160 patients (54%), respectively. Urinary IgG positivity was significantly associated with CMBs compared with non-CMBs (28% vs. 9%, p < 0.001), and with D/I or mixed CMBs compared with non-D/I or mixed CMBs (34% vs. 10%, p < 0.001). Multivariate analysis revealed that urinary IgG and hypertension positivity were strongly associated with D/I or mixed CMBs (OR 3.479, 95% CI: 1.776-6.818, p < 0.001; OR 3.415, 95% CI: 1.863-6.258, p < 0.001). CONCLUSIONS: Urinary IgG was associated with the prevalence of D/I or mixed location CMBs in TIA or ischemic stroke patients. Our findings provide new insights into the association between urinary IgG and the distribution of CMBs.

Temporal dynamics of learning-promoted synaptic diversity in CA1 pyramidal neurons.

Although contextual learning requires plasticity at both excitatory and inhibitory (E/I) synapses in cornu ammonis 1 (CA1) neurons, the temporal dynamics across the neuronal population are poorly understood. Using an inhibitory avoidance task, we analyzed the dynamic changes in learning-induced E/I synaptic plasticity. The training strengthened GABAA receptor-mediated synapses within 1 min, peaked at 10 min, and lasted for over 60 min. The intracellular loop (Ser408-409) of GABAA receptor ß3 subunit was also phosphorylated within 1 min of training. As the results of strengthening of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor-mediated synapses, CA1 pyramidal neurons exhibited broad diversity of E/I synaptic currents within 5 min. Moreover, presynaptic glutamate release probability at basal dendrites also increased within 5 min. To further quantify the diversified E/I synaptic currents, we calculated self-entropy (bit) for individual neurons. The neurons showed individual levels of the parameter, which rapidly increased within 1 min of training and maintained for over 60 min. These results suggest that learning-induced synaptic plasticity is critical immediately following encoding rather than during the retrieval phase of the learning. Understanding the temporal dynamics along with the quantification of synaptic diversity would be necessary to identify a failure point for learning-promoted plasticity in cognitive disorders.-Sakimoto, Y., Kida, H., Mitsushima, D. Temporal dynamics of learning-promoted synaptic diversity in CA1 pyramidal neurons.

FABP3 in the Anterior Cingulate Cortex Modulates the Methylation Status of the Glutamic Acid Decarboxylase67 Promoter Region.

Polyunsaturated fatty acids (PUFAs) are essential for brain development and function. Increasing evidence has shown that an imbalance of PUFAs is associated with various human psychiatric disorders, including autism and schizophrenia. Fatty acid-binding proteins (FABPs), cellular chaperones of PUFAs, are involved in PUFA intracellular trafficking, signal transduction, and gene transcription. In this study, we show that FABP3 is strongly expressed in the GABAergic inhibitory interneurons of the male mouse anterior cingulate cortex (ACC), which is a component of the limbic cortex and is important for the coordination of cognitive and emotional behaviors. Interestingly, Fabp3 KO male mice show an increase in the expression of the gene encoding the GABA-synthesizing enzyme glutamic acid decarboxylase 67 (Gad67) in the ACC. In the ACC of Fabp3 KO mice, Gad67 promoter methylation and the binding of methyl-CpG binding protein 2 (MeCP2) and histone deacetylase 1 (HDAC1) to the Gad67 promoter are significantly decreased compared with those in WT mice. The abnormal cognitive and emotional behaviors of Fabp3 KO mice are restored by methionine administration. Notably, methionine administration normalizes Gad67 promoter methylation and its mRNA expression in the ACC of Fabp3 KO mice. These findings demonstrate that FABP3 is involved in the control of DNA methylation of the Gad67 promoter and activation of GABAergic neurons in the ACC, thus suggesting the importance of PUFA homeostasis in the ACC for cognitive and emotional behaviors.SIGNIFICANCE STATEMENT The ACC is important for emotional and cognitive processing. However, the mechanisms underlying its involvement in the control of behavioral responses are largely unknown. We show the following new observations: (1) FABP3, a PUFA cellular chaperone, is exclusively expressed in GABAergic interneurons in the ACC; (2) an increase in Gad67 expression is detected in the ACC of Fabp3 KO mice; (3) the Gad67 promoter is hypomethylated and the binding of transcriptional repressor complexes is decreased in the ACC of Fabp3 KO mice; and (4) elevated Gad67 expression and abnormal behaviors seen in Fabp3 KO mice are mostly recovered by methionine treatment. These suggest that FABP3 regulates GABA synthesis through transcriptional regulation of Gad67 in the ACC.

