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Focuses on a study which developed a novel technique that allowed reversible suppression of glutamatergic neurotransmission in the cerebellar network. Lines of transgenic mice; Element designed in the TeNT mice; Composition of an approach used to understanding mechanisms underlying information processing and integration in the neural circuit.

Summary: We present the case of a 50-year-old Japanese woman who was transferred to our hospital with a 2-day history of fever, sore throat, and malaise. She was diagnosed with acromegaly 9 months ago while being treated for diabetic ketoacidosis, for which she underwent pituitary surgery. She was diagnosed with hypopituitarism postoperatively and was prescribed hydrocortisone and levothyroxine. Her glycemic control was good on metformin. Tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza were positive in the emergency room. Other laboratory findings included thyrotoxicosis (free T3: 9.13 pg/mL; free T4: 3.64 ng/dL; and thyroid-stimulating hormone (TSH): <0.01 μIU/mL) and a high C-reactive protein (CRP) level (3.84 mg/dL). The test for the TSH receptor antibody was negative. She had no apparent goiter and reported no tenderness in response to thyroid palpation. 99m-Technetium scintigraphy revealed decreased tracer uptake. Ultrasonography showed no hypoechoic lesions. Her thyrotoxicosis spontaneously resolved after 6 weeks. Although both anti-thyroglobulin antibody (TgAb) and anti-thyroid peroxidase antibody (TPOAb) were negative 9 months ago, TgAb was positive at admission. The test for TPOAb became positive 6 weeks later. These findings were suggestive of painless thyroiditis. In this patient, painless thyroiditis was believed to be caused by SARS-CoV-2 and influenza infections. Screening tests of thyroid function in patients with viral infections such as SARS-CoV-2 or influenza are recommended, even when thyroid gland pain or tenderness is not observed., Learning Points: We describe a case of painless thyroiditis associated with SARS-CoV-2 and influenza infections. Although a few cases of painless thyroiditis associated with COVID-19 have been reported, no cases of painless thyroiditis associated with influenza have been reported. In this case, thyrotoxicosis developed immediately after the viral infection. In addition, tests for anti-thyroglobulin antibody and anti-thyroid peroxidase antibody were negative before the onset of symptoms. Tests for the former became positive at the time of onset of symptoms, whereas tests for the latter became positive several weeks after the onset of symptoms. Patients with viral infections such as SARS-CoV-2 and influenza, who had no goiter or thyroid tenderness, may develop painless thyroiditis; screening tests for thyroid function are recommended.

Aldosterone secretion in primary aldosteronism (PA) is often regulated by adrenocorticotropic hormone (ACTH) in addition to its autonomous secretion. However, the clinical characteristics and risk of cardiovascular and cerebrovascular (CCV) events in PA patients with aldosterone responsiveness to ACTH stimulation remain unclear. This study aimed to investigate the prevalence of CCV events in PA patients with high aldosterone responsiveness to ACTH stimulation. A retrospective cross-sectional study was conducted as part of the Japan Primary Aldosteronism Study/Japan Rare Intractable Adrenal Disease project. PA patients with adrenal venous sampling (AVS) between January 2006 and March 2019 were enrolled. The ACTH-stimulated plasma aldosterone concentration (PAC) of the inferior vena cava during AVS was used to evaluate aldosterone responsiveness to ACTH. We analyzed the relationship between responsiveness and previous CCV events. Logistic regression analysis demonstrated that the ΔPAC (the difference between the PAC measurements before and after ACTH stimulation) significantly increased the odds of previous CCV events in PA patients after adjusting for classical CCV event risk factors, baseline PAC and duration of hypertension (relative PAC: odds ratio [OR], 2.896; 95% confidence interval [CI], 0.989-8.482; ΔPAC: OR, 2.344; 95% CI, 1.149-4.780; ACTH-stimulated PAC: OR, 2.098; 95% CI, 0.694-6.339). This study clearly demonstrated that aldosterone responsiveness to ACTH is closely related to previous CCV events. The responsiveness of the PAC to ACTH could be useful in predicting CCV event risk.Registration Number in UMIN-CTR is UMIN000032525.

