负性情绪对不同视野条件下工作记忆的影响

目的:研究结合延迟样本匹配任务和分视野范式,探讨负性情绪对言语和空间工作记忆的影响。方法:32名大学本科生参加实验,在中性和负性情绪图片呈现阶段,所有被试完成言语和空间工作记忆任务各160个trial。结果:言语工作记忆任务在右视野呈现时正确率较高,反应时较短,而空间工作记忆任务则在左视野呈现时表现出相似的反应优势;负性情绪状态下的工作记忆表现均优于中性情绪状态。结论:言语及空间工作记忆分别具有左、右半球的加工优势,且负性情绪对工作记忆具有促进作用。     

Rats' memory for event duration: differential effects of delaying the discriminative choice cue as opposed to the opportunity to execute the choice response

Rats were trained to discriminate short or long durations of houselight illumination using a choice procedure. During the test phase of each trial, the left and right levers were presented with an auditory cue above one of them on (cued lever) while the other was off (uncued lever). The auditory cue was presented immediately after sample offset and the levers were inserted after the auditory cue had been presented for 2 s. For half of the rats, the correct response following the short sample was to press the cued lever, while following the long sample, it was to press the uncued lever. This was reversed for the remaining rats. Following acquisition of the discrimination, two different types of delay tests were administered. In the first set, the delay between offset of the sample and onset of the auditory cue was manipulated (Cue Delay Test). In the second set, the delay between onset of the auditory cue and entry of the levers into the chamber was manipulated (Response Delay Test). Cue Delay testing resulted in a choose-long bias at the longer delays. Response Delay testing did not result in a systematic response bias and there was little forgetting over the delay interval. These data suggest that the rats did not stop the internal clock when the nominal sample was offset, but allowed it to keep running until the auditory cue was presented. The data from the Response Delay Test indicate that either a response decision was made based on the clock reading as soon as the auditory cue was presented, or the clock reading itself was retained over the delay with no subjective shortening and little forgetting.     

Haploinsufficiency of the arginine-vasopressin gene is associated with poor spatial working memory performance in rats

Behavioral pharmacological studies have implicated a role for the neurophysin arginine-vasopressin in learning and memory. Vasopressin, and its analogues, can produce either improvements or impairments in mnemonic functions, effects that depend upon the agent administered, the memory process measured and the task employed. As recent data have implicated vasopressin in regulating the cognitive functions of the prefrontal cortex, we sought to determine whether changes in vasopressinergic tone would affect a form of memory that is dependent upon this brain region. To that end, we used a genetic approach to examine how haploinsufficiency of the vasopressin gene affects working memory performance. Specifically, we tested a naturally occurring null-mutant rat on an operant delayed-non-match-to-position task. Male and female heterozygous and wild-type rats were trained to perform this working memory task, and the effects of varying the delay across which they had to maintain task information were systematically varied. Although vasopressin-deficient rats omitted fewer trials and completed trials more quickly, they exhibited delay-dependent deficits of choice accuracy. The genotype effects were not modified by sex. Collectively, these data indicate that even partial vasopressin deficiency can trigger deficits of spatial working memory performance and add to the growing body of results supporting a regulatory control of neocortical-dependent cognitive functions by this neurohormone.     

Low-level exposure to pulsed 900 MHz microwave radiation does not cause deficits in the performance of a spatial learning task in mice

There is some concern that short-term memory loss or other cognitive effects may be associated with the use of mobile cellular telephones. In this experiment, the effect of repeated, acute exposure to a low intensity 900 MHz radiofrequency (RF) field pulsed at 217 Hz was explored using an appetitively-motivated spatial learning and working memory task. Adult male C57BL/6J mice were exposed under far field conditions in a GTEM cell for 45 min each day for 10 days at an average whole-body specific energy absorption rate (SAR) of 0.05 W/kg. Their performance in an 8-arm radial maze was compared to that of sham-exposed control animals. All behavioral assessments were performed without handlers having knowledge of the exposure status of the animals. Animals were tested in the maze immediately following exposure or after a delay of 15 or 30 min. No significant field-dependent effects on performance were observed in choice accuracy or in total times to complete the task across the experiment. These results suggest that exposure to RF radiation simulating a digital wireless telephone (GSM) signal under the conditions of this experiment does not affect the acquisition of the learned response. Further studies are planned to explore the effects of other SARs on learned behavior. Bioelectromagnetics 21:151-158, 2000. Published 2000 Wiley-Liss, Inc.     

