鲤鱼机器人无线遥控系统设计与应用

为解决有线控制时导线对水生动物机器人缠绕和运动束缚问题,设计一种鲤鱼机器人脑电刺激无线遥控系统。其中,系统硬件包括无线通信模块、电刺激信号生成模块、电源模块,系统软件包括串口通信设置、运动模式选择。将脑电极植入后在颅腔表面进行防水封固,将无线电刺激器放入防水包内搭载于鲤鱼机器人上,利用上位机远程控制无线电刺激器,令电刺激器发射信号通过电极刺激脑运动区,控制鲤鱼机器人运动。将鲤鱼机器人(n=10)置于水迷宫进行水下实验,结果显示该系统可以控制鲤鱼机器人的前进、左转向和右转向运动,成功率分别为60%、70%、80%,表明所设计系统及应用方法对鲤鱼机器人水下无线控制均是有效且可行的。     

海马内注射Aβ1-42寡聚体影响大鼠焦虑、抑郁行为及突触可塑性

目的:探讨淀粉样β蛋白(Aβ)对大鼠焦虑和抑郁行为的影响及其可能的突触机制。方法:将SD大鼠随机分为对照组(n=10)和Aβ1-42注射组(n=10)。通过联合采用高架十字迷宫、强迫游泳及电生理实验技术,以动物在迷宫开臂和闭臂中停留时间百分比、在强迫游泳中的不动时间以及在体海马场兴奋性突触后电位(fEPSP)的幅度作为主要观察指标,系统研究了海马内注射Aβ1-42寡聚体对大鼠焦虑、抑郁行为及海马突触可塑性的影响。结果:(1)Aβ1-42组大鼠在高架十字迷宫开臂中所停留的时间百分比明显大于正常组(P0.01),在闭臂中停留的时间百分比则明显小于对照组(P0.01);(2)Aβ1-42组大鼠在强迫游泳测试中"不动"时间较对照组明显增加(P0.01),"游泳"时间则明显减少(P0.05);(3)高频刺激(HFS)后Aβ1-42组大鼠的海马LTP受到明显压抑,HFS后即刻以及HFS后30 min和60 min时fEPSP平均幅度均明显下降(P0.05或P0.01)。结论:海马内注射Aβ可导致大鼠行为脱抑制、引起抑郁样行为并伤害突触可塑性,提示海马LTP的异常不仅影响学习记忆功能,可能也与焦虑和抑郁等精神行为异常的发生有关。     

一种无线闭环迷走神经刺激器及系统

为了治疗药物难治性癫痫,提出一种无线闭环迷走神经刺激器及系统,包括头戴式头皮脑电记录器、迷走神经刺激器、电磁耦合能量发射器和控制应用App,设计一种可以分离局部场电位和动作电位的生物信号前置放大器,一种刺激脉冲参数可调的迷走神经刺激器,一种电磁耦合能量发射器以及一个控制应用App。使用海岸线参数检测算法判定癫痫脑电信号的产生。测试结果表明,生物信号前置放大器对局部场电位和动作电位的放大增益分别为40和60 dB。迷走神经刺激器接收到来自控制应用App的刺激参数后,可以产生对应参数的双极性刺激脉冲。当发射器发射功率为30 dBm,发射线圈和接收线圈距离2 cm时,电磁耦合能量传输效率最大为15.4%。海岸线参数算法的正检率为88%。     

肠道生物机器人中驱动装置的刺激控制系统研究

针对目前肠道诊疗设备的驱动问题,引入一种全新的肠道诊疗没备一肠道生物机器人.利用生物体作为驱动装置,携带肠道诊疗装置进入肠道内,通过体外的控制中心遥控生物体的运动行为,实现诊疗装置在肠道内主动前进、后退和定点泊位.选取黄鳝作为肠道生物机器人的生物体,并在了解其运动控制机理的基础上,设计出刺激控制系统.该系统由刺激电极和刺激器两部分组成,其刺激电极为表面式刺激电极和植入式刺激电极;其刺激器由LabVIEW软件和数据采集卡构成.采用该系统进行体外刺激控制实验,初步获得控制黄鳝前进的方法,证实该系统的可行性.     