Hyperkalemia is developed in a part of patients with aldosterone-producing adenoma (APA) after adrenalectomy, suspected to be due to the insufficiency of aldosterone secretion. The purpose of this study is to determine the frequency and characteristics of prolonged postoperative hypoaldosteronism (PPHA) using chemiluminescent enzyme immunoassay (CLEIA). We studied 58 patients with APA with long time after adrenalectomy and whose PAC was measured using a CLEIA kit. The PAC value measured using CLEIA was significantly lower than that of using RIA between two consecutive visits before and after the shift of measuring method of PAC (median [interquantile range], 123.0 [99.8-164.0] vs. 39.5 [15.8-64.2] pg/mL, p < 0.01). PAC was below the minimum limit of quantification (4.0 pg/mL) of the CLEIA kit at least once in nine patients (15.5%) who had PPHA. The PPHA group were older (mean ± standard deviation, 61.3 ± 8.5 vs. 50.5 ± 10.1 years, p < 0.01) and had lower eGFR (60.3 ± 14.0 vs. 82.3 ± 22.8 mL/min/1.73 m 2 , p < 0.01) than the non-PPHA group. The frequency of postoperative hyperkalemia (maximum serum potassium >5.5 mEq/L) was higher in the PPHA group than in the non-PPHA group (55.6% vs. 8.2%, p < 0.01). In conclusion, a few patients with APA long time after adrenalectomy had unmeasurable PAC using CLEIA. PPHA is likely to develop in patients with APA after adrenalectomy who are older and have impaired renal function. Additionally, PPHA is related to the occurrence of postoperative hyperkalemia.

In Japan, the standard method for measuring plasma aldosterone concentration (PAC) for primary aldosteronism (PA) diagnosis was changed from radioimmunoassay (RIA) to a novel chemiluminescent enzyme immunoassay (CLEIA). The purpose of this study is to simulate the possible impact of the change on PA diagnosis. This retrospective study assessed 2,289 PA patients. PACs measured by conventional RIA were transformed to estimated PACs (CLEIA) as follows: RIA (pg/mL) = 1.174 × CLEIA (pg/mL) + 42.3. We applied the estimated PAC (CLEIA) to the conventional cut-off of aldosterone-to-renin activity ratio ≥200 for screening and captopril challenge test (CCT) and PAC ≥60 pg/mL for saline infusion test (SIT). Application of the estimated PAC to screening and confirmatory tests decreased the number of PA diagnoses by 36% (743/2,065) on CCT and 52% (578/1,104) on SIT (discrepant cases). Among the discrepant cases, 87% (548/628) of CCT and 87% (452/522) of SIT were bilateral on adrenal venous sampling (AVS). Surgically treatable aldosterone-producing adenomas (APAs) were observed in 6% (36/579) and 5% (23/472) of discrepant cases on CCT and SIT, respectively; most were characterized by hypokalemia and/or adrenal nodule on CT imaging. Application of the PAC measured by the novel CLEIA to conventional cut-offs decreases the number of PA diagnoses. Although most discrepant cases were bilateral on AVS, there are some APA cases that were characterized by hypokalemia and/or adrenal tumor on CT. Further studies which evaluate PACs measured by both RIA and CLEIA for each patient are needed to identify new cut-offs for PAC measured by CLEIA.

Context: Adrenal venous sampling (AVS) is the current criterion standard lateralization technique in primary aldosteronism (PA). Japanese registry data found that 30% of patients with unilateral PA did not undergo adrenalectomy, but the reasons for this and whether the same pattern is seen internationally are unknown., Objective: To assess the rate of AVS-guided adrenalectomy across an international cohort and identify factors that resulted in adrenalectomy not being performed in otherwise eligible patients., Design, Setting, and Participants: Retrospective, multinational, multicenter questionnaire-based survey of management of PA patients from 16 centers between 2006 and 2018., Main Outcome Measures: Rates of AVS implementation, AVS success rate, diagnosis of unilateral PA, adrenalectomy rate, and reasons why adrenalectomy was not undertaken in patients with unilateral PA., Results: Rates of AVS implementation, successful AVS, and unilateral disease were 66.3%, 89.3% and 36.9% respectively in 4818 patients with PA. Unilateral PA and adrenalectomy rate in unilateral PA were lower in Japanese than in European centers (24.0% vs 47.6% and 78.2% vs 91.4% respectively). The clinical reasoning for not performing adrenalectomy in unilateral PA were more likely to be physician-derived in Japan and patient-derived in Europe. Physician-derived factors included non-AVS factors, such as good blood pressure control, normokalemia, and the absence of adrenal lesions on imaging, which were present before AVS., Conclusion: Considering the various unfavorable aspects of AVS, stricter implementation and consideration of surgical candidacy prior to AVS will increase its diagnostic efficiency and utility., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

