树鼩血压和心率的无创测定

目的建立健康树鼩的心率、血压正常值参考范围,并探讨不同来源、不同性别、不同年龄树鼩心率、血压的差异。方法随机挑选实验树鼩180只,按来源分为野生成年组、F1代自繁成年组和青幼年组三个组,每组雌雄各半,共60只。采用智能无创血压计（鼠仪）逐只测定HR（心率）、SBP（收缩压）、DBP（舒张压）和MBP（平均动脉压）。结果野生成年树鼩、自繁成年树鼩和青幼年树鼩心率分别为394.33±37.74 BPM、351.61±72.76 BPM和378.19±69.04 BPM,野生和自繁成年树鼩组差异有显著性（P〈0.05）。自繁成年树鼩收缩压、舒张压和平均动脉压均明显低于青幼年树鼩,差异有极显著性（P〈0.01）。野生成年树鼩和自繁成年树鼩相比,收缩压、舒张压和平均动脉压差异均无显著性（P〉0.05）。结论大鼠无创血压计适合于树鼩的血压、心率的测量。通过测定,获得了野生成年树鼩、F1代自繁成年树鼩和青幼年树鼩的心率和血压参考值范围,丰富了树鼩基础生理数据,可为相关研究提供科学参考。     

神经鞘磷脂合成酶2缺乏对小鼠学习记忆能力的影响

目的：探讨神经鞘磷脂合成酶2缺乏对小鼠学习记忆能力的影响,方法：实验采用雄性的野生型小鼠（WT）和神经鞘磷脂酶合成酶2缺乏小鼠（KO）,每组10只,采用Morris水迷宫实验进行7 d的定位航行试验检测,之后进行空间探索试验,以检测小鼠的学习记忆能力。结果：定位航行试验检测结果显示,两组小鼠找到平台的潜伏期、游泳距离均无显著性差异（P > 0.05）;空间探索试验检测结果显示,两组小鼠的目标象限滞留时间占总时间的百分比和小鼠穿越平台区的次数也无显著性差异（P > 0.05）;但野生型小鼠的搜索策略优于神经鞘磷脂合成酶2缺乏小鼠（P < 0.05）。结论：神经鞘磷脂合成酶2缺乏影响小鼠的搜索策略,但不影响小鼠的空间学习记忆能力。     

韩氏针刺对海洛因依赖大鼠学习记忆及海马SYP表达的影响

目的：初步探讨韩氏针刺对海洛因依赖大鼠学习记忆的影响及其作用机制。方法：按逐日递增的原则皮下注射海洛因建立成瘾模型,利用Morris水迷宫测定大鼠成瘾后及针刺治疗后大鼠学习记忆的变化,免疫组化测定记忆相关蛋白突触素（SYP）在海马的表达。结果：①Morris水迷宫定位航行实验中,成瘾组逃避潜伏期较对照组明显延长（P〈0.05）,而针刺组较成瘾组明显缩短（P〈0.05）;空间探索实验中,成瘾组在第4象限搜索时间及第4象限游泳距离占总距离的百分比较对照组明显下降（P〈0．05）;而针刺组较成瘾组明显增加（P〈0．05）。②海马组织中SYP的表达成瘾组低于对照组（P〈0.05）,而针刺组明显高于成瘾组（P〈0．05）。结论：韩氏针刺戒断治疗可以部分恢复由于海洛因依赖导致的大鼠学习记忆能力的减退,增加海马内SYP表达。     

跑台运动促进幼龄大鼠学习能力

为了探讨跑台运动对幼龄大鼠学习能力的影响,实验采用5周龄Sprague-Dawley大鼠,随机分为安静对照组和跑台运动组,其中跑台运动组大鼠以低强度进行为期一周的跑台运动;然后使用Morris水迷宫,对两组大鼠的定位航行和空间探索能力进行分析。在定位航行实验中,运动组大鼠寻找到平台的潜伏期明显短于对照组（P〈0．05）;并且随着训练次数的增加,运动组大鼠的游泳速度明显高于对照组（P〈0．01）;另外,运动轨迹的弯曲度表明运动组大鼠还表现出了较强的寻找平台的动机以及对平台位置较为准确的空间定位能力。在空间探索实验中,两组大鼠的游泳速度并没有明显差异,从大鼠在各象限内穿越平台相应位置的次数来看,运动组大鼠在D象限穿越的次数高于对照组,但无统计学差异（P〉0．05）。上述结果提示,低强度的跑台运动在短时间内便可以明显提高幼龄大鼠的学习能力。     