大鼠空间变换学习记忆模式

大鼠空间变换学习记忆模式锁志明，张世仪（中国医学科学院基础医学研究所生理室北京１００００５）目前研究海马、前额叶皮层等脑区在学习记忆中的作用，常采用以大鼠为对象的空间认知能力测定。例如Ｍｏｒｒｉｓ水迷宫、八臂迷宫的学习训练等。但设备及训练程序比较复杂...     

基于阵列电极的生物电刺激器研制

目的:设计制作一种用于阵列电极的便携式生物电刺激器。方法:下位机采用STM32L432KC作为硬件核心,设计小型DC-DC升压模块和光电隔离式双极性压控恒流源,通过串并转换芯片和光耦合双向可控硅选通电极输出电流;上位机采用Eclipse开发了在嵌入式Android系统下的人机交互软件,可以通过蓝牙模块以无线的方式灵活调节刺激电流幅值、脉宽、频率和电极选择方案。结果:刺激器能够选择最佳的刺激位点和刺激强度,为生物电刺激的临床应用和科学研究提供便利。结论:该仪器体积小、稳定性好、功耗低、操作方便,具有临床研究与推广价值。     

基于无线充电技术的胃肠电刺激系统

目的设计一种新型的植入式胃肠道刺激系统,不仅具有刺激功能,还具有肠电和压力检测功能,可用于检测胃肠道刺激的效果,同时增加无线能量供给,以实现刺激器的长期植入。方法系统由体内刺激模块、体外控制模块及无线能量传输模块组成。体外控制模块通过无线射频将控制信号传输到体内刺激模块,体内刺激模块的能量由体外能量发射装置通过电磁耦合进行供给。通过生物反馈控制检测不同刺激参数对胃肠道收缩活动的作用效果,实时调整刺激参数,输出需要的刺激脉冲。以模拟心电信号模拟肠电信号,进行了相关的体外实验。结果在体外实验中,系统可有效检测到2—20次／min的模拟心电信号,并实现实时刺激参数修改输出不同的刺激脉冲。该系统实现了电流检测功能,监测作用部分的胃肠电阻。经皮无线能量在两级线圈轴向距离为22mm时的接收充电稳定功率最大为0．93W,体内锂离子的充电电流为180～240mA。结论系统可检测到最大变化范围的模拟肠电信号。验证电流的作用效应为后续的恒流刺激模式提供参考。该系统的无线充电功能可满足植入式刺激器长期植入的能量需求。     

用于外周神经的干涉电流刺激器设计

设计了一种用于外周神经电刺激的干涉电流刺激器。该刺激器为两路电流输出,可以产生4种波形,每种波形的频率、幅度等参数可在上位机进行设置,频率分辨率为0.2 Hz,幅度分辨率为0.01 mA,时间分辨率为0.1 μs。该刺激器的特点在于可在刺激强度一定的条件下连续改变电流比,或在电流比一定的情况下连续改变刺激强度。上位机采用LabVIEW开发,下位机采用FPGA对3片DAC进行控制,DAC产生的波形信号经过隔离恒流源电路后施加到负载。经过测试,刺激器能够准确产生4种波形,电流偏差在2.6%以内,恒流效果良好。该刺激器体积小,操作简单,产生波形稳定,可以用于无损选择电刺激研究。     

电子耳蜗在医学中的应用

一、电刺激的种类 电刺激可分为三类:①功能性电刺激:指借电刺激恢复人体的某些收缩功能,如心脏起搏器,步态矫正器,瘫痪肢体刺激器等。1997年美国FDA批准了一种叫“自由臂”的手臂刺激器,将刺激电极植入瘫痪的手臂中,利用异侧肩部传感器控制臂和手指运动。又如美国研制一种“VOCARE”刺激器,将电极植入在骶骨下的神经节,可使脊柱损伤后大、小便失禁患者     

围绕两轴进行复杂的旋转刺激后大鼠全脑内Fos的表达(英文)