Dihydrotestosterone modulates spatial working-memory performance in male mice

Androgens affect cognitive processes in both humans and animals. The effects of androgens may be limited to certain cognitive domains, specifically spatial memory, but this hypothesis remains elusive. Here, we tested castrated and sham-operated mice in various behavioral tasks to ask whether androgens affect multiple or specific cognitive domains in male mice. Castration impaired spatial working memory performance in the delayed matching to place water maze task following a 1-h, but not a 1-min, retention interval, as has been reported for rats. In contrast, castration had no effect on novel object recognition memory, spatial reference memory in the water maze, motor coordination, or passive avoidance memory. Castration increased anxiety-like behavior in the open field test, but not the elevated zero maze. Finally, we assessed the effects of androgen replacement with non-aromatizable dihydrotestosterone on spatial working memory following various retention intervals. Dihydrotestosterone recovered spatial memory performance following a 24-h, but not a 1-h retention interval, and had no effect at other retention intervals. These data support that in male mice androgens specifically affect spatial working memory performance, and that the neurobiological processes underlying spatial memory formation may be differentially affected by androgens.     

Evidence for Anomalous Network Connectivity during Working Memory Encoding in Schizophrenia: An ICA Based Analysis

Background

Numerous neuroimaging studies report abnormal regional brain activity during working memory performance in schizophrenia, but few have examined brain network integration as determined by “functional connectivity” analyses.

Methodology/Principal Findings

We used independent component analysis (ICA) to identify and characterize dysfunctional spatiotemporal networks in schizophrenia engaged during the different stages (encoding and recognition) of a Sternberg working memory fMRI paradigm. 37 chronic schizophrenia and 54 healthy age/gender-matched participants performed a modified Sternberg Item Recognition fMRI task. Time series images preprocessed with SPM2 were analyzed using ICA. Schizophrenia patients showed relatively less engagement of several distinct “normal” encoding-related working memory networks compared to controls. These encoding networks comprised 1) left posterior parietal-left dorsal/ventrolateral prefrontal cortex, cingulate, basal ganglia, 2) right posterior parietal, right dorsolateral prefrontal cortex and 3) default mode network. In addition, the left fronto-parietal network demonstrated a load-dependent functional response during encoding. Network engagement that differed between groups during recognition comprised the posterior cingulate, cuneus and hippocampus/parahippocampus. As expected, working memory task accuracy differed between groups (p<0.0001) and was associated with degree of network engagement. Functional connectivity within all three encoding-associated functional networks correlated significantly with task accuracy, which further underscores the relevance of abnormal network integration to well-described schizophrenia working memory impairment. No network was significantly associated with task accuracy during the recognition phase.

Conclusions/Significance

This study extends the results of numerous previous schizophrenia studies that identified isolated dysfunctional brain regions by providing evidence of disrupted schizophrenia functional connectivity using ICA within widely-distributed neural networks engaged for working memory cognition.     

Roles of dynamic linkage of stable attractors across cortical networks in recalling long-term memory

 We propose a neural network model for a category-association task. By simulating the model, neuronal relevance of cortical interactions to recalling long-term memory was investigated. The model consists of the left and right hemispheres, each of which has IT (inferotemporal cortex) and PC (prefrontal cortex) networks. Information about visual features and their categories were encoded into point attractors of the IT and PC networks, respectively. In the task, the IT network of the right hemisphere was stimulated with a cue feature. After a delay period, the IT network of the left hemisphere was simultaneously stimulated with the choice feature and an irrelevant feature. The cue and choice features belong to the same category, while the irrelevant feature belongs to another category. To complete the task, the IT network must select the point attractor corresponding to the choice feature. We demonstrate that the top-down pathway (PC-to-IT) triggers the retrieval of long-term memory of the choice feature from the IT, and the bottom-up pathway (IT-to-PC) contributes to the maintenance of the retrieved memory during the delay period. The key mechanism for the retrieval and maintenance of that memory is the dynamic linkage of attractors across separate cortical networks. We show that a single hemisphere is sufficient for the memory retrieval, but it is advantageous to use the two hemispheres because the retrieved memory is thereby retained with greater reliability until the brain chooses the choice feature. Received: 4 April 2001 / Accepted in revised form: 17 September 2002 / Published online: 20 January 2003 Correspondence to: O. Hoshino (e-mail: hoshino@cc.oita-u.ac.jp, Tel.: +81-97-554-7301, Fax: +81-97-554-7507)     

