Limits...
Hippocampal Synaptic Expansion Induced by Spatial Experience in Rats Correlates with Improved Information Processing in the Hippocampus.

Carasatorre M, Ochoa-Alvarez A, Velázquez-Campos G, Lozano-Flores C, Ramírez-Amaya V, Díaz-Cintra SY - PLoS ONE (2015)

Bottom Line: The "catFISH" imaging method provided neurophysiological evidence that hippocampal pattern separation improved in animals treated as SC, and this improvement was even clearer in animals that experienced the WM training.By measuring the area occupied by synaptophysin staining in both the stratum oriens and the stratun lucidum of the distal CA3, we found evidence of structural synaptic plasticity that likely includes MF expansion.Finally, the measures of hippocampal network coding obtained with catFISH correlate significantly with the increased density of synaptophysin staining, strongly suggesting that structural synaptic plasticity in the hippocampus induced by the WM and SC experience is related to the improvement of spatial information processing in the hippocampus.

View Article: PubMed Central - PubMed

Affiliation: Department of "Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología", Universidad Nacional Autónoma de México, Querétaro, México.

ABSTRACT
Spatial water maze (WM) overtraining induces hippocampal mossy fiber (MF) expansion, and it has been suggested that spatial pattern separation depends on the MF pathway. We hypothesized that WM experience inducing MF expansion in rats would improve spatial pattern separation in the hippocampal network. We first tested this by using the the delayed non-matching to place task (DNMP), in animals that had been previously trained on the water maze (WM) and found that these animals, as well as animals treated as swim controls (SC), performed better than home cage control animals the DNMP task. The "catFISH" imaging method provided neurophysiological evidence that hippocampal pattern separation improved in animals treated as SC, and this improvement was even clearer in animals that experienced the WM training. Moreover, these behavioral treatments also enhance network reliability and improve partial pattern separation in CA1 and pattern completion in CA3. By measuring the area occupied by synaptophysin staining in both the stratum oriens and the stratun lucidum of the distal CA3, we found evidence of structural synaptic plasticity that likely includes MF expansion. Finally, the measures of hippocampal network coding obtained with catFISH correlate significantly with the increased density of synaptophysin staining, strongly suggesting that structural synaptic plasticity in the hippocampus induced by the WM and SC experience is related to the improvement of spatial information processing in the hippocampus.

No MeSH data available.


Related in: MedlinePlus

Spatial pattern separation in the DNMP task improves after water maze and swimming treatment.(A) Performance of animals during training in the Morris Water Maze task is expressed as the latency to reach the target platform; each point represents the average latency to reach the target from each pair of trials (5 pairs) from a total of 10 trials each animal underwent each daily session. The animals were trained during 5 sessions that occurred during 5 consecutive days. The trained animals showed a significant decrease in their latency to reach the target between trial pairs each day, particularly during the first 3 days (*** p<0.001, *p<0.05, repeated measures ANOVA). (B) The DNMP task consists of placing the animal in the middle of the start arm and then allowing it to find food at the end of the sample arm (SA), this occurs during the sample phase; during the next phase the animal is release in the same place but it now needs to find the choice arm (CA), which is the only place where food is now available and is open only in this choice phase. To solve the task the animal needs to distinguish the location of the newly available corridor from that one visited in the previous trial and the difficulty comes with the proximity of the 2 arms. (C) Four different separations between the SA and CA were tested (upper diagram); in Sp1 the SA and CA were adjacent to each other; in Sp2 one arm separates the SA and CA; in Sp3 two arms separate the SA and CA; and finally in Sp4, the SA and CA were opposite from each other; note that the start arm (in black) was 90° from either the SA or the CA (lower diagram), and the position of these baited arms alternated between left choice (LC) and right choice (RC) throughout trials. (D) The DNMP results are expressed as the average percentage of errors in all trials for each group (±SEM); note that WM and SC animals present significantly fewer errors than the IC group (***p<0.001, **p<0.01, *p<0.05) except in Sp4 were all groups perform well.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4526663&req=5