恒定磁场对小鼠空间记忆形成的影响

目的：探讨不同照射时间的恒定磁场作用对小鼠空间记忆形成的影响.方法：应用水迷宫学习模型测定并对比4小时恒定磁场照射组、3小时恒定磁场照射组、2小时恒定磁场照射组和无磁场照射的正常对照组动物的空间记忆能力.结果：水迷宫学习训练的实验表明：第一个训练日中,4小时磁场处理组动物与正常对照组比较,动物到达水下平台所需时间延长,且具有显著性差异（P〈0.05）;3小时磁场处理组与正常对照组比较,动物到达水下平台所需时间缩短,且具有显著性差异（P〈0.05）;第二个训练日中,2小时或3小时磁场处理组与正常对照组比较,动物到达水下平台所需时间延长,且均具有显著性差异（P〈0.05）.第三、四、五连续3个训练日中,3组磁场处理组动物到达水下平台所需的时间与正常对照组相比较均不具有显著性差异（P〉0.05）.结论：一定时间的磁场处理对小鼠空间记忆的形成有促进或损伤作用,究竟是促进还是损伤有可能取决于一个作用“窗口”问题.     

大鼠缺血性脑损伤引起学习记忆障碍及心率变异性改变

本研究通过建立高脂缺血性脑损伤大鼠模型,进行水迷宫实验和心率变异性（heart rate variability,HRV）的功率谱分析,探讨脑损伤前后大鼠学习记忆的变化及缺血对自主神经的影响。23只成年雄性Wistar大鼠随机分为对照组（n=10）、高脂组（n=6）和高脂缺血组（n=7）。高脂组和高脂缺血组大鼠均饲以高脂饲料制成高血脂大鼠模型。各组大鼠进行水迷宫实验后,高脂缺血组用双侧颈总动脉结扎（2-VO）法制作缺血再灌注模型,同时记录心电图。7d后各组大鼠再次进行水迷宫实验和记录心电图,对HRV序列进行基于快速傅立叶转换（fast Fourier transformation,FFT）的功率谱分析。结果：（1）第一次水迷宫测试,3组大鼠空间探索实验和定位航行实验结果无统计学差异;第二次水迷宫实验,高脂缺血组与其它两组相比,空间探索实验中平台所在象限的记忆频度明显下降（P〈0．01）,定位航行实验中平台所在象限的记忆频度显著下降（P〈0．01）,10圆环记忆得分显著下降（P〈0．001）,但高脂组与对照组相比无明显差异。（2）高脂缺血组缺血后心率持续下降;缺血时HRV中频段功率（0．2加．6Hz）呈现明显下降的趋势,高频段功率（0．6-2．5Hz）缓慢下降,中频／高频功率比值明显下降（P〈0．05）。（3）缺血7d后高脂缺血组与高脂组相比,心率明显加快,HRV的中频段功率无显著变化,高频段功率明显下降,中频／高频功率比值显著增高（P〈0．05）。结果表明,缺血过程中高脂缺血组大鼠的自主神经活动降低,交感神经活动相对于迷走神经活动减弱。缺血7d后,由于海马区神经元对缺血敏感易受损,造成高脂缺血组大鼠学习记忆障碍,同时引发迷走神经活动下降,大鼠交感．迷走神经系统平衡失调。     

野生成年树鼩主要脏器重量及脏器系数的测定分析

目的对野生成年树鼩的体重和主要脏器重量进行测定,计算其脏器系数。方法测定60只野生成年树鼩体重及11个主要脏器重量,并计算其脏器系数。进行脏器重量、脏器系数的性别间比较分析及Kendall和谐系数分析。结果性别间比较心、肺重量差异极显著（P〈0.01）,脑、肾上腺、胰腺重量之间差异显著（P〈0.05）;肾上腺、胰腺系数差异有极显著性（P〈0.01）,心、肺、肾系数之间差异均达到了显著水平（P〈0.05）。Kendall和谐系数（W）分析表明,动物与其个体各主要器官整体发育协调性较好。结论野生成年树鼩心重量、肺重量、脑重量、肾上腺重量、胰腺重量、肾上腺系数、胰腺系数、心系数、肺系数、肾系数性别间存在差异。     

