OBJECTIVETo observe the effects of repeated subconvulsive electrical stimuli to the hippocampus on the emotional behavior and spatial learning and memory ability in rats.

METHODSOne hundred and eight male Wistar rats were randomized into 3 groups. Animals in group SE (n = 42) were given subconvulsive electrical stimulation to the hippocampus through a constant pulsating current of 100 mu A with an intratrain frequency of 25 Hz, pulse duration of 1 millisecond, train duration of 10 seconds and interstimulus interval of 7 minutes, 8 times a day, for 5 days. In the electrode control group or CE group (n = 33), animals were implanted with an electrode in the hippocampus, but were not stimulated. Group NC (n = 33) animals received no electrode or any stimulation. The emotional behavior of experimental rats was examined by activity in an unfamiliar open field and resistance to capture from the open field, while the spatial learning and memory ability was measured during training in a Morris water maze.

RESULTSThe stimulated rats tested 1 month after the last round of stimulation displayed substantial decreases in open field activity (scale: 10.4 +/- 2.3, P < 0.05) and increases in resistance to capture (scale: 2.85 +/- 0.56, P < 0.01). The amount of time for rats in group SE to find the platform (latency) as a measurement for spatial bias was prolonged (29 +/- 7) seconds after 15 trials in the water maze, P < 0.05). The experimental rats swam aimlessly in all four pool quadrants during the probe trial in the Morris water maze.

CONCLUSIONSFollowing repeated subconvulsive electrical stimuli to the hippocampus, rats displayed long-lasting significant abnormalities in emotional behavior, increased anxiety and defensiveness, enhanced ease to and delayed habituation to startlement, transitory spatial learning and memory disorder, which parallels many of the symptoms in posttraumatic stress disorder patients.

Animals ; Electric Stimulation ; adverse effects ; Emotions ; physiology ; Hippocampus ; physiology ; Learning ; physiology ; Male ; Memory ; physiology ; Rats ; Rats, Wistar ; Space Perception ; physiology

Event-related potentials (ERP) is a good temporal resolution method to study the mechanism of visual field in brain. With the development of technique of high-density recording and brain imaging, the ERP is widely used in the location of the brain function. This article reviews the methods, results and primary conclusions in the field, and suggests several perspectives for the future research and application of ERP in the forensic science.
Attention/physiology* ; Brain/physiology* ; Evoked Potentials/physiology* ; Forensic Medicine ; Humans ; Photic Stimulation/methods* ; Space Perception/physiology* ; Visual Fields/physiology* ; Visual Perception

PURPOSE: The purpose of this study was to investigate the effects of contrast display exposure on neuronal directional and spatial frequency tuning. Neuronal responses were recorded from ninety-four neurons in cortical areas 17 and 18 in two adult cats. METHODS: A multi-channel microelectrode was implanted in cortical areas 17 and 18 of two paralyzed and anaesthetized cats. Various drifting sinusoidal grating contrast displays were presented to one of the cats' eyes in the visual field. Contour plots based on the neuronal responses to the drifting sinusoidal grating displays using various contrasts (i.e., 0.4, 0.7, and 1.0) and velocities (i.e., 4.6, 13.9, 23.1, 32.3, 41.5, 50.8, and 60.0 deg/sec) were plotted as a function of the spatial frequency and the direction associated with each velocity and contrast used. RESULTS: Five parameters were extracted from these contour plots: 1) optimum response, 2) preferred direction, 3) optimum spatial frequency, 4) directional tuning width, and 5) spatial frequency bandwidth. To determine the optimal velocity, each parameter was plotted against each of the specific display contrasts used, and a 'best fit' line was established. Response amplitudes were dependent on the type of contrast utilized; however, the spatial frequency and directional tuning properties were stable for the cortical neurons assessed. CONCLUSIONS: The results of the presentation of different contrasts on neuronal directional and spatial frequency tuning are consistent with behavioral results when medium and high contrast displays are used.
Animals ; Cats ; Contrast Sensitivity/*physiology ; Electrophysiological Phenomena ; Orientation/physiology ; Photic Stimulation/methods ; Sen ; Space Perception/physiology ; Visual Cortex/cytology/*physiology