The Right Frontopolar Cortex Is Involved in Visual-Spatial Prospective Memory

The involvement of frontopolar cortex in mediating prospective memory processes has been evidenced by various studies, mainly by means of neuroimaging techniques. Recently, one transcranial magnetic stimulation study documented that transient inhibition of left Brodmann Area (BA) 10 impaired verbal prospective memory. This result raises the issue of whether the BA 10 involvement in prospective memory functioning may be modulated by the physical characteristics of the stimuli used. The present study aimed to investigate the role of the frontopolar cortex in visual-spatial PM by means of the application of inhibitory theta-burst stimulation. Twelve volunteers were evaluated after inhibitory theta-burst stimulation over left BA 10, right BA10 and CZ (control condition). In the prospective memory procedure, sequences of four spatial positions (black squares) each were presented. During the inter-sequence delay, subjects had to reproduce the sequence in the observed order (ongoing task forward) or the reverse order (backward). At the occurrence of a target position, subjects had to press a key on the keyboard (prospective memory score). Recall and recognition of the target positions were also tested. We found that prospective memory accuracy was lower after theta-burst stimulation over right BA10 than CZ (p<0.01), whereas it was comparable in left BA10 and CZ conditions. No significant difference was found among the three conditions on recall and recognition of target positions and on ongoing task performance. Our findings provide a novel strong evidence for a specific involvement of right frontopolar cortex in visual-spatial prospective memory. In the context of previous data providing evidence for left BA 10 involvement in verbal prospective memory, our results also suggest material-specific lateralization of prospective memory processes in BA 10.     

Modulating Memory Performance in Healthy Subjects with Transcranial Direct Current Stimulation Over the Right Dorsolateral Prefrontal Cortex

Objective

The role of the Dorsolateral Prefrontal Cortex (DLPFC) in recognition memory has been well documented in lesion, neuroimaging and repetitive Transcranial Magnetic Stimulation (rTMS) studies. The aim of the present study was to investigate the effects of transcranial Direct Current Stimulation (tDCS) over the left and the right DLPFC during the delay interval of a non-verbal recognition memory task.

Method

36 right-handed young healthy subjects participated in the study. The experimental task was an Italian version of Recognition Memory Test for unknown faces. Study included two experiments: in a first experiment, each subject underwent one session of sham tDCS and one session of left or right cathodal tDCS; in a second experiment each subject underwent one session of sham tDCS and one session of left or right anodal tDCS.

Results

Cathodal tDCS over the right DLPFC significantly improved non verbal recognition memory performance, while cathodal tDCS over the left DLPFC had no effect. Anodal tDCS of both the left and right DLPFC did not modify non verbal recognition memory performance.

Conclusion

Complementing the majority of previous studies, reporting long term memory facilitations following left prefrontal anodal tDCS, the present findings show that cathodal tDCS of the right DLPFC can also improve recognition memory in healthy subjects.     

Left-right asymmetry defect in the hippocampal circuitry impairs spatial learning and working memory in iv mice

Although left-right (L-R) asymmetry is a fundamental feature of higher-order brain function, little is known about how asymmetry defects of the brain affect animal behavior. Previously, we identified structural and functional asymmetries in the circuitry of the mouse hippocampus resulting from the asymmetrical distribution of NMDA receptor GluR ε2 (NR2B) subunits. We further examined the ε2 asymmetry in the inversus viscerum (iv) mouse, which has randomized laterality of internal organs, and found that the iv mouse hippocampus exhibits right isomerism (bilateral right-sidedness) in the synaptic distribution of the ε2 subunit, irrespective of the laterality of visceral organs. To investigate the effects of hippocampal laterality defects on higher-order brain functions, we examined the capacity of reference and working memories of iv mice using a dry maze and a delayed nonmatching-to-position (DNMTP) task, respectively. The iv mice improved dry maze performance more slowly than control mice during acquisition, whereas the asymptotic level of performance was similar between the two groups. In the DNMTP task, the iv mice showed poorer accuracy than control mice as the retention interval became longer. These results suggest that the L-R asymmetry of hippocampal circuitry is critical for the acquisition of reference memory and the retention of working memory.     

