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Environmental enrichment does not influence hypersynchronous network activity in the Tg2576 mouse model of Alzheimer's disease.

Bezzina C, Verret L, Halley H, Dahan L, Rampon C - Front Aging Neurosci (2015)

Bottom Line: The cognitive reserve hypothesis claims that the brain can overcome pathology by reinforcing preexistent processes or by developing alternative cognitive strategies.Epidemiological studies have revealed that this reserve can be built throughout life experiences as education or leisure activities.As aberrant oscillatory activity can contribute to memory deficits, we wondered whether the long-lasting memory improvements observed after EE were associated with a reduction of neuronal network hypersynchrony.

View Article: PubMed Central - PubMed

Affiliation: UMR5169 CNRS, Centre de Recherches sur la Cognition Animale, Université de Toulouse, Université Paul Sabatier Toulouse, France ; CNRS, Centre de Recherches sur la Cognition Animale Toulouse, France.

ABSTRACT
The cognitive reserve hypothesis claims that the brain can overcome pathology by reinforcing preexistent processes or by developing alternative cognitive strategies. Epidemiological studies have revealed that this reserve can be built throughout life experiences as education or leisure activities. We previously showed that an early transient environmental enrichment (EE) durably improves memory performances in the Tg2576 mouse model of Alzheimer's disease (AD). Recently, we evidenced a hypersynchronous brain network activity in young adult Tg2576 mice. As aberrant oscillatory activity can contribute to memory deficits, we wondered whether the long-lasting memory improvements observed after EE were associated with a reduction of neuronal network hypersynchrony. Thus, we exposed non-transgenic (NTg) and Tg2576 mice to standard or enriched housing conditions for 10 weeks, starting at 3 months of age. Two weeks after EE period, Tg2576 mice presented similar seizure susceptibility to a GABA receptor antagonist. Immediately after and 2 weeks after this enrichment period, standard and enriched-housed Tg2576 mice did not differ with regards to the frequency of interictal spikes on their electroencephalographic (EEG) recordings. Thus, the long-lasting effect of this EE protocol on memory capacities in Tg2576 mice is not mediated by a reduction of their cerebral aberrant neuronal activity at early ages.

No MeSH data available.


Related in: MedlinePlus

Environmental enrichment does not modify the susceptibility to PTZ-induced seizures in Tg2576 females. Seizure severity score of 6 month-old Tg2576 and non-transgenic (NTg) females, housed under standard (SH) or enriched conditions (EE). Whiskers boxes represent the interquartile distribution. Kruskal-Wallis test reveals a significant global effect (p = 0.0012). ns: p = 0.05; *p < 0.05 for Dunn’s post hoc tests.
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Figure 3: Environmental enrichment does not modify the susceptibility to PTZ-induced seizures in Tg2576 females. Seizure severity score of 6 month-old Tg2576 and non-transgenic (NTg) females, housed under standard (SH) or enriched conditions (EE). Whiskers boxes represent the interquartile distribution. Kruskal-Wallis test reveals a significant global effect (p = 0.0012). ns: p = 0.05; *p < 0.05 for Dunn’s post hoc tests.

Mentions: Our aim was to determine whether EE has an effect on seizure susceptibility in Tg2576 mice. After the completion of EE, one or 2 days after the last EEG recording, we assessed seizure susceptibility to the GABAA receptor antagonist PTZ in NTg and Tg2576 mice housed in standard or enriched conditions. Tg2576 females exhibited more severe seizures than NTg females (Figure 3; Kruskal-Wallis: p = 0.0012, Dunn’s post hoc tests: p < 0.05 for NTg EE vs Tg2576 EE and for NTg SH vs Tg2576 SH). However, our data indicate that seizure severity did not differ between Tg2576 mice housed under standard and enriched conditions (Dunn’s post hoc test: p > 0.05 for Tg2576 SH vs Tg2576 EE). In summary, EE does not durably modify seizure susceptibility to PTZ in Tg2576 females.


