Short-Term Visual Experience Leads to Potentiation of Spontaneous Activity in Mouse Superior Colliculus / 神经科学通报·英文版

Spontaneous activity in the brain maintains an internal structured pattern that reflects the external environment, which is essential for processing information and developing perception and cognition. An essential prerequisite of spontaneous activity for perception is the ability to reverberate external information, such as by potentiation. Yet its role in the processing of potentiation in mouse superior colliculus (SC) neurons is less studied. Here, we used electrophysiological recording, optogenetics, and drug infusion methods to investigate the mechanism of potentiation in SC neurons. We found that visual experience potentiated SC neurons several minutes later in different developmental stages, and the similarity between spontaneous and visually-evoked activity increased with age. Before eye-opening, activation of retinal ganglion cells that expressed ChR2 also induced the potentiation of spontaneous activity in the mouse SC. Potentiation was dependent on stimulus number and showed feature selectivity for direction and orientation. Optogenetic activation of parvalbumin neurons in the SC attenuated the potentiation induced by visual experience. Furthermore, potentiation in SC neurons was blocked by inhibiting the glutamate transporter GLT1. These results indicated that the potentiation induced by a visual stimulus might play a key role in shaping the internal representation of the environment, and serves as a carrier for short-term memory consolidation.

Safety evaluation of coenzyme Q10 on central nervous system / 药物评价研究

Objective To investigate the effect of high-dose coenzyme Q10 on the central nervous system in mice,and to provide experimental basis for clinical safety evaluation.Methods Mice were randomly divided into vehicle control group,perillartine control group,positive control group (chlorpromazine or diazepam) and coenzyme Q10 low,medium and high dose groups (1.5,3.0 and 6.0 g/kg,equivalent to 75,150,and 300 times of clinical dosage,respectively).The corresponding drugs were ig given to mice with the volume of 40 mL/kg.The general behavior of mice was observed directly,the motor coordination ability was observed by rotating stick method,and Anymaze animal behavior video analysis system was used to observe the spontaneous activity of mice and synergistic reaction with sub-threshold dose of pentobarbital sodium.Results There were no significant differences in the general behavioral activity,and the number of spontaneous activity times,mean resident time,and ratio of sleeping were found in all coenzyme Q10 groups,compared with the vehicle and perillartine control groups.Conclusion High dose of coenzyme Q10 has no significantly toxic effect on the central nervous system in mice,which could provide a reliable experimental basis for further medication study and clinical application of high-dose coenzyme Q 10.

Safety evaluation of coenzyme Q10 on central nervous system / 药物评价研究

Objective To investigate the effect of high-dose coenzyme Q10 on the central nervous system in mice,and to provide experimental basis for clinical safety evaluation.Methods Mice were randomly divided into vehicle control group,perillartine control group,positive control group (chlorpromazine or diazepam) and coenzyme Q10 low,medium and high dose groups (1.5,3.0 and 6.0 g/kg,equivalent to 75,150,and 300 times of clinical dosage,respectively).The corresponding drugs were ig given to mice with the volume of 40 mL/kg.The general behavior of mice was observed directly,the motor coordination ability was observed by rotating stick method,and Anymaze animal behavior video analysis system was used to observe the spontaneous activity of mice and synergistic reaction with sub-threshold dose of pentobarbital sodium.Results There were no significant differences in the general behavioral activity,and the number of spontaneous activity times,mean resident time,and ratio of sleeping were found in all coenzyme Q10 groups,compared with the vehicle and perillartine control groups.Conclusion High dose of coenzyme Q10 has no significantly toxic effect on the central nervous system in mice,which could provide a reliable experimental basis for further medication study and clinical application of high-dose coenzyme Q 10.