Rat spatial memory tasks adapted for humans: characterization in subjects with intact brain and subjects with selective medial temporal lobe thermal lesions

In the present paper we describe five tests, 3 of which were designed to be similar to tasks used with rodents. Results obtained from control subjects, patients with selective thermo-coagulation lesions to the medial temporal lobe and results from non-human primates and rodents are discussed. The tests involve memory for spatial locations acquired by moving around in a room, memory for objects subjects interacted with, or memory for objects and their locations. Two of the spatial memory tasks were designed specifically as analogs of the Morris water task and the 8-arm radial-maze tasks used with rats. The Morris water task was modeled by hiding a sensor under the carpet of a room (Invisible Sensor Task). Subjects had to learn its location by using an array of visual cues available in the room. A path integration task was developed in order to study the non-visual acquisition of a cognitive representation of the spatial location of objects. In the non-visual spatial memory task, we blindfolded subjects and led them to a room where they had to find 3 objects and remember their locations. We designed an object location task by placing 4 objects in a room that subjects observed for later recall of their locations. A recognition task, and a novelty detection task were given subsequent to the recall task. An 8-arm radial-maze was recreated by placing stands at equal distance from each other around the room, and asking subjects to visit each stand once, from a central point. A non-spatial working memory task was designed to be the non-spatial equivalent of the radial maze. Search paths recorded on the first trial of the Invisible Sensor Task, when subjects search for the target by trial and error are reported. An analysis of the search paths revealed that patients with lesions to the right or left hippocampus or parahippocampal cortex employed the same type of search strategies as normal controls did, showing similarities and differences to the search behavior recorded in rats. Interestingly, patients with lesions that included the right parahippocampal cortex were impaired relative to patients with lesions to the right hippocampus that spared the parahippocampal cortex, when recall of the sensor was tested after a 30 min delay (Bohbot et al. 1998). No differences were obtained between control subjects and patients with selective thermal lesions to the medial temporal lobe, when tested on the radial-maze, the non-spatial analogue to the radial-maze and the path integration tasks. Differences in methodological procedures, learning strategies and lesion location could account for some of the discrepant results between humans and non-human species. Patients with lesions to the right hippocampus, irrespective of whether the right parahippocampal cortex was spared or damaged, had difficulties remembering the particular configuration and identity of objects in the novelty detection of the object location task. This supports the role of the human right hippocampus for spatial memory, in this case, involving memory for the location of elements in the room; learning known to require the hippocampus in the rat.     

Species differences between rats and pigeons in choices with probabilistic and delayed reinforcers

An adjusting-delay procedure was used to study rats' choices with probabilistic and delayed reinforcers, and to compare them with previous results from pigeons. A left lever press led to a 5-s delay signaled by a light and a tone, followed by a food pellet on 50% of the trials. A right lever press led to an adjusting delay signaled by a light followed by a food pellet on 100% of the trials. In some conditions, the light and tone for the probabilistic reinforcer were present only on trials that delivered food. In other conditions, the light and tone were present on all trials that the left lever was chosen. Similar studies with pigeons [Mazur, J.E., 1989. Theories of probabilistic reinforcement. J. Exp. Anal. Behav. 51, 87-99; Mazur, J.E., 1991. Conditioned reinforcement and choice with delayed and uncertain primary reinforcers. J. Exp. Anal. Behav. 63, 139-150] found that choice of the probabilistic reinforcer increased dramatically when the delay-interval stimuli were omitted on no-food trials, but this study found no such effect with the rats. In other conditions, the probability of food was varied, and comparisons to previous studies with pigeons indicated that rats showed greater sensitivity to decreasing reinforcer probabilities. The results support the hypothesis that rats' choices in these situations depend on the total time between a choice response and a reinforcer, whereas pigeons' choices are strongly influenced by the presence of delay-interval stimuli.     

Lateralization and unilateral transfer of spatial memory in marsh tits: are two eyes better than one?