pone.0132676.g001: Spatial pattern separation in the DNMP task improves after water maze and swimming treatment.(A) Performance of animals during training in the Morris Water Maze task is expressed as the latency to reach the target platform; each point represents the average latency to reach the target from each pair of trials (5 pairs) from a total of 10 trials each animal underwent each daily session. The animals were trained during 5 sessions that occurred during 5 consecutive days. The trained animals showed a significant decrease in their latency to reach the target between trial pairs each day, particularly during the first 3 days (*** p<0.001, *p<0.05, repeated measures ANOVA). (B) The DNMP task consists of placing the animal in the middle of the start arm and then allowing it to find food at the end of the sample arm (SA), this occurs during the sample phase; during the next phase the animal is release in the same place but it now needs to find the choice arm (CA), which is the only place where food is now available and is open only in this choice phase. To solve the task the animal needs to distinguish the location of the newly available corridor from that one visited in the previous trial and the difficulty comes with the proximity of the 2 arms. (C) Four different separations between the SA and CA were tested (upper diagram); in Sp1 the SA and CA were adjacent to each other; in Sp2 one arm separates the SA and CA; in Sp3 two arms separate the SA and CA; and finally in Sp4, the SA and CA were opposite from each other; note that the start arm (in black) was 90° from either the SA or the CA (lower diagram), and the position of these baited arms alternated between left choice (LC) and right choice (RC) throughout trials. (D) The DNMP results are expressed as the average percentage of errors in all trials for each group (±SEM); note that WM and SC animals present significantly fewer errors than the IC group (***p<0.001, **p<0.01, *p<0.05) except in Sp4 were all groups perform well.

Mentions: In independent groups of rats we tested both a behavioral (DNMP) and a neurophysiological (catFISH) measure of spatial pattern separation. The DNMP task [21] revealed behavioural evidence of spatial pattern separation improvement after the animals experience both swimming exercise and particularly contextual learning (Fig 1).


Hippocampal Synaptic Expansion Induced by Spatial Experience in Rats Correlates with Improved Information Processing in the Hippocampus.

Carasatorre M, Ochoa-Alvarez A, Velázquez-Campos G, Lozano-Flores C, Ramírez-Amaya V, Díaz-Cintra SY - PLoS ONE (2015)

Spatial pattern separation in the DNMP task improves after water maze and swimming treatment.(A) Performance of animals during training in the Morris Water Maze task is expressed as the latency to reach the target platform; each point represents the average latency to reach the target from each pair of trials (5 pairs) from a total of 10 trials each animal underwent each daily session. The animals were trained during 5 sessions that occurred during 5 consecutive days. The trained animals showed a significant decrease in their latency to reach the target between trial pairs each day, particularly during the first 3 days (*** p<0.001, *p<0.05, repeated measures ANOVA). (B) The DNMP task consists of placing the animal in the middle of the start arm and then allowing it to find food at the end of the sample arm (SA), this occurs during the sample phase; during the next phase the animal is release in the same place but it now needs to find the choice arm (CA), which is the only place where food is now available and is open only in this choice phase. To solve the task the animal needs to distinguish the location of the newly available corridor from that one visited in the previous trial and the difficulty comes with the proximity of the 2 arms. (C) Four different separations between the SA and CA were tested (upper diagram); in Sp1 the SA and CA were adjacent to each other; in Sp2 one arm separates the SA and CA; in Sp3 two arms separate the SA and CA; and finally in Sp4, the SA and CA were opposite from each other; note that the start arm (in black) was 90° from either the SA or the CA (lower diagram), and the position of these baited arms alternated between left choice (LC) and right choice (RC) throughout trials. (D) The DNMP results are expressed as the average percentage of errors in all trials for each group (±SEM); note that WM and SC animals present significantly fewer errors than the IC group (***p<0.001, **p<0.01, *p<0.05) except in Sp4 were all groups perform well.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526663&req=5