Resting-state functional MRI of regional spontaneous brain activity in classical trigeminal neuralgia patients / 中国医学影像技术

Objective To investigate the alterations of regional spontaneous activity in patients with classical trigeminal neuralgia (CTN) during resting state.Methods Twenty-seven patients with CTN (CTN group) and 27 healthy subjects (control group) were recruited and underwent a rest-state functional MRI.The regional homogeneity (ReHo) analysis was used to compare the differences of regional synchronization of spontaneous brain activity.And correlation tests were performed between ReHo values in the abnormal brain areas and clinical metrics (visual analogue scale and disease duration) of the disease.Results Compared with control group (P＜0.05,Gaussian random field correction),ReHo increased in bilateral primary somatosensory cortex (S1) and primary motor cortex (M1),right supplementary motor area (SMA),inferotemporal cortex and cerebellum,left thalamus,limbic lobe,parahippocampa gyrus,middle and superior temporal gyrus in CTN group;ReHo decreased in bilateral insula,prefrontal cortex and orbitofrontal cortex,right frontal medial cortex and superior temporal gyrus,left anterior cingulate area,supramarginal gyrus and cerebellum in CTN group.ReHo values in right frontal medial cortex was negatively correlated with the course of disease (r=-0.45,P=0.03).The ReHo values of left primary sensorimotor cortex were positively correlated with the visual analogue scale scores (r=0.46,P=0.02).Conclusion CTN patients has abnormal functional homogeneity of spontaneous brain activity in regions involved in the pain processing,which can help understanding mechanism of CTN.

Metabolic profile and spontaneous physical activity modulation under short-term food restriction in young rats

Abstract AIMS The aim of this study was to investigate the effects of short-term food restriction (6-weeks) on metabolic profile and spontaneous physical activity (SPA) of young male Wistar rats. METHODS Thirty rats had their baseline SPA measured at 21 days-old and were separated into two groups at 28 days-old: Control (CG) and 50% of food restriction (FR). The food restriction protocol lasted six weeks, being the SPA measured weekly by a gravimetric apparatus. At the end of the experiment, biochemical analyses were performed in serum and tissue samples with statistical significance set at 5%. RESULTS FR showed less SPA than CG, as occurred for body mass, water intake, adipose tissue and liver, heart and soleus glycogen, serum glucose, total protein, triglycerides and total cholesterol (P<0.05). CONCLUSION Data set demonstrates that low substrate stores signaled to decrease spontaneous physical activity to save energy.(AU)

Effect of agarwood produced by whole-tree agarwood-inducing technique on hypnotic and spontaneous activity inhibition of mice / 国际药学研究杂志

Objective To evaluate the sedative-hypnotic effect of agarwood different extracts produced by whole-tree agar?wood-inducing technique(Agar-Wit agarwood)to make scientific basis for the Agar-Wit agarwood exploration and usage in clinic. Method Collaborative pentobarbital sodium hypnosis experiment was employed to assess the index of fell asleep rate ,sleep latency time and sleep time. And locomotor activity assay was used to test the index of moved distance,travel time and average velocity. Then a functional comparison was made between Agar-Wit agarwood and commereial agarwood. Result The Agar-Wit agarwood ethanol ex?tract and essential oil could significantly increase sleep rate and prolong sleep time. At the same time ,essential oil could also decrease sleep latency time significantly. Additionally,both ethanol extract and oil significantly decreased the mice locomotor activity,includ?ing reduced total distance,movement,move time and average velocity. However,the water extract did not have significant effect. Conclusion The Agar-Wit agarwood ethanol extract and oil have significant effect on sedation in mice,whose function is similar to,or even better than that of the commerical agarwood.

Effect of agarwood produced by whole-tree agarwood-inducing technique on hypnotic and spontaneous activity inhibition of mice / 国际药学研究杂志

Objective to evaluate the sedative-hypnotic effect of agarwood different extracts produced by whole-tree agar- wood-inducing technique (Agar-Wit agarwood) to make scientific basis for the Agar-Wit agarwood exploration and usage in clinic. Method Collaborative pentobarbital sodium hypnosis experiment was employed to assess the index of fell asleep rate, sleep latency time and sleep time. And locomotor activity assay was used to test the index of moved distance, travel time and average velocity. Then a functional comparison was made between Agar-Wit agarwood and commereial agarwood. Result The Agar-Wit agarwood ethanol ex­tract and essential oil could significantly increase sleep rate and prolong sleep time. At the same time, essential oil could also decrease sleep latency time significantly. Additionally, both ethanol extract and oil significantly decreased the mice locomotor activity, includ­ing reduced total distance, movement, move time and average velocity. However, the water extract did not have significant effect. Conclusion The Agar-Wit agarwood ethanol extract and oil have significant effect on sedation in mice, whose function is similar to, or even better than that of the commerical agarwood.