慢性疲劳综合征小鼠的空间学习和记忆功能降低

目的对比分析慢性疲劳综合征小鼠与正常小鼠之间空间学习记忆功能存在的差异性。方法采用复合刺激法复制慢性疲劳综合征(CFS)小鼠模型,随后采用Morris水迷宫检测CFS小鼠与正常组小鼠之间空间学习记忆功能存在的差异。结果模型组小鼠寻找隐藏平台的潜伏期、总路程、平均游泳速度及目标象限滞留时间占总时间的百分比均显著低于正常组(P0.05),正常组小鼠寻找隐藏平台主要采用空间搜索策略,而CFS小鼠主要采用重复环绕搜索策略。结论 CFS小鼠的空间学习和记忆功能降低。     

α-突触核蛋白对小鼠空间学习记忆能力的影响

目的:观察α-突触核蛋白(α-Synuclein,α-Syn)对小鼠空间学习记忆能力的影响。方法:以C57/B6野生型小鼠(Wild Type,WT)及α-Syn过表达转基因小鼠(Tg-α-Syn)为研究对象,采用Morris水迷宫(Morris water maze,MWM)中定位航行实验、空间探索实验以及可视平台实验,按照训练要求,记录两组小鼠游泳路径和完成任务的时间。结果:在定位航行试验中,随着训练时间的增加,两组小鼠的寻台潜伏期均缩短。同时,在训练第五天时,与WT组小鼠相比,Tg-α-Syn小鼠的寻台潜伏期明显延长(58.77±1.32 versus 17.34±6.44,*P0.05)。在空间探索实验中,与WT组小鼠相比,Tg-α-Syn小鼠在目标象限停留时间更短(17.91±2.14versus 5.59±4.98,*P0.05)。为了进一步证明Tg-α-Syn小鼠的空间记忆与学习能力下降是与海马相关,采用了可视平台实验,结果显示:两组小鼠的寻台潜伏期无显著性差异(P0.05),即Tg-α-Syn小鼠不存在运动障碍和视觉障碍。结论:α-Syn过表达可导致海马相关的空间记忆、学习能力受损。     

不同品系小鼠在三种常见抑郁检测方法中的行为学表现

目的探讨4种不同品系小鼠在3种实验（空场实验、悬尾实验及强迫游泳实验）中的行为学差异,为抗抑郁新药研究中的实验动物选择提供参考。方法利用空场实验检测C57BL/6、BALB/c、ICR、和昆明小鼠的自主活动能力和对新奇环境的探索能力;利用悬尾实验和强迫游泳实验检测它们在应激刺激下的行为绝望状态。结果在空场实验中,BALB/c、ICR和昆明小鼠的运动总路程、运动速度和运动时间明显高于C57BL/6小鼠（P〈0.05）,ICR和昆明小鼠的直立次数也明显高于C57BL/6小鼠（P〈0.05）;悬尾实验C57BL/6小鼠的不动时间显著长于其他3种品系小鼠（P〈0.05）,但是4种品系小鼠在强迫游泳实验中的不动时间差异无显著性。结论 C57BL/6小鼠自发活动量低,对新奇环境的探索能力差,并且在急性应激刺激下容易造成行为绝望,因此C57BL/6小鼠可能适合作为急性应激抑郁模型动物。     

水迷宫实验中三种品系小鼠学习记忆能力的比较

目的探讨三种品系小鼠在Morris水迷宫实验中的学习记忆能力差异,为与改善学习记忆能力相关新药研究的实验动物选择提供参考。方法选用C57BL/6小鼠、昆明种小鼠和ICR小鼠,进行定位航行实验(5d)、空间搜索实验(1d)和工作记忆实验(4d),考察其学习记忆能力。结果定位航行实验从第3天起C57BL/6小鼠的潜伏期明显小于昆明种小鼠和ICR小鼠(P0.01);空间搜索实验C57BL/6小鼠穿过原平台位置的次数、在原平台象限游程比率和时间比率均明显多于昆明种小鼠和ICR小鼠(P0.05);动物每天工作记忆实验的潜伏期随测试次数增加而缩短,C57BL/6小鼠缩短的较昆明种小鼠和ICR小鼠稍多。结论C57BL/6小鼠的空间参考记忆能力与工作记忆能力均优于昆明种小鼠和ICR小鼠,且非空间因素对其学习记忆能力的评价干扰较小,可作为优先选择的水迷宫实验动物。     