Attention ; physiology ; Female ; Functional Laterality ; physiology ; Humans ; Middle Aged ; Neuropsychological Tests ; Prosopagnosia ; complications ; Space Perception ; physiology ; Stroke ; complications

Similar to the visual dual-pathway model, neurophysiological studies in non-human primates have suggested that the dual-pathway model is also applicable for explaining auditory cortical processing, including the ventral "what" pathway for object identification and the dorsal "where" pathway for spatial localization. This review summarizes evidence from human neuroimaging studies supporting the dual-pathway model for auditory cortical processing in humans.
Animals ; Auditory Cortex ; anatomy & histology ; physiology ; Auditory Pathways ; anatomy & histology ; physiology ; Auditory Perception ; physiology ; Humans ; Macaca ; anatomy & histology ; physiology ; Models, Neurological ; Neurons ; physiology ; Pitch Discrimination ; physiology ; Sound Localization ; physiology ; Space Perception ; physiology

PURPOSE: To examine the prevalence of visual field deterioration in contralateral eyes of patients with worsening open-angle glaucoma and to evaluate the spatial concordance of visual field deterioration between both eyes. METHODS: One hundred sixteen open-angle glaucoma patients who underwent 8 or more visual field examinations over > or =6 years of follow-up were included. The rates of the fast and slow components of visual field decay for each of 52 visual field test locations were calculated with point-wise exponential regression analysis. The spatial concordance of visual field deterioration in contralateral eyes was evaluated with a concordance ratio (calculated as the number of overlapping locations divided by the total number of deteriorating locations) and by comparing the rate of decay in corresponding modified glaucoma hemifield test clusters. RESULTS: The average visual field mean deviation (+/-standard deviation [SD]) was -8.5 (+/-6.4) dB and the mean (+/-SD) follow-up time was 9.0 (+/-1.6) years. Sixty-three patients had mild damage, 23 had moderate damage, and 30 had severe damage. The mean concordance ratio (+/-SD) was 0.46 (+/-0.32) for the mild group, 0.33 (+/-0.27) for the moderate group, and 0.35 (+/-0.21) for the severe group. Thirty-one patients (27%) had deterioration in concordant locations (p < 0.05). Visual field deterioration was greater in the superior hemifield than the inferior hemifield (p < 0.05) when evaluated with both the concordance ratio and modified glaucoma hemifield test cluster analysis methods. CONCLUSIONS: There is only fair spatial concordance with regard to visual field deterioration between the both eyes of an individual. We conclude that testing algorithms taking advantage of inter-eye spatial concordance would not be particularly advantageous in the early detection of glaucomatous deterioration.
Aged ; Female ; Glaucoma, Open-Angle/diagnosis/*epidemiology/physiopathology ; Humans ; Male ; Middle Aged ; Prevalence ; Space Perception/*physiology ; Vision Disorders/diagnosis/*epidemiology/physiopathology ; Visual Field Tests ; Visual Fields/*physiology

Amyloid beta-Peptides ; analysis ; Animals ; Frontal Lobe ; drug effects ; physiology ; Hippocampus ; drug effects ; physiology ; Learning ; drug effects ; Memory ; drug effects ; Rats ; Rats, Wistar ; Sodium Azide ; pharmacology ; Space Perception

BACKGROUNDThere has been a long debate among scholars surrounding the relationship between language and cognition. The worldwide study of aphasia is actively exploring the function of language from cognitive point of view. This study aimed to investigate the relationship between linguistic functions and cognitive functions in a clinical study of Chinese patients with post-stroke aphasia.

METHODSCognitive functions of 63 Chinese patients with aphasia following a stroke were assessed with the Chinese version of the second edition of Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) battery and their linguistic functions were tested with the Western Aphasia Battery (WAB) Scale, respectively. The correlation between the results observed on the LOTCA battery and those on the WAB was analyzed. Aphasia quotient, performance quotient, cortical quotient, and linguistic function of the patients were compared. Then, each language function was analyzed by way of dependent adopt multiple regression analysis.