Regional homogeneity changes in patients with trigeminal neuralgia / 中华神经医学杂志

Objective To explore the regional spontaneous activity changes in patients with trigeminal neuralgia (TN) using resting-state functional MRI.Methods Resting-state functional MRI datasets were acquired from 30 patients with TN,admitted to our hospital from July 2012 to December 2013,and 20 age,gender and education level matched healthy controls.The regional homogeneity (ReHo) method and independent-sample t-test were used to compare the brain activity differences between these two groups.Results Decreased ReHo values in the left temporal,left pam-hippocampal,as well as increased ReHo values in the bilateral thalamus and left parietal lobe were noted in TN patients as compared with those in the healthy controls.Conclusions The abnormal spontaneous activity exists in TN patients,and these abnormal regions are mainly associated with the perception and processing of pain.In addition,spontaneous activity alternation might promote the exploration of mechanism of TN.

Effect of eszopiclone on pentobarbital sodium-induced sleeping time in acute hypobaric hypoxia mice / 中华行为医学与脑科学杂志

Objective To assess the effects of eszopiclone (ESZ) on the pentobarbital sodium-induced sleeping time and spontaneous activity in mice exposed to acute hypobaric hypoxia.Methods 120 mice were randomly divided into 6 groups by using two factors 2×3 levels factorial design,in which two factors were interventions (ESZ and 0.9％ sodium chloride,2 levels) and altitudes (800 m,3500 m and 6000 m,3 levels).The pentobarbital sodium-induced sleeping test and the open field test were engaged to assess the effects of ESZ on sleeping time and spontaneous activity.Results (1) The drug and altitude had no interaction in the results of both the pentobarbital sodium-induced sleeping test and the open field test(P＞0.05).(2)The time of pentobarbital sodium-induced sleeping of mice in the groups of ESZ at each altitudes were (37.77± 18.22) min,(37.02± 13.67) min,(95.67±47.68)min and in the groups of NS were(17.78± 14.10) min,(15.09± 12.46) min,(39.54±28.24) min respectively,and the sleep time in ESZ groups were significantly longer than those in the groups of NS (P＜0.05).The time of pentobarbital sodium-induced sleeping were longer in group of 6000 m than those in the other two groups,both the ESZ and NS groups (P＜0.05).(3)No significant difference was found in the open field test between the ESZ and NS groups in the same altitude(P＞0.05) ; while the mice at the altitude of 6000 m in groups of ESZ and NS decreased compared with the groups at the altitude of 800 m after the relevant drugs intra-perineally for 6 h (P＜0.05).Conclusion ESZ may prolong pentobarbital sodium-induced sleeping time especially at the altitude of 6000 m and with no influence on the spontaneous activity in mice exposed to acute hypobaric hypoxia.High altitude at 6000 m may prolong the sleep time induced by pentobarbital sodium and reduce the spontaneous activities.

Study on Sedative and Hypnotic Effects of Different Eluents of Shuangxiatang / 世界科学技术-中医药现代化

This article was aimed to study the sedative and hypnotic effects of different eluents of Shuangxiatang (SXT). The effects of SXT water decoction, water eluent, 20%, 70% and 95% alcohol eluent on spontaneous ac-tivity and the sleeping induced by subthreshold dose of pentobarbital sodium were measured. The results showed that the SXT decoction, 20% and 95% alcohol eluent can significantly decrease the number of rearing in mice with the percentage of 78.5%, 78.3% and 62.5%, respectively. SXT water eluent and 70% alcohol eluent can significantly decrease the spontaneous activity of mice (P < 0.01), the number of rearing (P < 0.01) and grooming time (P < 0.05). SXT water decoction can significantly shorten sleep latency (P < 0.05), prolong sleep time (P <0.05), and increase rates of sleeping in mice. SXT water eluent can significantly shorten sleep latency in mice (P< 0.05), increase rates of sleeping in mice. SXT water decoction and water eluent have the sedative and hypnotic effects. And the effects are more than alcohol eluents.