We report a case of Erdheim-Chester disease (ECD) complicated with central diabetes insipidus that was refractory to several treatments. A 58-year-old female suffered from fatigue, fever, thirst, polyuria, leg pain, xanthoma of her upper eyelids, and disturbance of consciousness. Computed tomography (CT) imaging showed infiltration of perivascular soft tissue surrounding the aorta, hydronephrosis, and sclerotic lesions of the femurs and tibias. Magnetic resonance imaging showed the enhancement of expansile pachymeningeal lesions. A water deprivation test revealed the presence of central diabetes insipidus. The results of skin and bone marrow biopsies were consistent with ECD. The patient was treated with prednisone (30 mg daily) and interferon-α (6 mIU three times/week). The perivascular soft tissue showed a slight improvement, but she experienced cerebral hemorrhage 4 and 8 months later. Subsequently, she was treated biweekly with IV tocilizumab (8 mg/kg). Although her clinical symptoms improved, enlargement of the meningeal tumor and hydrocephalus led to disturbance of consciousness 6 months later. After the surgical debulking of the intracranial lesion, she was treated with two cycles of IV cladribine (0.12 mg/kg for 5 d). She had a transient clinical improvement but developed central nervous system disease marked by progressive neurological symptoms.

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension. Adrenal vein sampling (AVS) is an established method for finding patients with the unilateral subtype of PA, for which adrenalectomy is an applicable treatment. In this study, we analyzed a large database of patients with PA who underwent adrenal vein sampling, to investigate the sex differences in the impact of age at diagnosis on the subtype and cause of PA. In 2122 patients, women with the unilateral subtype were younger than men with the same subtype and women with the bilateral subtype. Younger age and older age were associated with unilateral PA in women and men, respectively. After stratification by tertiles of age, there was a trend of decreased and increased incidence of unilateral PA with aging in women and men, respectively. Male sex was a predictor of unilateral PA in middle-aged and older patients but not in younger patients. We also found that obesity, a known factor associated with idiopathic hyperaldosteronism, was positively associated with bilateral PA in younger patients but not in older patients. These findings suggest that the proportion of operable patients with unilateral PA differs depending on the combination of sex and age, and that other than obesity, the cause of PA is also associated with the bilateral subtype in older patients.

Background: Adrenal venous sampling (AVS) is essential for identifying a surgically curable form of primary aldosteronism. Adrenocorticotropic hormone (ACTH) infusion or bolus has been reported to improve the success rate of AVS, although the effects on lateralization and its outcomes in unilateral primary aldosteronism are unclear., Methods: The success rate and lateralization indices were examined in a cohort of 2197 Japanese patients with primary aldosteronism from 28 centres who underwent AVS. Outcomes were analysed in 267 patients with aldosterone-producing adenomas (APAs)., Results: ACTH loading during AVS improved the success rate from 67 to 89%, while lateralization indices decreased from 62 to 28%. Bolus, bolus along with continuous infusion or continuous infusion of ACTH did not affect both indices. The absence of clinical success (i.e. unchanged or increased blood pressure) was 33% and absence of biochemical success (persistent hypokalaemia or persistently raised aldosterone-to-renin ratio, or both) was 15%. The clinical and biochemical success rates did not differ between the three groups [lateralization index >2 in basal condition (LIb) and lateralization index >4 after ACTH loading (lateralization indices), and LIb >2 + lateralization indices<4, LIb<2+lateralization indices>4]. The three groups (LIb>4+lateralization indices>4, LIb>4+lateralization indices<4 and LIb<4+lateralization indices>4) did not show any significant differences of clinical and biochemical outcome., Conclusion: ACTH loading during AVS improved the success rate but decreased laterality. ACTH did not affect the clinical and biochemical outcomes in APA patients. These data showed that the use of ACTH during AVS was helpful for improving the success rate, but did not contribute to better outcomes.