Differential temperature sensitivity of synaptic and firing processes in a neural mass model of epileptic discharges explains heterogeneous response of experimental epilepsy to focal brain cooling.

Experiments with drug-induced epilepsy in rat brains and epileptic human brain region reveal that focal cooling can suppress epileptic discharges without affecting the brain's normal neurological function. Findings suggest a viable treatment for intractable epilepsy cases via an implantable cooling device. However, precise mechanisms by which cooling suppresses epileptic discharges are still not clearly understood. Cooling experiments in vitro presented evidence of reduction in neurotransmitter release from presynaptic terminals and loss of dendritic spines at post-synaptic terminals offering a possible synaptic mechanism. We show that termination of epileptic discharges is possible by introducing a homogeneous temperature factor in a neural mass model which attenuates the post-synaptic impulse responses of the neuronal populations. This result however may be expected since such attenuation leads to reduced post-synaptic potential and when the effect on inhibitory interneurons is less than on excitatory interneurons, frequency of firing of pyramidal cells is consequently reduced. While this is observed in cooling experiments in vitro, experiments in vivo exhibit persistent discharges during cooling but suppressed in magnitude. This leads us to conjecture that reduction in the frequency of discharges may be compensated through intrinsic excitability mechanisms. Such compensatory mechanism is modelled using a reciprocal temperature factor in the firing response function in the neural mass model. We demonstrate that the complete model can reproduce attenuation of both magnitude and frequency of epileptic discharges during cooling. The compensatory mechanism suggests that cooling lowers the average and the variance of the distribution of threshold potential of firing across the population. Bifurcation study with respect to the temperature parameters of the model reveals how heterogeneous response of epileptic discharges to cooling (termination or suppression only) is exhibited. Possibility of differential temperature effects on post-synaptic potential generation of different populations is also explored.

Motor Training Promotes Both Synaptic and Intrinsic Plasticity of Layer II/III Pyramidal Neurons in the Primary Motor Cortex.

Motor skill training induces structural plasticity at dendritic spines in the primary motor cortex (M1). To further analyze both synaptic and intrinsic plasticity in the layer II/III area of M1, we subjected rats to a rotor rod test and then prepared acute brain slices. Motor skill consistently improved within 2 days of training. Voltage clamp analysis showed significantly higher α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-methyl-d-aspartate (AMPA/NMDA) ratios and miniature EPSC amplitudes in 1-day trained rats compared with untrained rats, suggesting increased postsynaptic AMPA receptors in the early phase of motor learning. Compared with untrained controls, 2-days trained rats showed significantly higher miniature EPSC amplitude and frequency. Paired-pulse analysis further demonstrated lower rates in 2-days trained rats, suggesting increased presynaptic glutamate release during the late phase of learning. One-day trained rats showed decreased miniature IPSC frequency and increased paired-pulse analysis of evoked IPSC, suggesting a transient decrease in presynaptic γ-aminobutyric acid (GABA) release. Moreover, current clamp analysis revealed lower resting membrane potential, higher spike threshold, and deeper afterhyperpolarization in 1-day trained rats-while 2-days trained rats showed higher membrane potential, suggesting dynamic changes in intrinsic properties. Our present results indicate dynamic changes in glutamatergic, GABAergic, and intrinsic plasticity in M1 layer II/III neurons after the motor training.

Astrocyte-expressed FABP7 regulates dendritic morphology and excitatory synaptic function of cortical neurons.