Análise toxicológica da fase I do exsudato extraído do fruto de Mangifera indica L. / Análisis toxicológico de la fase I del exudado del fruto de Mangifera indica L. / Toxilogical analysis phase I of the exudates from Mangifera indica L. fruit

Introdução: as plantas representam ainda uma importante fonte de materia prima para a confecção de medicamentos. Mas, apesar do grande número de espécies vegetais no Brasil, apenas uma pequena parcela tem sido estudada adequadamente. A Mangifera indica, hoje integrante da flora brasileira, tem em suas diferentes partes, substâncias ativas importantes, embora não haja na literatura informações sobre os efeitos dos componentes existentes no exsudato do pedúnculo do fruto, principalmente das suas fases de separação espontânea. Objetivo: avaliação das respostas espontâneas em Rattus novergicus albinus, adultos, sob o efeito da fração hidrofílica do exsudato do pedúnculo do fruto de Mangifera indica. Métodos: a obtenção do exsudato do pedúnculo dos frutos de Mangifera indica de espécimes obtidos do Campus da Universidade Federal Rural de Pernambuco foi providenciada. Após um período de decantação de seis dias, espontaneamente, foram visualizadas quatro fases distintas. Da fase um, após os devidos processos de separação e pesagens, alíquotas de 0,5 mL foram administradas, intraperitonealmente, em cada animal, sendo a atividade espontânea observada por 100 min. Resultados: em relação ao grupo controle, foram observadas respostas comportamentais sugestivas, tais como tremores mandibulares, variações importantes nos ritmos de ventilação pulmonar, micção, cauda apoiada à superfície, catatonia, locomoção retrógrada, movimentos mandibulares, contração do focinho, inércia a estímulos para marcha, dificuldade de locomoção, hipnose, contração abdominal, piloereção na cauda e analgesia. Estas respostas apresentaram intervalos temporais de ocorrência característicos. Não ocorreram óbitos. Conclusões: as respostas observadas sugerem que importantes mecanismos fisiológicos sejam oportunamente acionados quando os animais estão sob os efeitos dos constituintes químicos da fase 1, hidrofílica, do exsudato de Mangifera indica; podendo, a partir de estudos posteriores, proporcionar a obtenção de drogas importantes para a medicina.

Introducción: las plantas representan aún una importante fuente de materia prima para la confección de medicamentos. Pero, a pesar del gran número de especies vegetales de Brasil, apenas una pequeña parte ha sido estudiada adecuadamente. Mangifera indica, integrante en la actualidad de la flora brasileña, tiene en sus diferentes partes sustancias activas importantes, sin embargo, no se encuentra en la literatura información sobre los efectos de los componentes existentes en el exudado del pedúnculo del fruto, principalmente en sus fases de separación espontánea. Objetivo: evaluar las respuestas espontáneas en Rattus novergicus albinus adultos, bajo el efecto de la fracción hidrofílica del exudado del pedúnculo del fruto de Mangifera indica. Métodos: se logró la obtención del exudado del pedúnculo de los frutos de Mangifera indica a partir de especímenes obtenidos del Campus de la Universidad Federal Rural de Pernambuco. Tras un período de decantación de 6 d, espontáneamente, se pudieron visualizar 4 fases diferentes. De la fase uno, tras los debidos procesos de separación de pesaje, se administraron alícuotas de 0,5 mL, intraperitonealmente, en cada animal y se observó la actividad espontánea durante 100 min. Resultados: comparado con el grupo de control, se observaron respuestas conductuales sugestivas, como temblores mandibulares, variaciones importantes en los ritmos de ventilación pulmonar, micción, cola apoyada en la superficie, catatonia, locomoción retrógrada, movimientos mandibulares, contracción del hocico, inercia a estímulos para marchar, dificultades en la locomoción, hipnosis, contracción abdominal, piloerección de la cola y analgesia. Estas respuestas presentaron intervalos temporales de ocurrencia característicos. No se produjeron muertes. Conclusiones: las respuestas observadas sugieren que importantes mecanismos fisiológicos son oportunamente accionados cuando los animales están bajo los efectos de los constituyentes químicos de la fase 1 del exudado hidrofílico de Mangifera indica. Sobre la base de estudios posteriores pudiera lograrse la obtención de drogas importantes para la medicina.

