Progress 07/15/05 to 10/30/09
Outputs
Progress Report Objectives (from AD-416) Phase I. Assess the behavioral effects and blood levels of walnut fatty acids in the diets of the rats to determine the most effective supplementations of the walnuts in the diet to carry out experiments in Phase II of the proposal. Phase II. Aim-1 Determine the effects of walnuts (WL), blueberry (BB) or BB + WL supplementation on behavioral aging using paradigms sensitive to cognitive (short- and long-term memories) and motor behaviors. Aim 2: Determine the effects of these supplementations on calcium dependent neuronal signaling and neurogenesis (2b) and correlate these with alterations in behavioral parameters determined in A 1. Approach (from AD-416) The effects of BB dietary supplementation (2% BB extract in the diet), WL supplementation 2% WL extract in the diet) or WL + BB supplementation (1% each in the diet) will be examined on behavioral performance beginning 8 weeks after supplementation will have begun, in the rats using age-sensitive cognitive behaviors that are selective for reference and working memories. The effects of these supplementations on neurogenesis and differentiation will be examined using immunocytochemistry, bromodeoxyuridine) incorporation in hippocampus obtained from these animals. In addition we will utilize several techniques (e.g., Western blot analyses and immunocytochemistry) to assess the changes in several markers of phosphorylation that are important in cell communication (e.g., calcium-dependent protein kinase C, PKC; extracellular signal regulated kinases, ERK). This report serves to document research conducted under a Cooperative Trust Agreement between ARS and the California Walnut Board. We had shown previously under this agreement that walnut supplementation was effective in reversing the cognitive deficits in aged rats as compared to their non-supplemented counterparts. This year we assessed the effects of walnuts on a particular type of brain cell called a microglial cell that contributes to the �clean-up� of damaged cells in the brain. However, in aging and neurodegenerative diseases, these cells can become overactivated and begin to clean up healthy cells. We used BV-2 mouse microglial cells and showed that walnuts deactivate the cells and prevent cell death. We showed that these treatments are also effective in shutting down stress signals in hippocampal cells which are important in memory function reduced inflammatory markers and enhanced cellular calcium function in these cell models. To determine the components of walnuts that may be having beneficial effects in cells, we exposed BV-2 cells to inflammatory stressors to determine the protective roles of polyunsaturated fatty acids (PUFAs), specifically the omega-6 fatty acid linoleic acid (LA) and the omega-3 fatty acid, alpha-linolenic acid (ALA). PUFAs are essential components of neuronal cell membranes, maintaining membrane function critical for neurotransmitter communication within neural networks. Importantly, the extracts appeared to cause internalization of a particular receptor called a Toll-like receptor (TLR) . When these receptors were taken inside the cell by the walnut extracts, the access of inflammatory agents such as lipopolysaccharide to the receptor was blocked. This receptor is necessary for the inflammatory process to continue. The effects of walnut extract on BV-2 cells are novel and demonstrate that fruits and nuts can induce dramatic alterations in the stress responses of cells involved in age-related cognitive decline. This project is now completed and will be terminated in the annual report process.
Impacts
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Publications
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) Phase I. Assess the behavioral effects and blood levels of walnut fatty acids in the diets of the rats to determine the most effective supplementations of the walnuts in the diet to carry out experiments in Phase II of the proposal. Phase II. Aim-1 Determine the effects of walnuts (WL), blueberry (BB) or BB + WL supplementation on behavioral aging using paradigms sensitive to cognitive (short- and long-term memories) and motor behaviors. Aim 2: Determine the effects of these supplementations on calcium dependent neuronal signaling and neurogenesis (2b) and correlate these with alterations in behavioral parameters determined in A 1. Approach (from AD-416) The effects of BB dietary supplementation (2% BB extract in the diet), WL supplementation 2% WL extract in the diet) or WL + BB supplementation (1% each in the diet) will be examined on behavioral performance beginning 8 weeks after supplementation will have begun, in the rats using age-sensitive cognitive behaviors that are selective for reference and working memories. The effects of these supplementations on neurogenesis and differentiation will be examined using immunocytochemistry, bromodeoxyuridine) incorporation in hippocampus obtained from these animals. In addition we will utilize several techniques (e.g., Western blot analyses and immunocytochemistry) to assess the changes in several markers of phosphorylation that are important in cell communication (e.g., calcium-dependent protein kinase C, PKC; extracellular signal regulated kinases, ERK). Significant Activities that Support Special Target Populations We had shown previously under this agreement that walnut supplementation was effective in reversing the cognitive deficits in aged rats as compared to their non-supplemented counterparts. This year we assessed the effects of walnuts on a particular type of brain cell called a microglial cell that contributes to the �clean-up� of damaged cells in the brain. However, in aging and neurodegenerative diseases, these cells can become overactivated and begin to clean up healthy cells. We used BV- 2 mouse microglial cells and showed that walnuts deactivate the cells and prevent cell death. We showed that these treatments are also effective in shutting down stress signals in hippocampal cells which are important in memory function reduced inflammatory markers and enhanced cellular calcium function in these cell models. To determine the components of walnuts that may be having beneficial effects in cells, we exposed BV-2 cells to inflammatory stressors to determine the protective roles of polyunsaturated fatty acids (PUFAs), specifically the omega-6 fatty acid linoleic acid (LA) and the omega-3 fatty acid, alpha-linolenic acid (ALA). PUFAs are essential components of neuronal cell membranes, maintaining membrane function critical for neurotransmitter communication within neural networks. Importantly, the extracts appeared to cause internalization of a particular receptor called a Toll-like receptor (TLR) . When these receptors were taken inside the cell by the walnut extracts, the access of inflammatory agents such as lipopolysaccharide to the receptor was blocked. This receptor is necessary for the inflammatory process to continue. The effects of walnut extract on BV-2 cells are novel and demonstrate that fruits and nuts can induce dramatic alterations in the stress responses of cells involved in age-related cognitive decline.