Fatty acid binding protein 7 (FABP7) expressed by astrocytes in developing and mature brains is involved in uptake and transportation of fatty acids, signal transduction, and gene transcription. Fabp7 knockout (Fabp7 KO) mice show behavioral phenotypes reminiscent of human neuropsychiatric disorders such as schizophrenia. However, direct evidence showing how FABP7 deficiency in astrocytes leads to altered brain function is lacking. Here, we examined neuronal dendritic morphology and synaptic plasticity in medial prefrontal cortex (mPFC) of Fabp7 KO mice and in primary cortical neuronal cultures. Golgi staining of cortical pyramidal neurons in Fabp7 KO mice revealed aberrant dendritic morphology and decreased spine density compared with those in wild-type (WT) mice. Aberrant dendritic morphology was also observed in primary cortical neurons co-cultured with FABP7-deficient astrocytes and neurons cultured in Fabp7 KO astrocyte-conditioned medium. Excitatory synapse number was decreased in mPFC of Fabp7 KO mice and in neurons co-cultured with Fabp7 KO astrocytes. Accordingly, whole-cell voltage-clamp recording in brain slices from pyramidal cells in the mPFC showed that both amplitude and frequency of action potential-independent miniature excitatory postsynaptic currents (mEPSCs) were decreased in Fabp7 KO mice. Moreover, transplantation of WT astrocytes into the mPFC of Fabp7 KO mice partially attenuated behavioral impairments. Collectively, these results suggest that astrocytic FABP7 is important for dendritic arbor growth, neuronal excitatory synapse formation, and synaptic transmission, and provide new insights linking FABP7, lipid homeostasis, and neuropsychiatric disorders, leading to novel therapeutic interventions.

Spatiotemporal characteristics of surround suppression in primary visual cortex and lateral geniculate nucleus of the cat.

In the primary visual cortex (V1), a neuronal response to stimulation of the classical receptive field (CRF) is predominantly suppressed by a stimulus presented outside the CRF (extraclassical receptive field, ECRF), a phenomenon referred to as ECRF suppression. To elucidate the neuronal mechanisms and origin of ECRF suppression in V1 of anesthetized cats, we examined the temporal properties of the spatial extent and orientation specificity of ECRF suppression in V1 and the lateral geniculate nucleus (LGN), using stationary-flashed sinusoidal grating. In V1, we found three components of ECRF suppression: (1) local and fast, (2) global and fast, and (3) global and late. The local and fast component, which resulted from within 2° of the boundary of the CRF, started no more than 10 ms after the onset of the CRF response and exhibited low specificity for the orientation of the ECRF stimulus. These spatiotemporal properties corresponded to those of geniculate ECRF suppression, suggesting that the local and fast component of V1 is inherited from the LGN. In contrast, the two global components showed rather large spatial extents ∼5° from the CRF boundary and high specificity for orientation, suggesting that their possible origin is the cortex, not the LGN. Correspondingly, the local component was observed in all neurons of the thalamocortical recipient layer, while the global component was biased toward other layers. Therefore, we conclude that both subcortical and cortical mechanisms with different spatiotemporal properties are involved in ECRF suppression.

Hybrid laparoscopic complete untinatectomy of pancreas by Shuriken shaped umbilicoplasty with sliding windows method.

In this study, we demonstrated the complete resection of untinate process that was performed by the hybrid laparoscopic surgery using our original new technique of Shuriken shaped umbilicoplasty with sliding window`s method. A 70-year-old weman was hospitalized for surgery of intraductal papillary mucinous neoplasm located in the uncinate process of pancreas. Under general anesthesia, a Shuriken shaped umbilical skin incision was made by 7 cm in horizontal and 4cm longitudinal width with 3cm round skin incision. The intermediate skin between outside and inside skin incision was removed. Subcutaneous tissue around the umbilicus and the upper abdominal subcutaneous region was dissected, and the 8cm of upper abdominal minilaparotomy was performed. The complete resection of untinate process was performed by hybrid laparoscopic procedure with the hand-assisted or the laparo-assisted manner. The umbilicoplasty of only 3cm round skin wound was made by the reefing of subcutaneous suture with 5-0 absorbable suture. The patient suffered from pancreas leakage from pancreas stump, however it was recovered spontaneously. Our new procedure could be used for PD, DP, and Major hepatectomy with the hybrid laparoscopic procedure. It might be considered that our method is good for both cosmetic and safety benefits in HPB surgery.

[A case of severe enteritis induced by adjuvant chemotherapy for colon cancer].

A 77-year-old man underwent surgery for sigmoid colon cancer. He was diagnosed with Stage IIIa colon cancer; there- fore, we initiated oral administration of adjuvant chemotherapy comprising uracil/tegafur(UFT)plus Leucovorin(LV). However, chemotherapy was stopped after 21 days because of fatigue and diarrhea. He recovered after 3 weeks, and we administered the same regimen with a dose reduction. However, he again experienced fatigue and diarrhea after 20 days; therefore, chemotherapy was discontinued. Subsequently, he was hospitalized 8 times for conditions such as diarrhea, hypoalbuminemia, and fever. Computed tomography revealed thickening of the transverse colonic wall and colonoscopy revealed colitis, which we believe was induced by UFT plus LV. Twelve months after the last chemotherapy session, he was diagnosed with Clostridium difficile colitis. Therefore, we initiated the oral administration of vancomycin, which resulted in rapid recovery from colitis. However, he developed liver metastasis and died 29 months after the initiation of chemotherapy. We believe that this severe case of intractable colitis was caused by UFT plus LV. Therefore, we report this case with a review of the literature on enteritis induced by fluorouracil-based anticancer agents in Japan.