pone.0132676.g001: Spatial pattern separation in the DNMP task improves after water maze and swimming treatment.(A) Performance of animals during training in the Morris Water Maze task is expressed as the latency to reach the target platform; each point represents the average latency to reach the target from each pair of trials (5 pairs) from a total of 10 trials each animal underwent each daily session. The animals were trained during 5 sessions that occurred during 5 consecutive days. The trained animals showed a significant decrease in their latency to reach the target between trial pairs each day, particularly during the first 3 days (*** p<0.001, *p<0.05, repeated measures ANOVA). (B) The DNMP task consists of placing the animal in the middle of the start arm and then allowing it to find food at the end of the sample arm (SA), this occurs during the sample phase; during the next phase the animal is release in the same place but it now needs to find the choice arm (CA), which is the only place where food is now available and is open only in this choice phase. To solve the task the animal needs to distinguish the location of the newly available corridor from that one visited in the previous trial and the difficulty comes with the proximity of the 2 arms. (C) Four different separations between the SA and CA were tested (upper diagram); in Sp1 the SA and CA were adjacent to each other; in Sp2 one arm separates the SA and CA; in Sp3 two arms separate the SA and CA; and finally in Sp4, the SA and CA were opposite from each other; note that the start arm (in black) was 90° from either the SA or the CA (lower diagram), and the position of these baited arms alternated between left choice (LC) and right choice (RC) throughout trials. (D) The DNMP results are expressed as the average percentage of errors in all trials for each group (±SEM); note that WM and SC animals present significantly fewer errors than the IC group (***p<0.001, **p<0.01, *p<0.05) except in Sp4 were all groups perform well.
Mentions: In independent groups of rats we tested both a behavioral (DNMP) and a neurophysiological (catFISH) measure of spatial pattern separation. The DNMP task [21] revealed behavioural evidence of spatial pattern separation improvement after the animals experience both swimming exercise and particularly contextual learning (Fig 1).

Bottom Line: The "catFISH" imaging method provided neurophysiological evidence that hippocampal pattern separation improved in animals treated as SC, and this improvement was even clearer in animals that experienced the WM training.By measuring the area occupied by synaptophysin staining in both the stratum oriens and the stratun lucidum of the distal CA3, we found evidence of structural synaptic plasticity that likely includes MF expansion.Finally, the measures of hippocampal network coding obtained with catFISH correlate significantly with the increased density of synaptophysin staining, strongly suggesting that structural synaptic plasticity in the hippocampus induced by the WM and SC experience is related to the improvement of spatial information processing in the hippocampus.

View Article: PubMed Central - PubMed

Affiliation: Department of "Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología", Universidad Nacional Autónoma de México, Querétaro, México.

ABSTRACT
Spatial water maze (WM) overtraining induces hippocampal mossy fiber (MF) expansion, and it has been suggested that spatial pattern separation depends on the MF pathway. We hypothesized that WM experience inducing MF expansion in rats would improve spatial pattern separation in the hippocampal network. We first tested this by using the the delayed non-matching to place task (DNMP), in animals that had been previously trained on the water maze (WM) and found that these animals, as well as animals treated as swim controls (SC), performed better than home cage control animals the DNMP task. The "catFISH" imaging method provided neurophysiological evidence that hippocampal pattern separation improved in animals treated as SC, and this improvement was even clearer in animals that experienced the WM training. Moreover, these behavioral treatments also enhance network reliability and improve partial pattern separation in CA1 and pattern completion in CA3. By measuring the area occupied by synaptophysin staining in both the stratum oriens and the stratun lucidum of the distal CA3, we found evidence of structural synaptic plasticity that likely includes MF expansion. Finally, the measures of hippocampal network coding obtained with catFISH correlate significantly with the increased density of synaptophysin staining, strongly suggesting that structural synaptic plasticity in the hippocampus induced by the WM and SC experience is related to the improvement of spatial information processing in the hippocampus.

No MeSH data available.


Related in: MedlinePlus