为了探讨旋转刺激与运动病发生的关系,本研究利用一种复杂的围绕两轴旋转的加速度刺激器刺激大鼠后,观察大鼠全脑内Fos蛋白的表达情况。动物被随机地分成四组,即正常对照组、两轴旋转刺激组、双侧迷路毁损组以及双侧迷路毁损后接受旋转刺激组。采用免疫组织化学染色方法观察全脑不同核团内Fos蛋白的表达情况。结果显示:(1)正常对照组和双侧迷路毁损组大鼠的脑内均未检测到Fos样免疫阳性产物;(2)两轴旋转刺激组的大鼠在给予复杂的围绕两轴旋转的加速度刺激后,在大鼠脑和脑干的多个核团内均可检测到Fos样免疫阳性神经元,其阳性产物主要表达于细胞核。其中在脑干内的前庭复合体的不同亚核(包括前庭内侧核、前庭上核和前庭下核),孤束核、蓝斑核、臂旁内侧核、臂旁外侧核,间脑的室旁核以及边缘系统的杏仁核等内均可观察到密集分布的Fos样免疫阳性神经元;(3)双侧迷路毁损组大鼠在接受复杂的围绕两轴旋转刺激后,在上述相应核团内均难以检测到Fos蛋白的表达。以上研究结果提示两轴旋转刺激可以有效地激活前庭神经元,而大鼠在接受前庭刺激后,脑和脑干的许多核团内大量的神经元可能通过与前庭核复合体发生直接或间接的纤维联系也被激活,这些被激活的神经元可能与运动病发生的复杂机制有关。     

MK-801 Impairs Reconsolidation of a “New” Memory and Affects the “Old” Memory in Operant Feeding-Related Behavior in an Eight-Arm Radial Maze in Rats

Neuroscience and Behavioral Physiology - Spatial memory deteriorated significantly in feeding-related operant behavior in an eight-arm radial maze in rats as a result of reactivation using a single...     

Differential behavioral responsiveness to ipsilateral and contralateral visual stimuli produced by unilateral rewarding hypothalamic stimulation in the rat

Rats were trained to respond to a visual cue signalling availability of brain reward on the left or the right side of a small chamber. Most of the rats began to respond more accurately to the visual cue presented on the side contralateral to brain stimulation than to the ipsilateral cue as the training progressed. The facilitation of the rat's response to the contralaterally presented visual cue was more evident when tested with visual cues presented simultaneously in both ipsilateral and contralateral sides. However, when tested with visual cues removed from both sides, this tendency became unclear. Additionally, monocular training gave evidence of identifying the visual cue ipsilateral to the open eye, irrespective of the electrode side. The results are interpreted as signifying that the ipsilateral hemisphere is activated by the brain stimulus and leads to improved discrimination of the contralateral visual cue because the visual system in the rat is crossed.     

Lesions of basolateral and central amygdala differentiate conditioned cue preference learning with and without unreinforced preexposure

In the separated arms conditioned cue preference (CCP) task rats are trained by confining them in one arm of an eight-arm radial maze with food and in another arm on the opposite side of the maze with no food on alternate days. After two such trials, rats prefer the food-paired arm when allowed to move freely between the two arms, neither of which contains food. However, if the rats are preexposed to the maze by exploring it without food before training, no preference is observed and at least 4 training trials are required to produce a CCP, suggesting that unreinforced preexposure to the maze latently inhibits acquisition. If this interpretation is correct, preexposure should reduce the size of the preference acquired with both 2 and 4 training trials. In Experiment 1, this prediction was replicated for 2 training trials; however, with 4 training trials, eliminating preexposure also eliminated the CCP. A previous finding that basolateral amygdala lesions impair the CCP with preexposure and 4 training trials was replicated in Experiment 2, but similar lesions had no effect on the CCP in non-preexposed rats given 2 training trials. In contrast, lesions of the central nucleus impaired the 2 training trial CCP but had no effect on the 4 training trial CCP. This double dissociation suggests that the BLA-mediated 4 training trial CCP may be due to learning about the reward features of the maze space, while the central-nucleus-mediated 2 training trial CCP may be due to a conditioned approach response.     

A dissociation of dorso-lateral striatum and amygdala function on the same stimulus-response habit task

This experiment tested the idea that the amygdala-based learning and memory system covertly acquires a stimulus-reward (stimulus-outcome) association during acquisition of a stimulus-response (S-R) habit task developed for the eight-arm radial maze. Groups of rats were given dorso-lateral striatal or amygdala lesions and then trained on the S-R habit task on the eight-arm radial maze. Rats with neurotoxic damage to the dorso-lateral striatum were severely impaired on the acquisition of the S-R habit task but showed a conditioned-cue preference for the stimulus reinforced during S-R habit training. Rats with neurotoxic damage to the amygdala were able to acquire the S-R habit task but did not show a conditioned-cue preference for the stimulus reinforced during S-R habit training. This pattern of results represents a dissociation of learning and memory functions of the dorsal striatum and amygdala on the same task.     

