Chronic stress impairs rat spatial memory on the Y maze, and this effect is blocked by tianeptine treatment.

To investigate whether HT008-1, a prescription used in traditional Korean medicine to treat mental and physical weakness, has a neuroprotective effect on a rat model of global brain ischemia and an enhancing effect against memory deficit following ischemia. Global brain ischemia was induced for 10 min by using 4-vessel occlusion (4-VO). HT008-1 was orally administered at doses of 30, 100, and 300 mg/kg respectively twice at 0 and 90 min after ischemia. The effect on memory deficit was investigated by using a Y-maze neurobehavioral test 4 days after brain ischemia, and the effect on neuronal damage was measured 7 days after ischemia. The mechanism of action was studied immunohistochemically using an anti-CD11b (OX-42) antibody. The oral administration of HT008-1 at 100 and 300 mg/kg significantly reduced hippocampal neuronal cell death by 49% and 53%, respectively, compared with a vehicle-treated group, and also improved spatial memory function in the Y-maze test. Immunohistochemically, HT008-1 inhibited OX-42 expression in the hippocampus. The effects of HT008-1 were more pronounced than those of its individual herb components. The herbal mixture HT008-1 protects the most vulnerable CA1 pyramidal cells of the hippocampus and enhances spatial memory function against global brain ischemia; an anti-inflammatory effect may be one of the mechanisms of action.

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Subchronic Oral Bromocriptine Methanesulfonate Enhances Open Field Novelty-Induced Behavior and Spatial Memory in Male Swiss Albino Mice

Neuroscience Journal ◽

10.1155/2013/948241 ◽

2013 ◽

Vol 2013 ◽

pp. 1-5

Author(s):

Olakunle James Onaolapo ◽

Adejoke Yetunde Onaolapo

Keyword(s):

Spatial Memory ◽

Open Field ◽

Cumulative Effect ◽

Male Mice ◽

Healthy Male ◽

Swiss Albino Mice ◽

Y Maze ◽

Field Assessment ◽

Albino Mice ◽

Neurobehavioral Effects

This study set out to assess the neurobehavioral effects of subchronic, oral bromocriptine methanesulfonate using the open field and the Y-maze in healthy male mice. Sixty adult Swiss albino mice were assigned into three groups. Controls received normal saline, while test groups received bromocriptine methanesulfonate at 2.5 and 5 mg/kg/day, respectively, for a period of 21 days. Neurobehavioral tests were carried out on days 1 and 21 after administration. Open field assessment on day 1 after administration revealed significant increase in grooming at 2.5 and 5 mg/kg, while horizontal and vertical locomotion showed no significant changes. Day 1 also showed no significant changes in Y-maze alternation. On day 21, horizontal locomotion, rearing, and grooming were increased significantly at 2.5 and 5 mg/kg doses after administration; also, spatial memory was significantly enhanced at 2.5 mg/kg. In conclusion, the study demonstrates the ability of oral bromocriptine to affect neurobehavior in normal mice. It also suggests that there is a cumulative effect of oral bromocriptine on the behaviors studied with more changes being seen after subchronic administration rather than after a single oral dose.

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Chronic social stress-induced hyperglycemia in mice couples individual stress susceptibility to impaired spatial memory

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1804412115 ◽

2018 ◽

Vol 115 (43) ◽

pp. E10187-E10196 ◽

Cited By ~ 19

Author(s):

Michael A. van der Kooij ◽

Tanja Jene ◽

Giulia Treccani ◽

Isabelle Miederer ◽

Annika Hasch ◽

...

Keyword(s):