Two previous experiments on food storing and one-trial associative learning in marsh tits (Clayton 1992a; Clayton and Krebs 1992) demonstrate that information coming into the brain from the left eye disappears from the left eye system between 3 and 24 h after memory formation, whereas that coming into the brain from the right eye remains stable within the right eye system for at least 51 h after memory formation. Performance after a 7 h retention interval appears to represent an intermediate stage in which the information is no longer accessible to the left eye system but is not yet available to the right eye system, suggesting a unilateral transfer of memory. The experiments reported here further investigated lateralization and unilateral transfer of memory in food-storing marsh tits, Parus palustris, using the technique of monocular occlusion. Birds were tested for their ability to retrieve stored seeds after retention intervals of 3, 7 and 24 h under 4 different occlusion treatments. Two predictions were tested: (a) with right eye occlusion during storage, birds should show better memory performance after 3 and 24 h than after 7 h and (b) memory should be more accurate when both eyes are used during storage than with monocular occlusion. The first prediction, which arises from the fact that memory is transferred from the left to the right eye system at about 7 h and is inaccessible during the transfer, was supported by the data. The second prediction, however, was not supported. Previous work has shown that in marsh tits the two eye systems remember preferentially different aspects of the stimulus: the left eye system responds to spatial position and the right eye system to object-specific cues. It is possible that the failure to find superior performance in binocular tests was because the task could be solved by either spatial or object-specific memory.     

Cognitive effects of radiation emitted by cellular phones: The influence of exposure side and time

This study examined the time dependence effects of exposure to radiofrequency radiation (RFR) emitted by standard GSM cellular phones on the cognitive functions of humans. A total of 48 healthy right‐handed male subjects performed a spatial working memory task (that required either a left‐hand or a right‐hand response) while being exposed to one of two GSM phones placed at both sides of the head. The subjects were randomly divided into three groups. Each group was exposed to one of three exposure conditions: left‐side of the head, right‐side, or sham‐exposure. The experiment consisted of 12 blocks of trials. Response times (RTs) and accuracy of the responses were recorded. It was found that the average RT of the right‐hand responses under left‐side exposure condition was significantly longer than those of the right‐side and sham‐exposure groups averaged together during the first two time blocks. These results confirmed the existence of an effect of exposure on RT, as well as the fact that exposure duration (together with the responding hand and the side of exposure) may play an important role in producing detectable RFR effects on performance. Differences in these parameters might be the reason for the failure of certain studies to detect or replicate RFR effects. Bioelectromagnetics 30:198–204, 2009. © 2008 Wiley‐Liss, Inc.     

Rats' memory for event duration in delayed matching-to-sample with nonspatial comparison response alternatives

Previous research has suggested that using stationary and moving levers as nonspatial response alternatives can significantly enhance the speed of acquiring a temporal discrimination in rats. In Experiment 1, rats were trained to discriminate 2 and 8s of magazine light illumination by responding to either a stationary lever or a moving lever with a cue light illuminated above it. Rats learned to discriminate event durations at a high level of accuracy after 25 sessions of training. During subsequent delay tests, rats exhibited a strong choose-long bias, indicating that they were timing from the onset of the magazine light until the entry of levers into the chamber. This occurred regardless of whether intertrial intervals and delay intervals were dark or illuminated. On test trials in which the sample was omitted, rats responded as if the short sample had been presented. In Experiment 2, the rats received extensive training with dark and illuminated variable delay intervals (1-4 s). However, they continued to exhibit a tendency to time from the onset of the magazine light until entry of the levers into the chamber. Although the use of stationary/uncued and moving/cued levers as response alternatives enhanced the speed of acquisition of the event duration discrimination in rats, additional procedural modifications will be necessary to prevent rats from timing during the delay interval.     

Computer simulation of pigeons' performance on a spatial memory task

Delayed matching of key location is a useful paradigm for the study of pigeons' short-term memory for a spatial location. On each trial a randomly selected key from a matrix of keys is lit briefly as a sample and followed by a retention interval. During the ensuing choice period the sample and one of the non-sample keys are lit; choice of the sample is correct and rewarded whereas choice of the distractor key is not. The computer simulation of performance on this task is based on a simple model: We assume that the pigeon has knowledge of the location of the keys stored in a map-like reference memory. We also assume that short-term memory involves an attention focus or “pointer” that “drifts” on the surface of this map. The pointer migrates from a randomly determined position during the intertrial interval towards the location of the sample when this stimulus is presented. It wanders randomly from its previous position when this cue is no longer present in the retention interval. During the test for retention the bird selects the location (i.e., sample or distractor) closer to the location of the pointer on the map of the matrix. The simulation successfully reproduced several of the phenomena observed in delayed matching of location experiments and provided an account of some hitherto perplexing results. As well, the model successfully predicted some new empirical data.     