Environmental enrichment does not influence hypersynchronous network activity in the Tg2576 mouse model of Alzheimer's disease.

Bezzina C, Verret L, Halley H, Dahan L, Rampon C - Front Aging Neurosci (2015)

Environmental enrichment does not modify the susceptibility to PTZ-induced seizures in Tg2576 females. Seizure severity score of 6 month-old Tg2576 and non-transgenic (NTg) females, housed under standard (SH) or enriched conditions (EE). Whiskers boxes represent the interquartile distribution. Kruskal-Wallis test reveals a significant global effect (p = 0.0012). ns: p = 0.05; *p < 0.05 for Dunn’s post hoc tests.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4585132&req=5

Figure 3: Environmental enrichment does not modify the susceptibility to PTZ-induced seizures in Tg2576 females. Seizure severity score of 6 month-old Tg2576 and non-transgenic (NTg) females, housed under standard (SH) or enriched conditions (EE). Whiskers boxes represent the interquartile distribution. Kruskal-Wallis test reveals a significant global effect (p = 0.0012). ns: p = 0.05; *p < 0.05 for Dunn’s post hoc tests.
Mentions: Our aim was to determine whether EE has an effect on seizure susceptibility in Tg2576 mice. After the completion of EE, one or 2 days after the last EEG recording, we assessed seizure susceptibility to the GABAA receptor antagonist PTZ in NTg and Tg2576 mice housed in standard or enriched conditions. Tg2576 females exhibited more severe seizures than NTg females (Figure 3; Kruskal-Wallis: p = 0.0012, Dunn’s post hoc tests: p < 0.05 for NTg EE vs Tg2576 EE and for NTg SH vs Tg2576 SH). However, our data indicate that seizure severity did not differ between Tg2576 mice housed under standard and enriched conditions (Dunn’s post hoc test: p > 0.05 for Tg2576 SH vs Tg2576 EE). In summary, EE does not durably modify seizure susceptibility to PTZ in Tg2576 females.

Bottom Line: The cognitive reserve hypothesis claims that the brain can overcome pathology by reinforcing preexistent processes or by developing alternative cognitive strategies.Epidemiological studies have revealed that this reserve can be built throughout life experiences as education or leisure activities.As aberrant oscillatory activity can contribute to memory deficits, we wondered whether the long-lasting memory improvements observed after EE were associated with a reduction of neuronal network hypersynchrony.

View Article: PubMed Central - PubMed

Affiliation: UMR5169 CNRS, Centre de Recherches sur la Cognition Animale, Université de Toulouse, Université Paul Sabatier Toulouse, France ; CNRS, Centre de Recherches sur la Cognition Animale Toulouse, France.

ABSTRACT
The cognitive reserve hypothesis claims that the brain can overcome pathology by reinforcing preexistent processes or by developing alternative cognitive strategies. Epidemiological studies have revealed that this reserve can be built throughout life experiences as education or leisure activities. We previously showed that an early transient environmental enrichment (EE) durably improves memory performances in the Tg2576 mouse model of Alzheimer's disease (AD). Recently, we evidenced a hypersynchronous brain network activity in young adult Tg2576 mice. As aberrant oscillatory activity can contribute to memory deficits, we wondered whether the long-lasting memory improvements observed after EE were associated with a reduction of neuronal network hypersynchrony. Thus, we exposed non-transgenic (NTg) and Tg2576 mice to standard or enriched housing conditions for 10 weeks, starting at 3 months of age. Two weeks after EE period, Tg2576 mice presented similar seizure susceptibility to a GABA receptor antagonist. Immediately after and 2 weeks after this enrichment period, standard and enriched-housed Tg2576 mice did not differ with regards to the frequency of interictal spikes on their electroencephalographic (EEG) recordings. Thus, the long-lasting effect of this EE protocol on memory capacities in Tg2576 mice is not mediated by a reduction of their cerebral aberrant neuronal activity at early ages.

No MeSH data available.


Related in: MedlinePlus