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The effect of retrosplenial cortex lesions in rats on incidental and active spatial learning.

Nelson AJ, Hindley EL, Pearce JM, Vann SD, Aggleton JP - Front Behav Neurosci (2015)

Bottom Line: The study examined the importance of the retrosplenial cortex for the incidental learning of the spatial arrangement of distinctive features within a scene.In a modified Morris water-maze, rats spontaneously learnt the location of an escape platform prior to swimming to that location.A reduced preference for the correct corner was also found in Experiment 2, when platform location was determined by the juxtaposition of highly salient visual cues (black vs. white walls).

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, Cardiff University Cardiff, UK.

ABSTRACT
The study examined the importance of the retrosplenial cortex for the incidental learning of the spatial arrangement of distinctive features within a scene. In a modified Morris water-maze, rats spontaneously learnt the location of an escape platform prior to swimming to that location. For this, rats were repeatedly placed on a submerged platform in one corner of either a rectangular (Experiment 1) or square (Experiments 2, 3) pool with walls of different appearance. The rats were then released in the center of the pool for their first test trial. In Experiment 1, the correct corner and its diagonally opposite partner (also correct) were specified by the geometric properties of the pool. Rats with retrosplenial lesions took longer to first reach a correct corner, subsequently showing an attenuated preference for the correct corners. A reduced preference for the correct corner was also found in Experiment 2, when platform location was determined by the juxtaposition of highly salient visual cues (black vs. white walls). In Experiment 3, less salient visual cues (striped vs. white walls) led to a robust lesion impairment, as the retrosplenial lesioned rats showed no preference for the correct corner. When subsequently trained actively to swim to the correct corner over successive trials, retrosplenial lesions spared performance on all three discriminations. The findings not only reveal the importance of the retrosplenial cortex for processing various classes of visuospatial information but also highlight a broader role in the incidental learning of the features of a spatial array, consistent with the translation of scene information.

No MeSH data available.


Experiment 1—Incidental placement training in the rectangular pool. Probe performance is measured as the mean percentage time (±S.E.M) spent swimming in either the correct or incorrect (mirror-image) corners for both the Sham1 and RSC1 groups during the Probe Tests in the rectangle (left-hand) and kite (right hand). * denotes significant difference between the groups, t-test p < 0.05.
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Figure 3: Experiment 1—Incidental placement training in the rectangular pool. Probe performance is measured as the mean percentage time (±S.E.M) spent swimming in either the correct or incorrect (mirror-image) corners for both the Sham1 and RSC1 groups during the Probe Tests in the rectangle (left-hand) and kite (right hand). * denotes significant difference between the groups, t-test p < 0.05.

Mentions: Initial analysis revealed that there were no differences between the two groups in swimming speeds on either probe (both Fs < 1). The RSC1 group took longer to first reach the correct corner(s) in the first probe (rectangular pool) relative to the Sham1 group (F(1,22) = 5.9, p < 0.05) [mean latency s (±S.E.M): RSC1 = 17.3 (±2.0); Sham1 = 10.7 (±1.7)]. For the second probe (kite pool) the latency to first reach the correct corner did not differ by lesion group (F < 1) [mean latency s (±S.E.M): RSC1 = 20.8 (±3.9); Sham1 = 15.7 (±4.0)]. In the rectangle (t(22) = 2.3, p < 0.05) but not the kite (t(22) = < 1), sham animals spent longer in the correct corner(s) than the RSC1 animals (Figure 3). Time spent in the incorrect corner did not differ by lesion group in the rectangle (t < 1), but in the kite there was a trend towards the RSC1 group spending more time in the incorrect corner relative to the Sham1 group (t(22) = 1.9, p = 0.059).


The effect of retrosplenial cortex lesions in rats on incidental and active spatial learning.

Nelson AJ, Hindley EL, Pearce JM, Vann SD, Aggleton JP - Front Behav Neurosci (2015)

Experiment 1—Incidental placement training in the rectangular pool. Probe performance is measured as the mean percentage time (±S.E.M) spent swimming in either the correct or incorrect (mirror-image) corners for both the Sham1 and RSC1 groups during the Probe Tests in the rectangle (left-hand) and kite (right hand). * denotes significant difference between the groups, t-test p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4319482&req=5

Figure 3: Experiment 1—Incidental placement training in the rectangular pool. Probe performance is measured as the mean percentage time (±S.E.M) spent swimming in either the correct or incorrect (mirror-image) corners for both the Sham1 and RSC1 groups during the Probe Tests in the rectangle (left-hand) and kite (right hand). * denotes significant difference between the groups, t-test p < 0.05.
Mentions: Initial analysis revealed that there were no differences between the two groups in swimming speeds on either probe (both Fs < 1). The RSC1 group took longer to first reach the correct corner(s) in the first probe (rectangular pool) relative to the Sham1 group (F(1,22) = 5.9, p < 0.05) [mean latency s (±S.E.M): RSC1 = 17.3 (±2.0); Sham1 = 10.7 (±1.7)]. For the second probe (kite pool) the latency to first reach the correct corner did not differ by lesion group (F < 1) [mean latency s (±S.E.M): RSC1 = 20.8 (±3.9); Sham1 = 15.7 (±4.0)]. In the rectangle (t(22) = 2.3, p < 0.05) but not the kite (t(22) = < 1), sham animals spent longer in the correct corner(s) than the RSC1 animals (Figure 3). Time spent in the incorrect corner did not differ by lesion group in the rectangle (t < 1), but in the kite there was a trend towards the RSC1 group spending more time in the incorrect corner relative to the Sham1 group (t(22) = 1.9, p = 0.059).

Bottom Line: The study examined the importance of the retrosplenial cortex for the incidental learning of the spatial arrangement of distinctive features within a scene.In a modified Morris water-maze, rats spontaneously learnt the location of an escape platform prior to swimming to that location.A reduced preference for the correct corner was also found in Experiment 2, when platform location was determined by the juxtaposition of highly salient visual cues (black vs. white walls).

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, Cardiff University Cardiff, UK.

ABSTRACT
The study examined the importance of the retrosplenial cortex for the incidental learning of the spatial arrangement of distinctive features within a scene. In a modified Morris water-maze, rats spontaneously learnt the location of an escape platform prior to swimming to that location. For this, rats were repeatedly placed on a submerged platform in one corner of either a rectangular (Experiment 1) or square (Experiments 2, 3) pool with walls of different appearance. The rats were then released in the center of the pool for their first test trial. In Experiment 1, the correct corner and its diagonally opposite partner (also correct) were specified by the geometric properties of the pool. Rats with retrosplenial lesions took longer to first reach a correct corner, subsequently showing an attenuated preference for the correct corners. A reduced preference for the correct corner was also found in Experiment 2, when platform location was determined by the juxtaposition of highly salient visual cues (black vs. white walls). In Experiment 3, less salient visual cues (striped vs. white walls) led to a robust lesion impairment, as the retrosplenial lesioned rats showed no preference for the correct corner. When subsequently trained actively to swim to the correct corner over successive trials, retrosplenial lesions spared performance on all three discriminations. The findings not only reveal the importance of the retrosplenial cortex for processing various classes of visuospatial information but also highlight a broader role in the incidental learning of the features of a spatial array, consistent with the translation of scene information.

No MeSH data available.