Anterograde and retrograde influence of vestibular stimulation on spatial working memory

Rats were trained in an eight-arm radial maze to explore the apparatus in search of a food reward. After completion of the training phase, some animals were submitted to a hemicerebellectomy (HCbed group), while others were used as a control group. To study the effects of vestibular stimulation on the recall of ongoing working memory information, both groups were exposed to radial maze sessions: in the first session (no-rotation), animals were confined for 30 s to the fourth arm visited without being further manipulated; in the second session (rotation), the animals were again confined for 30 s to the fourth arm visited, while the apparatus was rotated five times around its vertical axis. The effects of these manipulations on successive visits to complete the task were assessed, as well as the solving time and kinds of errors made. Errors were significantly more frequent in the control animals during the rotation session; HCbed animals were unaffected by confinement alone or by vestibular stimulation, but showed a decreased search speed. It was concluded that vestibular input is required for an adequate functioning of the working memory system devoted to the formation and consolidation of spatial mnesic traces and that the amnesic effect due to vestibular stimulation is both anterograde and retrograde in nature.     

Fos expression in the rostral thalamic nuclei and associated cortical regions in response to different spatial memory tests

Using the quantification of the Fos protein as an indicator of neuronal activation, we studied the involvement of the rostral thalamic nuclei and associated structures in different spatial memory tasks in two experiments. In both experiments, tasks were matched for sensorimotor factors but differed in their spatial and mnemonic demands. In Experiment 1, matched groups of rats either ran in a standard eight-arm radial maze or ran up and down just one arm of the maze while the number of runs and rewards were matched across pairs of rats. In Experiment 2, both groups were trained on the eight-arm radial maze but in different rooms. On the test day, one group was moved so that both groups now performed the same radial-maze task in the same room but for one group the extramaze cues were novel. There were significant increases in Fos in all three of the anterior thalamic nuclei (anterodorsal, anteroventral and anteromedial) as well as the adjacent nucleus reuniens and rostral reticular thalamic nucleus, in both the eight-arm versus one-arm condition (Experiment 1) and the novel room versus familiar room condition (Experiment 2). There were no significant differences in the mediodorsal thalamic nucleus in either experiment. The more spatially demanding task in each experiment also resulted in increased Fos expression in the subicular complex (postsubiculum, presubiculum and parasubiculum), as well as in the prelimbic cortex. Performing the standard radial-arm maze task also produced significant Fos increases in both rostral and caudal levels of the retrosplenial cortex when compared to rats running up and down a single arm in the same maze (Experiment 1); performing the task in a novel room did not, however, result in any further Fos increases in this region (Experiment 2). The specificity of the changes in levels of Fos was shown by a lack of any consistent difference in levels in six control sites.The present results reveal a group of anatomically related structures that work together in the intact rat brain during tasks that tax allocentric spatial working memory.     

Presynaptic inhibition compared with homosynaptic depression as an explanation for soleus H-reflex depression in humans

 Head direction (HD) and place cells were recorded in rats that had previously exhibited significant acquisition deficits on a radial arm maze task following disorientation treatment. In this study we determined whether this behavioral impairment was associated with a lack of landmark stimulus control over the preferred orientations of HD and place cells. Neurons were recorded as animals retrieved food pellets in a cylindrical apparatus containing a single cue card. Some of these HD cells were also recorded while animals explored an eight-arm radial maze in a similar cue-controlled environment. The stimulus control of the landmarks in each environment was assessed by rotating the landmark and examining the subsequent preferred orientations of HD and place cells. Animals underwent disorientation treatment before and after each recording session. Despite this disorientation, rotation of the cue card in the cylindrical apparatus resulted in a corresponding shift in the preferred orientations of HD and place cells in 13 of 15 and 7 of 7 recording sessions, respectively. On the radial arm maze, rotation of the landmark cue was associated with a corresponding shift in the HD cell’s preferred orientation in 7 of 9 sessions. These results suggest that a visual landmark’s stimulus control may not require a learned association between that landmark and an animal’s stable experience in an environment. Furthermore, instability in the HD cell system is unlikely to account for the impaired performance of the disoriented animals in the radial arm maze. Rather, these impairments may be due to the animal’s inability to utilize stable representations of the environment provided by HD and place cells. Received: 18 November 1996 / Accepted: 24 January 1997     