Spatial working memory in rats: no differences between the sexes

In a number of mammalian species, males appear to have superior spatial abilities to females. The favoured explanations for this cognitive difference are hormonal, with higher testosterone levels in males than females leading to better spatial performance, and evolutionary, where sexual selection has favoured males with increased spatial abilities for either better navigational skills in hunting or to enable an increased territory size. However, an alternative explanation for this sex difference focuses on the role of varying levels of oestrogen in females in spatial cognition (the 'fertility and parental care' hypothesis). One possibility is that varying oestrogen levels result in variation in spatial learning and memory so that, when tested across the oestrous cycle, females perform as well as males on days of low oestrogen but more poorly on days of high oestrogen. If day in the oestrous cycle is not taken into account then, across an experiment, any sex differences found would always produce male superiority. We used a spatial working memory task in a Morris water maze to test the spatial learning and memory abilities of male and female rats. The rats were tested across a number of consecutive days during which the females went through four oestrous cycles. We found no overall sex differences in latencies to reach a submerged platform in a Morris water maze but, on the day of oestrus (low oestrogen), females took an extra swim to learn the platform's location (a 100% increase over the other days in the cycle). Female swim speed also varied across the oestrous cycle but females were no less active on the day of oestrus. These results oppose the predictions of the fertility and parental care hypothesis.     

胎次、性别对成年小鼠海马齿状回神经发生及学习记忆的影响

目的探讨胎次、性别是否对成年小鼠海马齿状回神经发生及学习记忆产生影响。方法运用Morris水迷宫系统检测第1～3胎成年小鼠的学习记忆能力,腹腔注射BrdU,标记神经干细胞,检测不同胎次、性别小鼠海马齿状回中的神经发生的差异。结果 （1）在同性别、不同胎次成年小鼠间,第2胎的学习记忆能力（LMA）均显著地高于第1、3胎的,其影响规律为LMA2〉LMA1〉LMA3,且P〈0.05;在同胎次、不同性别成年小鼠间,雌性小鼠的LMA均高于雄性小鼠的,但其差异无显著性（P〉0.05）。（2）在同性别、不同胎次成年小鼠间,第2胎海马DG新生神经细胞的数量（N）均高于第1、3胎的,其影响规律分别为NF2〉NF3〉NF1和NM2〉NM1〉NM3,但其差异无显著性（P〉0.05）;在同胎次、不同性别成年小鼠间,雌性小鼠的N均高于雄性小鼠的,但其差异无显著性（P〉0.05）。结论胎次、性别对实验动物神经发生及学习记忆等方面产生的影响是肯定的。因此,在使用实验动物时,应予以充分考虑,尽量使用胎次、性别相同的。     

Static magnetic field exposure affects behavior and learning in rats

The present work investigated the behavioral effects of a moderate exposure (1 h per day for 5 consecutive days) to a static magnetic field (SMF, 128 mT) in male rats. SMF effects were evaluated in two sets of control and SMF-exposed rats. One set of animals was used for evaluation of SMF potential effects on emotional behaviors in the elevated plus maze and in the open field. The other set of animals was tested for learning and memory abilities in different procedures of the Morris water maze task. We found no significant difference between control and SMF-exposed rats in anxiety tests. However, the ratio of open arms time in the plus maze was reduced by half in SMF-exposed rats. In the Morris water maze, SMF-exposed rats were partially impaired during the initial learning task as well as in the retention task at one week. We conclude that static magnetic field exposure altered emotional behaviors in the plus maze and led to cognitive impairments, or at least to substantial attention disorders, in the Morris water maze.     

BALB/c和ICR小鼠的学习记忆能力等行为学研究

目的研究不同品系小鼠学习记忆能力的差异,为学习记忆的基础研究提供应用信息。方法80只BALB/c和80只ICR小鼠分别分为Morris水迷宫组、跳台组、穿梭组、ROTA-ROD组,每组20例,进行学习记忆能力及行动能力测试。结果水迷宫组在9轮水迷宫训练学习期BALB/c小鼠空间学习记忆能力没有明显提高。ICR小鼠从9轮水迷宫训练学习期的第4次开始,逃避潜伏期显著缩短,与前3次相比差异有显著性(P<0.001)。跳台组ICR和BALB/c小鼠训练前后5 min内错误次数及跳下潜伏期差异均具有显著性。穿梭组ICR小鼠学习期与记忆期主动逃避次数、被动逃避次数及电击时间的差异均有显著性,而BALB/c小鼠训练前后主动逃避次数、被动逃避次数及电击时间的差异均无显著性。ROTA-ROD组ICR小鼠的跑步动作维持时间显著高于BALB/c小鼠,其差异有显著性。结论以上结果提示在进行某些学习记忆实验时,使用ICR小鼠优于BALB/c小鼠。     