Introduction: the plants still represent an important source of raw material for making medicines. Despite the large number of plant species in Brazil, only a small portion has been adequately studied. Mangifera indica L, a member of the Brazilian flora, has important active substances in its various parts, although there is information in the literature on the effects of existing components in the exudate of the fruit peduncle, especially the spontaneous separation of phases. Objective: evaluation of spontaneous responses in Rattus novergicus albinus, adults under the influence of the hydrophilic fraction of the exudates from the stalk of the Mangifera indica fruit. Methods: the exudate obtained from the stalk of Mangifera indica fruits specimens obtained from the Campus UFRPE was provided. After a settling period of six days, four distinct phases were spontaneously seen. In phase one, after the separation and weighing processes, 0.5 mL aliquots were administered intraperitoneally in each animal, and the spontaneous activity was observed for 100 min. Results: compared with the control group, suggestive behavioral responses were observed such as mandibular tremors, important variations in pulmonary ventilation rates, urination, tail supported at the surface, catatonia, retrograde movement, jaw movements, contraction of the muzzle, inertia to gait stimulation, difficult walking, hypnosis, abdominal contraction, piloerection on the tail, and analgesia. These responses presented characteristic time intervals for occurrence. There were no deaths. Conclusions: the responses suggested that important physiological mechanisms are appropriately triggered when the animals are under the effects of the chemical constituents included in the first phase. Based on further studies, Mangifera indica L. hydrophilic exudate could allow obtaining important medical drugs.

Influence of scopolamine hydrobromide orally disintegrating tablets on neurological behaviors in mice / 第二军医大学学报

Objective To study the effects of scopolamine hydrobromide orally disintegrating tablets (DTs) based nanospheres-particles (NiMS) system on the neurological behaviors in mice, so as to provide evidence for clinical administration. Methods The 3 tests in this study were all divided as following: twenty male and 20 female mice were each randomly divided into 4 groups, with 5 mice in each group. Then a female and a male group were merged into one group, so there were 4 groups, each containing 10 mice. The four groups were subjected to the following treatments: control, high dose (24 mg/kg), moderate dose (15 mg/kg) and low dose DTs (6 mg/kg). To study the effects of DTs on the balance capacity, we selected 40 mice with the ability to climb the bar from 50 mice. (1) The spontaneous activities of mice were observed and recorded 20 min after intragastric administration of DTs in each group. (2) Pentobarbital sodium was intraperitoneally injected in mice 20 min after intragastric administration of DTs to observe the sleep of mice, so as to evaluate the synergistic effect between the two drugs. (3) Mice were put on the top of a stainless bar 20 min after intragastric administration of DTs and the time spent by the mice from top to the bottom of bar was recorded to evaluate the impact of the medication on mouse balance capacity. Results (1) DTs at each dose had no significant influence on the spontaneous activity of mice compared with the controls (P>0. 05). (2) The sleep time of mice increased with the dose of DTs, and there were significant difference between control group with high dose and moderate dose groups (P<0. 05). (3) DTs shortened the time spent by mice from top to the bottom of the bar compared with the control group, with significant differences found in female mice taking three doses of DTs (P< 0. 01) and in male mice taking high and moderate dose of DT (P<0. 01, P < 0. 05). Conclusion Intragastric administration of DTs has no influence on spontaneous activity of mice, and its synergistic effect with pentobarbital sodium increases with dose. DTs can also decrease the balancing capacity of mice.

Effects of abstinence on locomotor activity and contextual fear conditioning in morphine-dependent mice / 第二军医大学学报

Objective: To study the impact of different abstinence periods on locomotor activity and contextual fear conditioning in morphine-dependent mice. Methods: Morphine hydrochloride was administrated (sc) to mice at a gradually increasing dose for 7 d to establish morphine-dependent model. After the last injection, animals were divided into MW1 d (Morphine Withdrawal for 1 d), MW7 d, MW21 d, SW1 d (Saline Withdrawal for 1 d), SW7 d and SW21 d groups randomly; the spontaneous activities of mice, including the numbers of crossing and rearing, grooming times, the number of center entries and time spent in center area, and the time spent in peripheral area, were observed in the open field box after different periods of abstinence. After the observation, the mice were trained using eight unconditioned stimulus (0.5 s; 0.5 mA foot shock) and contextual fear conditioning was tested 24 h later. Results: The times of crossing and center entries decreased in MW1 d and MW7 d mice (W1 d: P<0.001, P<0.001; W7 d: P<0.001, P<0.05); the time of rearing in MW1 d group was also decreased significantly (P<0.001); mice in MW1 d group had more grooming behaviors (P<0.05). The periods spent in the center and peripheral areas were not significantly different between all the 3 morphine-dependent groups and their corresponding saline withdrawal groups. In addition, a history of morphine injection selectively impaired the contextual fear conditioning in mice of MW1 d group (P <0.05). Conclusion: During the early period of morphine abstinence, mice have a decreased spontaneous activity and an impaired contextual fear conditioning.