Impulsive Choice Predicts Poor Working Memory in Male Rats

A number of maladaptive behaviors and poor health outcomes (e.g., substance abuse, obesity) correlate with impulsive choice, which describes the tendency to prefer smaller, immediate rewards in lieu of larger, delayed rewards. Working memory deficits are often reported in those diagnosed with the same maladaptive behaviors. Human studies suggest that impulsive choice is associated with working memory ability but, to date, only one study has explored the association between working memory and impulsive choice in rats and no relation was reported. The current study reevaluated the association between working memory and impulsive choice in 19 male Long-Evans rats. Psychophysical adjusting procedures were used to quantify working memory (titrating-delay match-to-position procedure) and impulsive choice (adjusting delay procedure). Rats were partitioned into low- and high-impulsive groups based on performance in the impulsive choice task. Low-impulsive rats performed significantly better in the working memory assessment. Across all rats, impulsive choice was negatively correlated with working memory performance. These findings support the hypothesis that prefrontal cortex function, specifically, working memory, is related to impulsive choice. Future research might profitably examine the experimental variables designed to influence working memory to evaluate the effects of these variables on impulsive choice and maladaptive behaviors with which it is correlated.     

Event-related potentials during paired associate memory paradigm

We have studied event-related potentials (ERPs) during a visual paired association task with delayed discrimination in 10 normal right-handed subjects. After subjects completely memorized 4 pairs of figures during a learning period, they were presented with each cue (S1) and asked to judge whether the following figure (S2) formed one of the memorized pairs or not. A choice reaction task with delay was used for control in an attempt to identify brain activity specifically related to memory function. ERPs were recorded from 21 scalp electrodes and those occurring between the S1 and S2 presentation were analyzed. Two ERP components associated with memory function were identified in the difference waveform between the responses in the paired association task and those in the choice reaction task. One was a posterior positive component which appeared between 390 ms and 1100 ms after the S1 presentation and the other was a sustained frontal negative component which began at about 1100 ms after S1 and ended just before the S2 presentation. Both potentials were distributed predominantly on the scalp overlying the left hemisphere. It is postulated that the early posterior positive component may reflect retrieval of information from association memory, whereas the late frontal negativity may reflect retention of information in working memory.     

Female mini-pig performance of temporal response differentiation, incremental repeated acquisition, and progressive ratio operant tasks

Increased knowledge of the cognitive abilities of mini-pigs is needed due to their increasing use in behavioral neuroscience research. Here, six female Yucatan mini-pigs performed tasks thought to measure timing behavior (temporal response differentiation, TRD), learning (incremental repeated acquisition, IRA), and motivation (progressive ratio, PR). Daily 30-min sessions for food reinforcers required a lever press be maintained for at least 10 but no longer than 14s (TRD), learning a new sequence of lever presses each test day (IRA) or an escalating number of presses for subsequent reinforcers (PR). All animals performed PR two days/week while three performed TRD five days/week and the other three performed IRA five days/week. Over the four test weeks, no animal completed TRD training and only one appeared to progress. For this task, lever press maintenance appeared difficult since by choice, the pigs used a front hoof, rather than the snout, to press the lever. IRA subjects showed gradually increasing performance with response rates comparable to those of rats but below those of children and monkeys and accuracy below that for rats. PR response rates were higher than those typically reported for rats, but lower than for adult rhesus monkeys or children. Physical differences in the way that each species responds likely account for these differences.     

昆明小鼠物体识别模型的建立及其在检测化学药物对记忆损伤中的应用

本研究的主要目的是建立昆明小鼠物体识别模型并评价该模型在安全药理学研究中的潜在应用价值。研究了昆明小鼠物体识别记忆随时间而减弱的特性,在训练结束后4h或1h,检测昆明小鼠的物体识别记忆,并评价了东莨胆碱对昆明小鼠物体识别记忆的影响。结果表明:1h间隔组昆明小鼠熟悉期探究物体的时间差和测试期探究物体的时间差存在显著差异(P<0.05),昆明小鼠在训练结束后1h记忆保持良好,可以进行物体识别;东莨胆碱组昆明小鼠熟悉期探究物体的时间差和测试期探究物体的时间差比较(P>0.05),没有显著性差异。因此,东莨胆碱损伤了昆明小鼠的物体识别记忆。用昆明小鼠建立的物体识别模型具有简单、快速、可靠等特点,在安全药理学研究中可用于检测化学药物对记忆的损伤。