Glucose Metabolism ◽

Spatial Memory ◽

Chronic Stress ◽

High Glucose ◽

Social Stress ◽

Cognitive Impairments ◽

Memory Performance ◽

Dietary Treatment ◽

Metabolic Phenotype ◽

The Brain

Stringent glucose demands render the brain susceptible to disturbances in the supply of this main source of energy, and chronic stress may constitute such a disruption. However, whether stress-associated cognitive impairments may arise from disturbed glucose regulation remains unclear. Here we show that chronic social defeat (CSD) stress in adult male mice induces hyperglycemia and directly affects spatial memory performance. Stressed mice developed hyperglycemia and impaired glucose metabolism peripherally as well as in the brain (demonstrated by PET and induced metabolic bioluminescence imaging), which was accompanied by hippocampus-related spatial memory impairments. Importantly, the cognitive and metabolic phenotype pertained to a subset of stressed mice and could be linked to early hyperglycemia 2 days post-CSD. Based on this criterion, ∼40% of the stressed mice had a high-glucose (glucose >150 mg/dL), stress-susceptible phenotype. The relevance of this biomarker emerges from the effects of the glucose-lowering sodium glucose cotransporter 2 inhibitor empagliflozin, because upon dietary treatment, mice identified as having high glucose demonstrated restored spatial memory and normalized glucose metabolism. Conversely, reducing glucose levels by empagliflozin in mice that did not display stress-induced hyperglycemia (resilient mice) impaired their default-intact spatial memory performance. We conclude that hyperglycemia developing early after chronic stress threatens long-term glucose homeostasis and causes spatial memory dysfunction. Our findings may explain the comorbidity between stress-related and metabolic disorders, such as depression and diabetes, and suggest that cognitive impairments in both types of disorders could originate from excessive cerebral glucose accumulation.

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Elimination of Vesicular Zinc Alters the Behavioural and Neuroanatomical Effects of Social Defeat Stress in Mice

10.1101/402891 ◽

2018 ◽

Author(s):

Brendan B. McAllister ◽

David K. Wright ◽

Ryan C. Wortman ◽

Sandy R. Shultz ◽

Richard H. Dyck

Keyword(s):

Corpus Callosum ◽

Chronic Stress ◽

Social Defeat ◽

Volumetric Analysis ◽

Hippocampal Neurogenesis ◽

Wild Type ◽

Enhanced Sensitivity ◽

Y Maze ◽

Genetic Deletion ◽

Stress Susceptibility

ABSTRACTChronic stress can have deleterious effects on mental health, increasing the risk of developing depression or anxiety. But not all individuals are equally affected by stress; some are susceptible while others are more resilient. Understanding the mechanisms that lead to these differing outcomes has been a focus of considerable research. One unexplored mechanism is vesicular zinc – zinc that is released by neurons as a neuromodulator. We examined how chronic stress, induced by repeated social defeat, affects mice that lack vesicular zinc due to genetic deletion of zinc transporter 3 (ZnT3). These mice, unlike wild type mice, did not become socially avoidant of a novel conspecific, suggesting resilience to stress. However, they showed enhanced sensitivity to the potentiating effect of stress on cued fear memory. Thus, the contribution of vesicular zinc to stress susceptibility is not straightforward. Stress also increased anxiety-like behaviour but produced no deficits in a spatial Y-maze test. We found no evidence that microglial activation or hippocampal neurogenesis accounted for the differences in behavioural outcome. Volumetric analysis revealed that ZnT3 KO mice have larger corpus callosum and parietal cortex volumes, and that corpus callosum volume was decreased by stress in ZnT3 KO, but not wild type, mice.

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A Walnut-enriched Diet and Physical Activity Enhanced Cognitive and Motor Function in Aged Mice (P14-010-19)

Current Developments in Nutrition ◽

10.1093/cdn/nzz052.p14-010-19 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Author(s):

Carsten Esselun ◽

Benjamin Dilberger ◽

Carmina Silaidos ◽

Gunter Eckert

Keyword(s):