The Development of Abnormal Spontaneous Activities in the Experimental Radiculopathy in the Rat

OBJECTIVE: Through a animal study using rats, we investigated whether abnormal spontaneous activities (ASAs) could be observed in the radiculopathies of biochemical and mechanical model. METHOD: A total of 30 Sprague-Dawley male rats were randomly assigned into sham, nucleus pulposus (NP) and ligation groups. In the sham group, the right L4 and L5 nerve roots were exposed by laminectomies. In the NP group, nucleus pulposus was transplanted onto nerve roots from tail. In the ligation group, exposed nerve roots were ligated by silk ligatures. All rats were evaluated by mechanical allodynia, motor paresis, and the needle electromyography (EMG) examination. RESULTS: Mechanical allodynia was observed on the 4th and 7th postoperative days in NP and ligation groups. Motor paresis was observed only in the ligation group. The needle EMG showed ASAs on the 4th postoperative day, but decreased in incidence and amount on the 7th postoperative day in the NP and ligation groups. CONCLUSION: The ASAs can be observed by the biochemical action of nucleus pulposus as well as the mechanical compression. The results of this study may help explain the discrepancy between radiologic and electrodiagnostic findings.

Electrophysiological and morphological properties of the ventral neurons in medial geniculate body in rats / 第三军医大学学报

Objective To investigate the electrophysiological and morphological properties of the single ventral neuron in the medial geniculate body (MGBv) in rats. Methods The basic electrophysiological properties and action potentials at different levels of membrane potentials were recorded by whole cell patch clamp technique. Morphological properties of ventral neurons in the medial geniculate body were studied by biocytin staining. Results Nissl and biocytin stainings indicated that MGBv neurons were composed of oval shaped cell bodies, and the dendritic branches were tufted. In current clamp recordings, the resting membrane potential was (-54.92?10.85) mV, the input resistance (945.67?507.80) M?, the membrane capacitance (5.37?1.98) pF, and the time constant (2 109 87 ?2 496 01) ?s. Action potentials under different current inputs were various. Spontaneous discharge could be recorded by voltage clamp and current clamp. Conclusion MGBv dendritic trees are fairly dense with bushy tufted neurons and variety of action potentials under different current inputs in ventral neurons of the medial geniculate body. Spontaneous activities recorded by current clamp are similar to the action potential, which may be the spontaneous action potential due to the exceeding of membrane potential over liminal value.

Relation between Symptom Duration and Abnormal Spontaneous Activity in S1 Radiculopathy

OBJECTIVE: It is a widely accepted belief that paraspinal muscles tend to show spontaneous activity on needle electromyography early on in a radiculopathy and distal muscles become abnormal later on. But most studies have shown the limitations of using symptom duration when interpreting electrodiagnostic findings in radiculopathy. The purpose of this study was to determine the relationship between symptom duration and abnormal spontaneous activity in S1 radiculopathy confined to abnormal H-reflex. METHOD: A retrospective study that collected the informations on symptom duration and spontaneous activity in paraspinal muscle and gastrocnemius for 112 patients with S1 radiculopathy diagnosed by unilateral H-reflex abnormality was undertaken. RESULTS: Abnormal spontaneous activity in paraspinal muscle had shown a significant negative correlation with symptom duration, that is a tendency to decrease its expression over symptom duration. On the contrary abnormal spontaneous activity in gastrocnemius muscle was rare at first a few weeks and became to show after 7 weeks. Patients with symptom duration over 1 year had higher incidence of having no abnormal spontaneous activities both in paraspinal and gastrocnemius muscle. CONCLUSION: These results suggested that symptom duration had a potential role in the diagnosis of S1 radiculopathy when H-reflex were abnormal unilaterally.