There have been several clinical studies examining the factors associated with cardiovascular disease (CVD) in patients with primary aldosteronism (PA); however, their results have left it unclear whether CVD is affected by the plasma aldosterone concentration or hypokalemia. We assessed the PA database established by the multicenter JPAS (Japan Primary Aldosteronism Study) and compared the prevalence of CVD among patients with PA with that among age-, sex-, and blood pressure-matched essential hypertension patients and participants with hypertension in a general population cohort. We also performed binary logistic regression analysis to determine which parameters significantly increased the odds ratio for CVD. Of the 2582 patients with PA studied, the prevalence of CVD, including stroke (cerebral infarction, cerebral hemorrhage, or subarachnoid hemorrhage), ischemic heart disease (myocardial infarction or angina pectoris), and heart failure, was 9.4% (stroke, 7.4%; ischemic heart disease, 2.1%; and heart failure, 0.6%). The prevalence of CVD, especially stroke, was higher among the patients with PA than those with essential hypertension/hypertension. Hypokalemia (K + ≤3.5 mEq/L) and the unilateral subtype significantly increased adjusted odds ratios for CVD. Although aldosterone levels were not linearly related to the adjusted odds ratio for CVD, patients with plasma aldosterone concentrations ≥125 pg/mL had significantly higher adjusted odds ratios for CVD than those with plasma aldosterone concentrations <125 pg/mL. Thus, patients with PA seem to be at a higher risk of developing CVD than patients with essential hypertension. Moreover, patients with PA presenting with hypokalemia, the unilateral subtype, or plasma aldosterone concentration ≥125 pg/mL are at a greater risk of CVD and have a greater need for PA-specific treatments than others., (© 2018 American Heart Association, Inc.)

Subtype diagnosis of primary aldosteronism (PA) by adrenal vein sampling (AVS) is recommended as a mandatory step for indicating adrenal surgery. It is a technically demanding procedure, especially in the right adrenal vein. The aim of the study was to predict the subtype diagnosis in the absence of values from the right AVS. From the databases of nine centers (WAVES-J), 308 patients with PA who underwent successful AVS were studied. Based on the ipsilateral ratio (IR) (aldosterone/cortisol ratio of the left adrenal vein [A/C left AV ] / aldosterone/cortisol ratio of the inferior vena cava [A/C IVC ]), the patients were divided into two groups: the patients with IR ≥ 1.0 (n = 262) and those with IR < 1.0 (n = 46). In patients with IR > 1.0, the A/C left AV was significantly higher in patients with the left unilateral subtype than in patients with the bilateral subtype. Receiver operating characteristic (ROC) curve analysis revealed that an A/C left AV cutoff >68 showed 70.8% sensitivity and 93.5% specificity for the left unilateral subtype. On the other hand, in patients with IR < 1.0, the A/C left AV was significantly lower in patients with the right unilateral subtype. ROC analysis revealed that an A/C left AV cutoff <9 showed 86.7% sensitivity and 75.0% specificity for the right unilateral subtype. Hence, the combination of the IR and A/C ratio in the left adrenal vein is useful for predicting the subtype. The present results provide important information for patients with PA in whom AVS was unsuccessful in the right adrenal vein.

Context: Although adrenal vein sampling (AVS) is the standard method for subtype diagnosis in primary aldosteronism (PA), protocol details including the sampling position in the adrenal vein are not standardized., Objective: To establish the optimum sampling position in the left adrenal vein based on postoperative outcome in PA patients., Design and Setting: Retrospective study in nine referral centres., Participants: Of 496 consecutive PA patients who underwent AVS between 2006 and 2013, 217 with successful AVS under cosyntropin stimulation, and with concomitant data from two positions: proximal (common trunk) and distal (central vein) to the junction with the inferior phrenic vein, were included., Main Outcome Measures: Discordant rate of subtype diagnosis between common trunk and central vein, and postoperative outcomes in patients with discordant results., Results: Subtype diagnosis using common trunk and central vein was discordant in 10 (4·6%) of the 217 patients (κ = 0·87, P < 0·05). Of these 10 patients, eight with left unilateral subtype and two with bilateral subtype using common trunk data showed bilateral subtype and unilateral subtype, respectively, using central vein data. Five patients with left unilateral subtype and one with bilateral subtype by common trunk data underwent unilateral adrenalectomy. All six patients were cured of PA after adrenalectomy, resulting in false-negative rates of 17% (1/6) by common trunk data, and 83% (5/6) by central vein data., Conclusion: In view of its better potential diagnostic accuracy, technical ease, lower cost and lower risk of vein rupture, blood sampling from the common trunk of the left adrenal vein may be preferable as the standard method of AVS in patients with PA, although additional studies in a larger number of cases are required., (© 2015 John Wiley & Sons Ltd.)

