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Spatial Navigation Task (spatial + navigation_task)
Selected AbstractsTherapeutic effects of complex rearing or bFGF after perinatal frontal lesionsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 2 2008Wendy Comeau Abstract We investigated the effects of an enriched environment and/or basic fibroblast growth factor (bFGF) on recovery from neonatal frontal injury in rats. Rats received medial frontal lesions, or sham surgery, on postnatal day (P) 2/3. In the first set of experiments (Experiments 1 and 2), rats were housed in enriched environments that consisted of a large enclosure with multiple objects (or standard housing) for 90 days beginning at weaning (P22) or in adulthood (P110). In Experiment 3, the rats either received 7 days of subcutaneous bFGF beginning on the day after surgery or bFGF plus enriched housing beginning at weaning. After the 90-day housing period, the animals were tested on a spatial navigation task and a skilled reaching task. Early lesions of the medial frontal cortex caused severe impairments in spatial learning but this deficit was markedly reduced with enriched housing, bFGF, or a combination of both, with the latter being most effective. The housing effects varied with age, however: the earlier the experience began, the better the outcome. Enriched housing increased dendritic length in cortical pyramidal neurons, an effect that was greater in the lesion than the control animals, and enriched housing reversed the lesion-induced decrease in spine density. Enriched environment increased the thickness of the cortical mantle in both lesion and controls whereas bFGF had no effect. Experience thus can affect functional and anatomical outcome after early brain injury but the effects vary with age at experience and may be facilitated by treatment with bFGF. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 134,146, 2008. [source] Does the cingulate cortex contribute to spatial conditional associative learning in the rat?HIPPOCAMPUS, Issue 7 2009Marie St-Laurent Abstract Rats with lesions to the anterior or posterior (retrosplenial) region of the cingulate cortex and rats with lesions that included both the anterior and posterior cingulate cortex were tested on a visual,spatial conditional task in which they had to learn to approach one of the two objects depending on the spatial context within which they were embedded. Lesions restricted to either the anterior or the retrosplenial cingulate region did not impair learning of this task which is known to be very sensitive to the effects of hippocampal lesions. Complete lesions of the cingulate cortex gave rise to only a minor retardation in learning. In contrast, lesions to the retrosplenial cortex impaired performance on a spatial navigation task and the classic radial maze. These results suggest that the retrosplenial portion of the cingulate region forms part of a hippocampal circuit underlying learning about spatial responses. The dissociation between the effects of lesions of the cingulate region on different classes of behavior known to be associated with hippocampal function suggests that, although this neural structure does play a role in an extended hippocampal circuit underlying spatial learning, its role in such learning may be a selective one. © 2009 Wiley-Liss, Inc. [source] Spatial firing properties of lateral septal neuronsHIPPOCAMPUS, Issue 8 2006Yusaku Takamura Abstract The present study describes the spatial firing properties of neurons in the lateral septum (LS). LS neuronal activity was recorded in rats as they performed a spatial navigation task in an open field. In this task, the rat acquired an intracranial self-stimulation reward when it entered a certain place, a location that varied randomly from trial to trial. Of 193 neurons recorded in the LS, 81 showed place-related activity. The majority of the tested neurons changed place-related activity when spatial relations between environmental cues were altered by rotating intrafield (proximal) cues. The comparison of place activities between LS place-related neurons recorded in the present study and hippocampal place cells recorded in our previous study, using identical behavioral and recording procedures, revealed that spatial parameters (spatial information content, coherence, and cluster size) were smaller in the LS than in the hippocampus. Of the 193 LS neurons, 86 were influenced by intracranial self-stimulation rewards; 31 of these 86 were also place-related. These results, together with previous anatomical and behavioral observations, suggest that the spatial information sent from the hippocampus to the LS is modulated by and interacts with signals related to reward in the LS. © 2006 Wiley-Liss, Inc. [source] Mobile phone exposure and spatial memoryBIOELECTROMAGNETICS, Issue 1 2009Clairy Wiholm Abstract Radiofrequency (RF) emission during mobile phone use has been suggested to impair cognitive functions, that is, working memory. This study investigated the effects of a 2,1/2 h RF exposure (884 MHz) on spatial memory and learning, using a double-blind repeated measures design. The exposure was designed to mimic that experienced during a real-life mobile phone conversation. The design maximized the exposure to the left hemisphere. The average exposure was peak spatial specific absorption rate (psSAR10g) of 1.4 W/kg. The primary outcome measure was a "virtual" spatial navigation task modeled after the commonly used and validated Morris Water Maze. The distance traveled on each trial and the amount of improvement across trials (i.e., learning) were used as dependent variables. The participants were daily mobile phone users, with and without symptoms attributed to regular mobile phone use. Results revealed a main effect of RF exposure and a significant RF exposure by group effect on distance traveled during the trials. The symptomatic group improved their performance during RF exposure while there was no such effect in the non-symptomatic group. Until this new finding is further investigated, we can only speculate about the cause. Bioelectromagnetics 30:59,65, 2009. © 2008 Wiley-Liss, Inc. [source] | ||||||||||