Change of Abnormal Spontaneous Activities According to Time Course in Hemiplegic Upper Limb

OBJECTIVE: To evaluate the change of abnormal spontaneous activities according to the clinical and radiologic findings, and to the time course after onset in hemiplegic upper limb. METHOD: We scored abnormal spontaneous activities of hemiplegic upper limb muscles (infraspinatus, deltoid, extensor carpi radialis, abductor pollicis brevis, abductor digiti minimi) in 100 hemiplegic patients without peripheral neuropathy. The abnormal spontaneous activities were evaluated according to their radiologic findings and to Brunnstrom stage and the presence of reflex sympathetic dystrophy (RSD), and the time course after the onset (A cross-sectional study). In addition we repeatedly examined 40 hemiplegic patients until 12 weeks after the onset to define the pattern of change (A prospective study). RESULTS: There was no significant difference in the score of abnormal spontaneous activities according to the radiologic findings. The score of abnormal spontaneous activities decreased while Brunnstrom stage progressed. In both the cross-sectional and prospective studies, we found that the abnormal spontaneous activities decreased according to the time course after the onset in the limb without RSD, but sustained in the limb with RSD. CONCLUSION: Abnormal spontaneous activities decreased according to the progression of Brunnstrom stages. The hemiplegic patients with RSD showed more profuse and sustained abnormal spontaneous activities at needle EMG study of hemiplegic upper limb than the patients without RSD.

Abnormal Spontaneous Activities According to Type of Herniated Lumbar Disc and Anteroposterior Diameter of Dural Sac in MRI

OBJECTIVE: To assess the abnormal spontaneous activities in needle electromyography (EMG) according to the type of herniated lumbar disc and anteroposterior the diameter of dural sac in magnetic resonance imaging (MRI). METHOD: We performed the MRI on 120 patients with low back pain (LBP) and measured the midline anteroposterior diameter of dural sac in a MRI axial view. Fifty patients with a disc protrusion or extrusion in MRI were reviewed for the clinical findings on physical examination and assessed for the abnormal spontaneous activities (ASA) in needle EMG. RESULTS: Seventy cases with a normal finding in MRI did not have differences in a dural sac diameter regardless their age or sex. Fifty cases with a protrusion or extrusion in MRI showed that the dural sac size decreased more in an extrusion than in a protrusion, and more in a paracentral type than in a central type. The incidence of ASA in a needle EMG increased more in an extrusion than in a protrusion, and more in a paracentral type than in a central type. The incidence also increased according to the decrement of a dural sac diameter. The incidence of ASA were 100% in a group with both motor and sensory signs, 94% in a group with a motor sign, 86% in a group with a sensory sign, 26% in a group without motor or sensory sign. CONCLUSION: We concluded that the abnormalities in needle EMG must be correlated with the direction of herniated lumbar disc and anteroposterior diameter of the dural sac in MRI as well as clinical findings.

Spontaneous electrical activity in cerebellar Purkinje neurons of postnatal rats

Although cerebellar Purkinje cells display spontaneous electrical activity in vivo and in slice experiments, the mechanism of the spontaneous activity generation has not been clearly understood. The aim of this study was to investigate whether cerebellar Purkinje cells of postnatal rats generate spontaneous electrical activity without synaptic inputs. Dissociated cerebellar Purkinje cells were used for reducing synaptic inputs in the present study. Cerebellar Purkinje cells with dendrites were dissociated from postnatal rats using enzymatic treatment followed by mechanical trituration. Spontaneous electrical activities were recorded from dissociated cells without any stimulus using whole-cell patch clamp configuration. Two types, spontaneously firing or quiescent, of dissociated Purkinje cells were observed in postnatal rats. Both types of cells were identified as Purkinje cells using immunocytochemical staining technique with anti-calbindin after recording. Spontaneously active cells displayed two patterns of firing, repetitive and burst firings. Two thirds of dissociated Purkinje cells displayed repetitive firing and the rest of them did burst firing under same recording condition. Repetitive firing activities were maintained even after further isolation using either physical or pharmacological techniques. Neither high magnesium solution nor excitatory synaptic blockers, AP-5 and DNQX, block the spontaneous activity. These results demonstrate that spontaneous electrical activity of isolated cerebellar Purkinje cells in postnatal rats is generated by intrinsic membrane properties rather than synaptic inputs.