Objectives: Adrenal vein sampling (AVS) is the standard criterion for the subtype diagnosis in primary aldosteronism (PA). Although lateralized index (LI) ≥4 after cosyntropin stimulation is the commonly recommended cut-off for unilateral aldosterone hypersecretion, many of the referral centres in the world use LI cut-off of <4 without sufficient evidence for its diagnostic accuracy., Aim: The aim of the study was to establish the diagnostic significance of contralateral (CL) aldosterone suppression for the subtype diagnosis in patients with LI <4 in AVS., Design and Patients: A retrospective multicentre study was conducted in Japan. Of 124 PA patients subjected to unilateral adrenalectomy after successful AVS with cosyntropin administration, 29 patients with LI < 4 were included in the study. The patients were divided into Group A with CL suppression (n = 16) and Group B (n = 13) without CL suppression. Three outcome indices were assessed after 6 months postoperatively: normalization/significant improvement of hypertension, normalization of the aldosterone to renin ratio (ARR) and normalization of hypokalaemia., Results: The normalization/significant improvement of hypertension was 81% in Group A and 54% in Group B (P = 0·2). The normalization of ARR was 100% in Group A and 46% in Group B (P = 0·004). Hypokalaemia was normalized in all patients of both groups. The overall cure rate of PA based on meeting all the three criteria was 81% in Group A and 31% in Group B (P = 0·01)., Conclusions: In patients with PA, where the LI is <4 on AVS, CL suppression of aldosterone is an accurate predictor of a unilateral source of aldosterone excess. CL suppression data should be interpreted in conjunction with computed tomographic adrenal imaging findings to guide surgical management., (© 2015 John Wiley & Sons Ltd.)

Background: Basal and bolus insulin therapy is required for strict blood control in diabetic patients, which could lead to prevention of vascular complications in diabetes. However, the optimal combination regimen is not well established., Methods: Fifty-nine diabetic patients (49 type 1 and 10 type 2; 52.9 ± 13.3 years old) whose blood glucose levels were uncontrolled (HbA1c  > 6.2%) by combination treatment of basal insulin glargine with multiple daily pre-meal injections of bolus short-acting insulin [aspart (n = 19), lispro (n = 37) and regular human insulin (n = 3)] for at least 8 weeks were enrolled in this study. We examined whether glycaemic control and vascular injury were improved by replacement of short-acting insulin with glulisine. Patient satisfaction was assessed with Diabetes Treatment Satisfaction Questionnaire., Results: Although bolus and basal insulin doses were almost unchanged before and after replacement therapy, switching to glulisine insulin for 24 weeks significantly decreased level of HbA1c , advanced glycation end products (AGEs), soluble receptor for AGEs (sRAGE), monocyte chemoattractant protein-1 (MCP-1) and urinary albumin excretion. In multiple stepwise regression analysis, change in MCP-1 values from baseline (ΔMCP-1) was a sole determinant of log urinary albumin excretion. ΔAGEs and ΔsRAGE were independently correlated with each other. The relationship between ΔMCP-1 and ΔsRAGE was marginally significant (p = 0.05). Replacement of short-acting insulin by glulisine significantly increased Diabetes Treatment Satisfaction Questionnaire scores., Conclusions: Our present study suggests that combination therapy of glargine with multiple daily pre-meal injections of glulisine might show superior efficacy in controlling blood glucose, preventing vascular damage and improving treatment satisfaction in diabetic patients., (Copyright © 2014 John Wiley & Sons, Ltd.)