RESULTSThe total score of 63 patients as shown on the LOTCA battery was significantly correlated with the aphasia quotient, performance quotient, and cortical quotient observed on the WAB Scale (P < 0.05, P < 0.01). However, the correlation between visuomotor organization under LOTCA and repeat under WAB was not significant (P > 0.05). The attention of LOTCA and WAB's spontaneous speech, repeat, naming, and aphasia quotient was not relevant either (P > 0.05). In addition, correlations between the results observed on the LOTCA battery and the WAB were significant (P < 0.05, P < 0.01). Among the significant variables finally entered into the standardized canonical discriminant functions, main factors affected the aphasia. Multiple regression analysis showed that orientation, spatial perception, and visual perception had a notable influence on aphasia quotient and naming. Orientation and thinking operation was found to have a notable influence on spontaneous speech. Spatial perception and visual perception was found to have a notable influence on auditory comprehension. Thinking operation and orientation was found to have an obvious influence on reading. Thinking operation, spatial perception, and attention was found to have a notable effect on writing (P < 0.01).

CONCLUSIONThere exists a close relationship between linguistic functions and cognitive orientation, spatial perception, visual perception, and thinking operation in a clinical study of Chinese patients with post-stroke aphasia.

Adult ; Aged ; Aged, 80 and over ; Aphasia ; physiopathology ; Asian Continental Ancestry Group ; Cognition ; physiology ; Female ; Humans ; Language ; Male ; Middle Aged ; Space Perception ; physiology ; Young Adult

In this paper, the spatial spectra of neural electric activities and their primary application to visual spatial selective attention are presented. Based on the spherical harmonic spectra inversion by equivalent distributed dipole layer technique, novel latitude spectra S(1) and longitudinal spectra S(m) are defined as the description of spatial spectra of brain electric activities. When the latitude and longitudinal spectra are applied to the event-related potentials (ERP) of spatial selective attention to the right and left visual fields, the temporal structures of spatial spectra of all temporal sample points show meaningful delay and amplitude differences of components between 100 ms and 200 ms for attended and unattended stimulus conditions. These facts indicate that the latitude and longitudinal spatial spectra concept is useful in study of cognitive brain research.
Attention ; physiology ; Brain ; physiology ; Brain Mapping ; Electroencephalography ; Event-Related Potentials, P300 ; physiology ; Evoked Potentials, Visual ; physiology ; Models, Neurological ; Pattern Recognition, Visual ; physiology ; Photic Stimulation ; Space Perception ; Spatial Behavior ; physiology

OBJECTIVETo investigate the effect of GEPT extracts on spatial learning ability of the APPV717I transgenic mice at the early stage of dementia and its possible mechanism.

METHODThirty APPV717I transgenic mice were randomly divided into three GEPT groups by intragastric administration at doses of 0.075, 0.15, 0.3 g x kg(-1) x d(-1), and a donepezil group by intragastric administration of 0.92 mg x kg(-1) x d(-1), a APPV717I transgenic model group and a normal group by intragastric administration of distilled water. A four-month treatment regimen with GEPT extracts was administered to APPV717I transgenic mice. Results showed that Spatial memory ability was measured in Morris water maze. The total area covered by shank1 and integral optical density in CA1 subfield within the hippocampus were determined using immunohistochemical stains and Image-Pro plus analysis. The ultrastructure of synapses in the hippocampal CA1 region was observed by electronic microscope.

RESULTAfter a four-month of GEPT treatment regimen, the mean escape latency period were significantly shortened (P < 0.05), and the target quadrant search time were significantly increased (P < 0.05) compared to the APPV717I transgenic model mice. There was a significant higher level in the expression of shank1 detected in the hippocampal CA1 area of APPV717I transgenic mice associated with an increase in the number of synapses treated with GEPT than the levels in the APPV717I transgenic model mice alone. The total area of positive cells covered by shank1 and their integral optical density in the hippocampal CA1 area of the APPV717I transgenic mice treated with GEPT were significantly increased more than those of the APPV717I transgenic model mice.

CONCLUSIONGEPT extracts can obviously improve the spatial memory ability of APPV717I transgenic mice at the early stage of dementia through enhancing the number of synapses and the expression of shank1, and this might lead to development of novel treatment therapies for the memory loss associated with AD.

Animals ; Dementia ; prevention & control ; Disease Models, Animal ; Female ; Learning ; Male ; Memory ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mice, Transgenic ; Panax ; chemistry ; Plant Extracts ; therapeutic use ; Space Perception ; drug effects ; physiology ; Spatial Behavior ; drug effects ; physiology