Focal brain cooling suppresses spreading depolarization and reduces endothelial nitric oxide synthase expression in rats.

This study aimed to investigate the effects of focal brain cooling (FBC) on spreading depolarization (SD), which is associated with several neurological disorders. Although it has been studied from various aspects, no medication has been developed that can effectively control SD. As FBC can reduce neuronal damage and promote functional recovery in pathological conditions such as epilepsy, cerebral ischemia, and traumatic brain injury, it may also potentially suppress the onset and progression of SD. We created an experimental rat model of SD by administering 1 M potassium chloride (KCl) to the cortical surface. Changes in neuronal and vascular modalities were evaluated using multimodal recording, which simultaneously recorded brain temperature (BrT), wide range electrocorticogram, and two-dimensional cerebral blood flow. The rats were divided into two groups (cooling [CL] and non-cooling [NC]). Warm or cold saline was perfused on the surface of one hemisphere to maintain BrT at 37°C or 15°C in the NC and CL groups, respectively. Western blot analysis was performed to determine the effects of FBC on endothelial nitric oxide synthase (eNOS) expression. In the NC group, KCl administration triggered repetitive SDs (mean frequency = 11.57/h). In the CL group, FBC increased the duration of all KCl-induced events and gradually reduced their frequency. Additionally, eNOS expression decreased in the cooled brain regions compared to the non-cooled contralateral hemisphere. The results obtained by multimodal recording suggest that FBC suppresses SD and decreases eNOS expression. This study may contribute to developing new treatments for SD and related neurological disorders.

Thin aortic arch plaque is associated with the development of atrial fibrillation for embolic stroke of undetermined source in patients with an insertable cardiac monitor.

BACKGROUND AND OBJECTIVE: This study's objective is to investigate whether mild aortic arch plaque is associated with the development of atrial fibrillation (AF) in stroke patients with embolic stroke of undetermined source (ESUS) during the first year following the implantation of an insertable cardiac monitor (ICM). METHODS: The participants in this cross-sectional observational study were consecutive patients with ESUS, even after transesophageal echocardiography. We assessed the relationship between the thickness of the participants' aortic arch plaque and AF detected after ICM implantation. RESULTS: Of the 50 consecutive patients with ESUS enrolled in this study, 12 (24%) developed AF. We observed that thicker aortic arch plaque was associated with undetected AF (2.3 mm vs. 1.2 mm, p < 0.001). Aortic arch plaque thickness was independent associated with undetected AF (OR 54.00, 95% CI 2.706-1077.544, p = 0.009). When the cut-off value for aortic arch plaque thickness was 1.8 mm, the sensitivity and specificity were 71.1% and 91.7%, respectively (95% CI = 0.75-0.98, p < 0.001). Also, patients having both aortic arch plaque with a thickness < 1.8 mm and a CHADS2 score ≥ 4 were more likely to have detectable AF than no AF (88% vs. 12%, p < 0.001). CONCLUSION: A thinner aortic arch plaque was associated with the development of AF. Patients with mild aortic plaques below 4 mm but ≥1.8 mm in thickness and without other high-risk features are less likely to have paroxysmal AF on ICM, and these plaques may be a possible source of embolism for their strokes.

Effects and safety of high-frequency rTMS in subacute ischemic stroke patients.