Effects of ibotenic acid lesions to rat's hippocampus CA1 on place and cue learning in Morris water maze

It is known that the multiple injections of ibotenic acid to the hippocampal CA1 (Cornu Ammonis 1) field of a rat cause cell loss and spatial learning impairment in the place task of Morris water maze. However, no study seems to have been conducted concerning the cue task of the maze. This study examined (1) whether cell loss in the CA1 field produced learning deficits in both the place and cue tasks; (2) whether training could remedy the deficit in spatial learning; and (3) whether the order of place training and cue training could change the performance outcome. Thirty-seven rats of Wistar strain were divided into Place-Cue (PC) group that received place training first and then cue training, and Cue-Place (CP) group that received training in the reverse order. Half rats in each group were damaged in the CA1 field by ibotenic acid injections. Results indicated that damage to CA1 pyramidal cells led to performance deficits only in the place task throughout training, regardless of the sequence of training. The results also indicated that training in the prior task affected learning in the succeeding task, only at the beginning of training, and the effect is transient.     

Effects of ovarian hormones and environment on radial maze and water maze performance of female rats

The effects of gonadal hormones and environment on performance in an eight-arm radial maze and in the Morris water maze were determined in female rats. Long-Evans female rats were ovariectomized or sham ovariectomized at 35 days of age, and housed in complex environments or in isolation for the duration of the study. One month following surgeries, spatial working memory performance in the radial maze was assessed. Exposure to complex environmental conditions independently enhanced performance, as indicated by increased arm choice accuracy during 20 days of maze training. Additionally, gonadally intact females significantly outperformed ovariectomized females before cyclicity was disrupted by food deprivation. Following radial maze training, spatial reference memory performance was assessed in the same females utilizing the Morris water maze. Gonadally intact females housed in isolation performed significantly more poorly during 16 days of place training trials and displayed significantly shorter times in the platform quadrants and fewer target crossings during probe trials than gonadally intact and ovariectomized females housed in complex environments and ovariectomized rats housed in isolation. Consequently, acquisition and retention of the water maze was impaired by the presence of ovaries, and this impairment was counteracted by exposure to complex environments. Performance did not differ between groups on cued trials, indicating that sensorimotor and motivational functions did not differ between groups. Results of these experiments indicate that endogenous gonadal hormones can differentially affect performance on tasks of spatial working and spatial reference memory, and that environmental conditions can interact with gonadal hormones to affect behavior.     

Environmental enrichment reduces impulsivity during appetitive conditioning

Although environmental enrichment is presumed to enhance learning, appetitive behavior may also be altered by this experience: anticipatory responding for sucrose is reduced in environmentally enriched (EE) rats [van der Harst, J.E., Baars, A.M. and Spruijt, B.M. Standard housed rats are more sensitive to rewards than enriched housed rats as reflected by their anticipatory behaviour. Behav Brain Res 2003;142:151-156]. To assess the impact of differential environmental experience on learning and appetitive behavior, we trained 17 EE and socially isolated (SI) rats in a three-phase, operant-shaping procedure for sucrose reinforcement. In phase one, a feeder cue was paired with sucrose availability. In phase two, a nose poke to either one of two lit holes on the opposing wall activated the feeder cue. In phase three, the feeder cue was elicited by a poke to a single lit hole. While acquisition rates in phase one and phase two were similar, EE animals reached phase-three criteria [completion of 100 trials in 45 min and 15 or fewer bad pokes] faster than SI animals. These two groups showed similar session completion rates, reinforced and non-reinforced licking responses, and overall behavioral activity during phase three acquisition; however, SI rats performed more bad pokes (responses to the non-lit hole after nose-poke cue onset) and intertrial interval (ITI) pokes during this training period. Because all ITI (and presumably many bad) pokes were initiated before onset of nose-poke cue, this difference indicates greater anticipatory responding in SI animals. This experience-dependent alteration in appetitive behavior may explain, in part, the tendency of SI rats to show attenuated learning rates in appetitive contexts in which complex contingencies exist.