Physical Activity ◽

Spatial Memory ◽

Motor Function ◽

Mitochondrial Function ◽

Brain Aging ◽

Enriched Environment ◽

Motor Functions ◽

Nmri Mice ◽

Aged Mice ◽

Y Maze

Abstract Objectives This study aims to investigate walnut's effect alone and in combination with an enriched environment on brain aging of aged NMRI mice by investigation of cognition and motor functions. Furthermore, it aims to identify the underlying mechanisms by evaluating the expression of relevant genes. Methods NMRI mice (12mo.) were fed with a 6% walnut-enriched diet (WED) or control diet respectively, for the duration of 6 months. Additionally, one WED group was exposed to an enriched environment. Cognition and motor functions were assessed to evaluate walnut's effect on spatial memory, general physical activity and motor coordination. Conducted tests included Y-Maze alternation, open field and rotarod. Expression levels of relevant genes including synaptophysin, NGF and BDNF were measured via qPCR in brain tissue. Mitochondrial function was investigated by testing for ATP levels and mitochondrial membrane potential in dissociated brain cells and oxygen consumption of the oxidative phosphorylation system of freshly isolated mitochondria. Results Intake of the walnut diet significantly increased the alternation rate in a Y-Maze experiment (P < 0.05). Physical activity did not further improve this effect on spatial memory of mice, but increased mice’ activity (P < 0.001) in general. Motor function in rotarod test was not improved by walnut intake alone, but significantly increased by added enrichment (P < 0.01). Gene expression of synaptophysin was significantly increased for walnuts alone (P < 0.05), while BDNF and NGF expression appeared to be unaffected. Additional enriched environment resulted in a trend for these genes to be increased as well. Results imply that mitochondrial function is not linked to these improvements. Conclusions Long term walnut diet significantly improved cognitive function in aged mice. Physical activity additionally improved motor functions. These benefits could possibly be explained by increased expression of genes involved in neuronal plasticity. Funding Sources Grant from California Walnut Commission.

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Chronic stress impairs spatial memory and motivation for reward without disrupting motor ability and motivation to explore.

Behavioral Neuroscience ◽

10.1037/0735-7044.120.4.842 ◽

2006 ◽

Vol 120 (4) ◽

pp. 842-851 ◽

Cited By ~ 97

Author(s):

Jonathan K. Kleen ◽

Matthew T. Sitomer ◽

Peter R. Killeen ◽

Cheryl D. Conrad

Keyword(s):

Spatial Memory ◽

Chronic Stress ◽

Motor Ability

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BDNF and TrkB Mediate the Improvement from Chronic Stress-induced Spatial Memory Deficits and CA3 Dendritic Retraction

Neuroscience ◽

10.1016/j.neuroscience.2018.07.049 ◽

2018 ◽

Vol 388 ◽

pp. 330-346 ◽

Cited By ~ 8

Author(s):

J. Bryce Ortiz ◽

Julia M. Anglin ◽

Eshaan J. Daas ◽

Pooja R. Paode ◽

Kenji Nishimura ◽

...

Keyword(s):

Spatial Memory ◽

Chronic Stress ◽

Memory Deficits

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Chronic stress enhances spatial memory in ovariectomized female rats despite CA3 dendritic retraction: Possible involvement of CA1 neurons

Neuroscience ◽

10.1016/j.neuroscience.2005.06.083 ◽

2005 ◽

Vol 135 (4) ◽

pp. 1045-1054 ◽

Cited By ~ 83

Author(s):

K.J. McLaughlin ◽

S.E. Baran ◽

R.L. Wright ◽

C.D. Conrad

Keyword(s):

Spatial Memory ◽

Chronic Stress ◽

Female Rats ◽

Ca1 Neurons

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Training level reveals a dynamic dialogue between stress and memory systems in birds

10.1101/2021.01.05.425468 ◽

2021 ◽

Author(s):

Flore Lormant ◽

Vitor Hugo Bessa Ferreira ◽

Julie Lemarchand ◽

Fabien Cornilleau ◽

Paul Constantin ◽

...

Keyword(s):

Spatial Memory ◽

Chronic Stress ◽

Memory Systems ◽

Psychological State ◽

Training Level ◽

Initial Training ◽

Emotional Challenge ◽

Test Occasion ◽

The Individual ◽

And Training

AbstractIt is now well-accepted that memory is a dynamic process, and that stress and training level may influence which memory system an individual engages when solving a task. In this work, we investigated whether and how chronic stress impacts spatial and cue-based memories according to training level. To that aim, control and chronically stressed Japanese quail were trained in a task that could be solved using spatial and cue-based memory and tested for their memory performances after 5 and 15 training days (initial training and overtraining, respectively) and following an emotional challenge (exposure to an open field). While chronic stress negatively impacted spatial memory in chronically stressed birds after initial training, this impact was lowered after overtraining compared to control quail. Interestingly, the emotional challenge reinstated the differences in performance between the two groups, revealing that chronic stress/overtraining did not eliminate spatial memory. Differences caused by previous stressors can re-emerge depending on the more immediate psychological state of the individual. Contrary to spatial memory, cue-based memory was not impaired in any test occasion, confirming that this form of memory is resistant to chronic stress. Altogether these findings reveal a dynamic dialogue between stress, training, and memory systems in birds.

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