OBJECTIVE: Although high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has shown benefits in chronic stroke, its application in subacute ischemic stroke remains underexplored. This study aims to investigate the effects and safety of lesion-side HF-rTMS in subacute ischemic stroke. METHODS: Prospective lesion-side HF-rTMS was conducted on consecutive ischemic stroke patients within 3 days of onset from February 2019 to June 2022. Inclusion criteria required persistent paralysis (NIHSS score ≥ 1 for at least 7 days). Exclusion criteria comprised cortical infarction, disturbance of consciousness, and age over 80 years. A conventional rehabilitation group meeting the same criteria from June 2015 to January 2019 served as a comparison. We compared the two groups regarding clinical background and outcome. We also evaluated incidence of epilepsy and exacerbation of the NIHSS score in the rTMS group. RESULTS: Seventy-eight patients participated, with 50% in the HF-rTMS group. Median time from onset to HF-rTMS initiation was 9 (IQR 7-12) days. A favorable outcome (modified Rankin Scale score 0-2) at 3 months was more frequent in the rTMS group (80% vs. 44%, p = 0.002). HF-rTMS was independently associated with a favorable outcome at 3 months (OR = 5.60, 95% CI = 1.53-20.50, p = 0.009). No cases of epilepsy or exacerbation of NIHSS score were observed. CONCLUSIONS: HF-rTMS demonstrates potential effectiveness and safety in subacute ischemic stroke patients.

Urinary Immunoglobulin G Is a Novel Biomarker for Atherosclerotic Burden in Mild Acute Ischemic Stroke Patients.

AIMS: Urinary immunoglobulin G (IgG) may be a stronger marker of atherosclerosis than microalbuminuria are because urinary IgG reflects proteinuria level and size-selectivity loss. Microalbuminuria-not urinary IgG-is associated with mild acute ischemic stroke (MAIS). METHODS: Using the Jikei University School of Medicine Stroke Registry, we selected and screened patients with symptomatic acute ischemic stroke (onset-to-door time ≤ 24 h). The exclusion criteria were (1) on-admission NIHSS scores ＞10, (2) a modified Rankin Scale (mRS) score ≥ 2 prior to stroke onset, (3) incomplete data (no urinalysis ≤ 3 days after admission or no mRS score at 90 days from stroke onset), and (4) an active malignancy. Patients at 90 days post-discharge were divided into those with favorable mRS scores of 0-1 and those with unfavorable mRS scores of 2-6. Clinical backgrounds were compared for (1) patients with positive and negative urinary IgG results, and (2) patients with favorable and unfavorable outcomes. RESULTS: Of our study's 210 patients (164=male, median age=68, median eGFR=53.2 ml/min/1.73 m2), 30 (14%) presented with positive urinary IgG, which was associated with cardiovascular risk factors. Higher BNP, higher D-dimer, lower eGFR, and higher CAVI were associated with higher positive urinary IgG. The favorable group, comprising 155 (74%) patients, had higher negative urinary IgG than the unfavorable group (89% vs 76%, P=0.026). No statistical difference emerged regarding microalbuminuria (29% vs 29%, P=1.000). CONCLUSION: In MAIS, urinary IgG was associated with both the presence of atherosclerosis and an unfavorable outcome at 90 days after stroke onset.

Reduced Likelihood of Infarction in Crescendo Transient Ischemic Attack Caused by Vasculitic Middle Cerebral Artery Stenosis.

A 53-year-old woman was admitted to our hospital because of increasingly frequent transient speech disturbance and left upper limb weakness. Brain magnetic resonance imaging and angiography revealed multiple intracranial stenoses, including the proximal right middle cerebral artery (MCA), without evidence of infarction. The diagnosis of primary angiitis of the central nervous system was established based on circumferential vascular wall thickening with contrast enhancement observed in the right MCA. Following the administration of dual antiplatelet therapy and intravenous methylprednisolone pulse therapy, the patient experienced complete cessation of symptoms, and the stenosis gradually improved without infarction. The risk of infarct development in crescendo transient ischemic attacks may differ between inflammatory vascular stenosis and atherosclerosis.

Follow-Up Diffusion-Weighted Image Reveals Delayed Appearance of Ischemic Lesions in Suspected Transient Ischemic Attack.