慢性束缚应激对SD和Wistar大鼠学习记忆能力的影响

目的探讨慢性束缚应激对Wistar、SD两种品系大鼠学习记忆能力的影响,为应激模型中实验动物的选择提供依据。方法对两种品系大鼠(Wistar、SD)采用每天束缚10 h,束缚28 d建立慢性应激模型。采用物体认知新物体识别实验和Morris水迷宫空间学习、工作记忆行为学检测方法,观察束缚应激对两种品系实验动物学习记忆能力的影响。结果束缚28 d后,物体识别实验中,Wistar、SD模型组的辨别指数(discrimination index,DI)均低于对照组,但只有SD两组间差异存在显著性(P0.05);水迷宫空间学习阶段,SD模型组潜伏期高于对照组,第5天差异有显著性(P0.05),而Wistar模型组与对照组间的潜伏期没有差异;水迷宫工作记忆阶段,SD大鼠模型组与正常组比较,潜伏期显著增加(P0.05),Wistar模型大鼠的潜伏期与对照组比较没有显著差异。结论新物体识别实验和水迷宫实验,这两种反应动物不同学习记忆能力的行为学实验结果都表明,慢性束缚应激(10 h,28 d)对SD大鼠学习记忆能力的损伤较Wistar大鼠明显。SD大鼠可能更适合作为慢性应激所致学习记忆损伤动物模型。     

Roles of oxytocin in spatial learning and memory in the nucleus basalis of Meynert in rats

The present study was performed to explore the role of oxytocin (OT) in spatial learning and memory in the nucleus basalis of Meynert (NBM) of rats. The latency, distance and swimming path to find the platform were tested by Morris water maze and recorded by a video camera connected to a computer. Intra-NBM injections of 2 or 10 nmol of OT, but not 0.2 nmol of OT, induced significant increase on the latency of spatial learning. Rats receiving intra-NBM administrations of 2 or 10 nmol of OT showed a more random search pattern. There were no significant changes in the swimming speed in Morris water maze test after the injection of OT. Furthermore, the impaired effect of OT on the latency of spatial learning was blocked by intra-NBM injection of the selective OT antagonist Atosiban, indicating that the effect of OT was mediated by OT receptor in the NBM of rats. Moreover, there were no influences of OT or Atosiban on the retention performance in rats. The results suggest that OT plays an inhibitory role in spatial learning in the NBM; the effect is mediated by OT receptor.     

Gender-based changes in cognition and emotionality in a new rat model of epilepsy

Summary. Epilepsy research relies heavily on animal models that mimic some, or all, of the clinical symptoms observed. We have previously described a new developmental rat model of epilepsy that demonstrates both behavioural seizures and changes in hippocampal morphology. In the current study we investigated whether these rats also show changes in cognitive performance as measured using the Morris water maze task, and emotionality as measured using the Elevated plus maze task. In the water maze, significant differences between male and female rats were found in several performance variables regardless of treatment. In addition, female but not male rats, treated neonatally with domoic acid had significant impairments in learning new platform locations in the water maze. In the elevated plus maze, a significant proportion of female rats spent more time in the open arm of the maze following prior exposure to the maze whereas this effect was not seen in male rats. We conclude that perinatal treatment with low doses of domoic acid results in significant gender-based changes in cognition and emotionality in adult rats.     

Transgenic expression of androgen receptors improves spatial memory retention in both sham-irradiated and 137Cs gamma-irradiated female mice

Using a water maze, it has been shown that both wild-type and apoE4-expressing female mice are at greater risk of developing age-related hippocampal-dependent impairments in spatial learning and memory than age-matched male mice of the same genotype. In addition, apoE4-expressing female mice were more sensitive to 137Cs gamma-radiation-induced impairment in spatial learning and memory than age-matched male mice of the same genotype. These findings imply that androgen receptors (ARs) contribute to spatial learning and memory, posing the question as to whether transgenic expression of AR in female mice might modulate hippocampal-dependent learning and memory under baseline conditions and after local brain irradiation. Hippocampal-dependent novel location recognition was comparable in wild-type and AR-Tg female mice. This function was impaired after irradiation in AR-Tg but not wild-type mice. In contrast, sham-irradiated wild-type and AR-Tg female mice showed hippocampal-independent novel location recognition, and this was not affected by radiation. After the second day of hidden platform training, in a water maze probe trial, sham-irradiated and irradiated AR-Tg female mice showed spatial memory retention but irradiated wild-type mice did not. After the third day of hidden platform training, only irradiated wild-type female mice did not show spatial memory retention in the water maze probe trial. Both sham-irradiated and irradiated wild-type and AR-Tg female mice showed passive avoidance learning and memory. These data support an important role for AR in spatial memory retention in water maze probe trials in female mice under baseline conditions and after cranial irradiation.