Adaptation of the optokinetic response (OKR) is an eye movement enhanced by repeated motion of a surrounding visual field and represents a prototype of cerebellum-dependent motor learning. Purkinje cells and vestibular nuclei (VN) receive optokinetic and retinal slip signals via the mossy fiber-granule cell pathway and climbing-fiber projections, respectively. To explore the neural circuits and mechanisms responsible for OKR adaptation, we adopted the reversible neurotransmission-blocking (RNB) technique, in which granule-cell transmission to Purkinje cells was selectively and reversibly blocked by doxycycline-dependent expression of transmission-blocking tetanus toxin in granule cells. Blockade of granule-cell inputs abolished both short-term and long-term OKR adaptation induced by repeated OKR training, but normal levels of both responses were immediately evoked in the pretrained RNB mice by OKR retraining once granule-cell transmission had recovered. Importantly, eye movement elicited by electrical stimulation of the cerebellar focculus was elevated by long-term but not by short-term OKR training in adaptive OKR-negative RNB mice. Furthermore, when the flocculus of adaptive OKR-negative RNB mice was electrically excited in-phase with OKR stimulation, these mice exhibited long-term adaptive OKR. These results indicate that convergent information to the VN was critical for acquisition and storage of long-term OKR adaptation with conjunctive action of Purkinje cells for OKR expression. Interestingly, in contrast to conditioned eyeblink memory, the expression of once acquired adaptive long-term OKR was not abrogated by blockade of granule-cell transmission, suggesting that distinct forms of neural plasticity would operate in different forms of cerebellum-dependent motor learning.

Primary aldosteronism (PA), characterized by the autonomous hypersecretion of aldosterone, is the most common cause of secondary hypertension. Patients with PA have a higher risk of cardiovascular morbidity than essential hypertension. The two common subtypes of PA, aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA), should be differentiated, because the former is an indication for adrenalectomy, and the latter is treated by medication. 18-Hydroxycortisol and 18-oxocortisol, known as hybrid steroids, have been recognized as markers for the differentiation of aldosterone-producing adenoma and rare glucocorticoid remediable hyperaldosteronism from other subtypes of PA. Hybrid steroids have been measured using immunoassays such as enzyme-linked immunoassays; however, immunoassays for hybrid steroids are not widely used. Recently, liquid chromatography-tandem mass spectrometry (LC-MS/MS) for hybrid steroids was developed. The ability to measure hybrid steroids using LC-MS/MS will be useful for the differential diagnosis of subtypes of PA.

We demonstrated the formation of calcite thin films on positively and negatively charged surfaces of a hydroxyapatite (HAp) electret coexisting with polyacrylic acid (PAA) and self-generating surface electric fields due to HAp electrets with electrically aligned dipoles. The cooperation of PAA and the self-generating surface electric field due to the electrets favored the formation of calcite thin films and acted remarkably on the negatively charged surface. Calcite thin films, 4-10 microm thick, with a shell-like microstructure were produced on the negatively charged surfaces with a small amount of PAA. In contrast, under other reaction conditions, calcite thin films with a fan-like structure in the cross section formed on the polarized substrates, and their thickness ranged from 2 to 7 microm. The films were composed of hemispheric- or flat island-shaped aggregates that were made of the calcite crystals that elongated along the c-axis. The morphology of the PAA-Ca(2+) complex assembly, which adsorbed onto the polarized HAp substrates, was controlled by the balance of the spatial charge distribution in its structure and the properties of the self-generating surface electric field, which led to the different morphologies of the calcite thin films. We proposed that the formation mechanism of the films formed coexisting with PAA and the self-generating electric fields.

Classical conditioning of the eyeblink reflex is elicited by paired presentation of a conditioned stimulus and an unconditioned stimulus and represents a basic form of cerebellum-dependent motor learning. Purkinje cells and the deep nuclei receive convergent information of conditioned stimulus and unconditioned stimulus through the mossy fiber and climbing fiber projections, respectively. To explore the relative importance of these neural circuits and the underlying mechanism in associative eyeblink learning, we adopted a novel gene-manipulating technique, termed reversible neurotransmission blocking (RNB). In this technology, cerebellar granule cells specifically expressed neurotransmission-blocking tetanus toxin in a doxycycline (DOX)-dependent manner. Extracellular recording of Purkinje cells in awake RNB mice revealed that DOX treatment and withdrawal reversibly turned off and on simple spikes elicited by granule cell inputs, respectively, without interference with complex spikes evoked by climbing fiber inputs. Blockade of granule cell inputs to Purkinje cells abolished eyeblink conditioned responses (CRs) in a DOX-dependent manner. Importantly, when granule cell inputs recovered by removal of DOX, normal CRs were immediately produced in the DOX-treated, CR-negative RNB mice from the beginning of reconditioning. This learning process in RNB mice during DOX treatment was completely abolished by bilateral lesion of the interpositus nucleus before eyeblink conditioning. These results indicate that the convergent information at the interpositus nucleus is critical for acquisition and storage of learning in intimate association with the Purkinje cell circuit for expression of CRs in eyeblink conditioning.