INTRODUCTION: In patients suspected of transient ischemic attack (TIA), it is not uncommon to find no lesion on the diffusion-weighted image (DWI) on admission but a delayed appearance on the follow-up DWI. METHODS: Enrolled patients met the following criteria: (1) MRI performed within 24 hours of onset and seven days after admission; (2) National Institutes of Health Stroke Scale (NIHSS) score ≦4 on admission; (3) pre-stroke modified Rankin scale (mRS) score of 0-1. Patients were divided as follows: no lesion on the first DWI and a new lesion on the second DWI (delayed-specified ischemic stroke; DSIS); and no lesion on either the first or second DWI (well-screened TIA; WSTIA). We compared both groups regarding the clinical background and the outcome at three months. RESULTS: We identified 144 cases (male 70%; median age 64 years; DSIS, n=34) between October 2012 and March 2019. DSIS was older (71 vs. 60 years, p=0.006) and had a higher NIHSS score on admission (1 vs. 0, p=0.041), a higher rate of large vessel occlusion (LVO) (17% vs. 2%, p=0.008), and symptom duration over one hour (82% vs. 64%, p=0.041). A favorable outcome mRS score of 0-1 at three months was less frequent in DSIS (85% vs. 96%, p=0.004). Age/10 (OR 1.62, 95%CI 1.17-2.24; p=0.004) and LVO (OR 10.84, 95%CI 1.87-63.06; p=0.008) were independent factors for DSIS. CONCLUSIONS: In suspected TIA with age or LVO but no lesion in the initial DWI, the second DWI should be considered to identify the delayed appearance of an ischemic stroke.

A critical period for learning and plastic changes at hippocampal CA1 synapses.

Postnatal development of hippocampal function has been reported in many mammalian species, including humans. To obtain synaptic evidence, we analyzed developmental changes in plasticity after an inhibitory avoidance task in rats. Learning performance was low in infants (postnatal 2 weeks) but clearly improved from the juvenile period (3-4 weeks) to adulthood (8 weeks). One hour after the training, we prepared brain slices and sequentially recorded miniature excitatory postsynaptic currents (mEPSCs) and inhibitory postsynaptic currents (mIPSCs) from the same hippocampal CA1 neuron. Although the training failed to affect the amplitude of either mEPSCs or mIPSCs at 2 weeks, it increased mEPSC, but not mIPSC, amplitude at 3 weeks. At 4 weeks, the training had increased the amplitude of both mEPSCs and mIPSCs, whereas mIPSC, but not mEPSC, amplitude was increased at 8 weeks. Because early-life physiological functions can affect performance, we also evaluated sensory-motor functions together with emotional state and found adequate sensory/motor functions from infancy to adulthood. Moreover, by analyzing performance of rats in multiple hippocampal-dependent tasks, we found that the developmental changes in the performance are task dependent. Taken together, these findings delineate a critical period for learning and plastic changes at hippocampal CA1 synapses.

The meaning of non-culprit stenosis in hyperacute stroke with large vessel occlusion.

BACKGROUND AND PURPOSE: To diagnose atherosclerotic occlusion mechanism in acute ischemic stroke patients with large vessel occlusion prior to revascularization therapy is challenging. The aim was to verify the relationship between atherosclerotic occlusion and non-culprit stenosis detected in urgent neuroimaging prior to interventional procedure. MATERIALS AND METHODS: This study collected hyperacute stroke with large vessel occlusion, who underwent revascularization therapy (intravenous thrombolysis, thrombectomy, or both). An atherosclerotic occlusion was defined as an occlusion that did not recanalize or had residual stenosis at the initially occluded lesion, ensured in the second angiographic imaging performed after 1 week. The remaining patients who did not fulfill the definition of atherosclerotic occlusion was classified as embolic occlusion. A non-culprit stenosis was defined as a ≥ 50%-99% stenosis located other than the culprit occluded artery. Logistic regression analyses were performed to determine the factors independently associated with atherosclerotic occlusion. RESULTS: A total of 162 patients (104 men, median age 76 years old) were enrolled in our study. Forty one patients (25%) was atherosclerotic occlusion. Non-culprit stenosis was frequently observed in the atherosclerotic occlusion group than the embolic occlusion group (68% vs. 26%, P < 0.001). The presence of non-culprit stenosis was independently associated with atherosclerotic occlusion (OR, 11.00; 95% CI, 3.96-30.52; P < 0.001). CONCLUSION: In hyperacute stroke receiving endovascular therapy, non-culprit stenosis identification may be needed in order to perform an adequate revascularization, especially for atherosclerotic occlusion.

Effects and safety of high-frequency rTMS in acute intracerebral hemorrhage patients: A pilot study.

OBJECTIVE: Although high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) in chronic intracerebral hemorrhage (ICH) is beneficial, it has been poorly investigated in rTMS for acute ICH. Our aim is to investigate the effects and safety of rTMS in acute spontaneous ICH. METHODS: We prospectively performed HF-rTMS on consecutive patients with ICH within 24 h from onset between April 2019 and August 2021. The inclusion criterion was (1) persistent paralysis, with an NIHSS scale of 1 or higher for at least 3 days after onset. The exclusion criteria were (1) cortical, subcortical, and cerebellar ICH, (2) disturbance of consciousness, and (3) over 80 years of age. For the purpose of comparison, we used a conventional rehabilitation group whose patients met the same criteria between April 2016 and March 2019. We evaluated incidence of epilepsy and exacerbation of the NIHSS score in the rTMS group. We also compared the two groups regarding clinical background and outcome. RESULTS: Enrolled in the study were a total of 44 patients. Of the patients, 22 (50%) were in the rTMS group. The median (IQR) time from onset to the start of rTMS was 9 (6-12) days. There were no cases of epilepsy or exacerbation of NIHSS after the start of rTMS. Favorable outcome (modified Rankin Scale score of between 0 and 2) at 3 months was frequently observed in the rTMS group (73% vs 27%, p = 0.006). HF-rTMS was independently associated with favorable outcome at 3 months (OR = 11.5, 95% CI = 2.194-60.447, p = 0.004). CONCLUSIONS: HF-rTMS may be safe and effective in acute ICH patients.

Temporal properties of spatial frequency tuning of surround suppression in the primary visual cortex and the lateral geniculate nucleus of the cat.

In primary visual cortex (V1) neurons, a stimulus placed in the extraclassical receptive field suppresses the response to a stimulus within the classical receptive field (CRF), a phenomenon referred to as surround suppression. The aim of the present study was to elucidate the mechanisms of surround suppression in V1. Using stationary-flashed sinusoidal grating as stimuli, we observed temporal changes of surround suppression in V1 and the lateral geniculate nucleus (LGN) and of the response to CRF stimulation in V1. The spatial frequency (SF) tuning of surround suppression in V1 neurons changed over time after the stimulus onset. In the early phase (< 50 ms), the SF tuning was low-pass, but later became band-pass that tuned to the optimal SF in response to CRF stimulation. On the other hand, the SF tuning of CRF responses in V1 was band-pass throughout the response time whereas the SF peak shifted slightly toward high SF. Thus, SF tuning properties of the CRF response dissociated from that of surround suppression in V1 only in the early phase. We also confirmed that the temporal changes of the SF tuning of surround suppression in the LGN occurred in the same direction as surround suppression in V1, but the shift from low-pass to band-pass SF tuning started later than that in V1. From these results, we suggest that subcortical mechanisms contribute to early surround suppression in V1, whereas cortical mechanisms contribute to late surround suppression.

Proximodistal Heterogeneity in Learning-promoted Pathway-specific Plasticity at Dorsal CA1 Synapses.

Contextual learning requires the delivery of AMPA receptors to CA1 synapses in the dorsal hippocampus. However, proximodistal heterogeneity of pathway-specific plasticity remains unclear. Here, we examined the proximodistal heterogeneity in learning-induced plasticity at the CA1 synapses with inputs from the entorhinal cortex layer III (ECIII) or from CA3. We subjected male rats to an inhibitory avoidance task and prepared acute hippocampal slices for whole-cell patch clamp experiments, where we stimulated ECIII-CA1 or CA3-CA1 input fibers to analyze evoked excitatory postsynaptic currents (EPSCs). Compared to untrained controls, trained rats exhibited higher AMPA/NMDA current ratios at CA3-CA1 synapses of proximal and intermediate, but not distal CA1 neurons, which suggested that region-specific plasticity occurred after learning. Moreover, trained rats exhibited higher AMPA/NMDA current ratios at ECIII-CA1 synapses of intermediate and distal, but not proximal CA1 neurons. These findings suggested the presence of proximodistal heterogeneity in pathway-specific postsynaptic plasticity. Regarding presynaptic plasticity, training slightly, but significantly increased the paired-pulse ratios of CA3-CA1 synapses of proximal and intermediate, but not distal CA1 neurons. Moreover, trained rats exhibited higher paired-pulse ratios at ECIII-CA1 synapses of intermediate and distal, but not proximal CA1 neurons, which suggested region-specific presynaptic plasticity. Finally, learning was clearly prevented by the bilateral microinjection of a plasticity blocker in the proximal or intermediate, but not distal CA1 subfields, which suggested functional heterogeneity along the proximodistal axis. Understanding region- and pathway-specific plasticity at dorsal CA1 synapses could aid in controlling encoded memory.