Impacts
(N/A)
Publications
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Progress 10/01/07 to 09/30/08
Outputs
Progress Report Objectives (from AD-416) Phase I. Assess the behavioral effects and blood levels of walnut fatty acids in the diets of the rats to determine the most effective supplementations of the walnuts in the diet to carry out experiments in Phase II of the proposal. Phase II. Aim-1 Determine the effects of walnuts (WL), blueberry (BB) or BB + WL supplementation on behavioral aging using paradigms sensitive to cognitive (short- and long-term memories) and motor behaviors. Aim 2: Determine the effects of these supplementations on calcium dependent neuronal signaling and neurogenesis (2b) and correlate these with alterations in behavioral parameters determined in A 1. Approach (from AD-416) The effects of BB dietary supplementation (2% BB extract in the diet), WL supplementation 2% WL extract in the diet) or WL + BB supplementation (1% each in the diet) will be examined on behavioral performance beginning 8 weeks after supplementation will have begun, in the rats using age-sensitive cognitive behaviors that are selective for reference and working memories. The effects of these supplementations on neurogenesis and differentiation will be examined using immunocytochemistry, bromodeoxyuridine) incorporation in hippocampus obtained from these animals. In addition we will utilize several techniques (e.g., Western blot analyses and immunocytochemistry) to assess the changes in several markers of phosphorylation that are important in cell communication (e.g., calcium-dependent protein kinase C, PKC; extracellular signal regulated kinases, ERK). Significant Activities that Support Special Target Populations In our initial study we assessed Morris water maze and motor performance in senescent rats maintained for 8 weeks on a control diet or one containing 2% blueberry extract (BB), 2% walnut (WL) powder, or 1% BB and 1% walnut powder. Results indicated that, overall, either BB or walnut supplementation produced increases in the mean difference between Trial 1 and Trial 2 performance in the Morris water maze, indicating a greater degree of memory for the platform location in the supplemented groups than in the control group. Last year we examined higher doses of a walnut- supplemented diet to determine if they have similar beneficial properties on brain aging as do fruits and vegetables. Old (19 mo) F344 rats were fed a control, 6%, or 9% WL diet for 8 weeks prior to motor and cognitive testing. A 6% diet is equivalent to a human eating 1 oz of walnuts/day, which is the recommended amount to reduce LDL cholesterol. Combined results for these two studies for motor testing showed that the 2% WL diet improved performance on rod walking, while the 6% WL diet improved performance on the medium plank walk; the higher dose of 9% WL diet did not improve psychomotor performance and on the large plank actually impaired performance. All of the WL diets improved working memory in the Morris water maze, although the 9% diet showed impaired reference memory. Importantly, these findings show for the first time that the shorter chain fatty acids found in plants (e.g., walnuts) may have similar effects on cognition to the long chain fatty acids derived from animal sources that have been reported previously. In addition, this year we have been utilizing walnut oils in our hippocampal cells to determine their efficacy on the ability of the cells to extrude calcium following stimulation and exposure to an oxidative or inflammatory stressor. This work is aligned with NP 107 � Human Nutrition program component: 5. Health Promoting Properties of Plant and Animal Models.
Impacts
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Publications
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) Phase I. Assess the behavioral effects and blood levels of walnut fatty acids in the diets of the rats to determine the most effective supplementations of the walnuts in the diet to carry out experiments in Phase II of the proposal. Phase II. Aim-1 Determine the effects of walnuts (WL), blueberry (BB) or BB + WL supplementation on behavioral aging using paradigms sensitive to cognitive (short- and long-term memories) and motor behaviors. Aim 2: Determine the effects of these supplementations on calcium dependent neuronal signaling and neurogenesis (2b) and correlate these with alterations in behavioral parameters determined in A 1. Approach (from AD-416) The effects of BB dietary supplementation (2% BB extract in the diet), WL supplementation 2% WL extract in the diet) or WL + BB supplementation (1% each in the diet) will be examined on behavioral performance beginning 8 weeks after supplementation will have begun, in the rats using age-sensitive cognitive behaviors that are selective for reference and working memories. The effects of these supplementations on neurogenesis and differentiation will be examined using immunocytochemistry, bromodeoxyuridine) incorporation in hippocampus obtained from these animals. In addition we will utilize several techniques (e.g., Western blot analyses and immunocytochemistry) to assess the changes in several markers of phosphorylation that are important in cell communication (e.g., calcium-dependent protein kinase C, PKC; extracellular signal regulated kinases, ERK). Significant Activities that Support Special Target Populations This report serves to document research conducted under a Cooperative Trust Agreement between ARS and the California Walnut Board. The initial findings have been analyzed from our first study in which we assessed Morris water maze and motor performance in senescent rats maintained for 8 weeks on a control diet or one containing 2% blueberry extract (BB), 2% walnut powder, or 1% BB and 1% walnut powder. Results indicated that, overall, either BB or walnut supplementation produced increases in the mean difference between Trial 1 and Trial 2 performance in the Morris water maze, indicating a greater degree of memory for the platform location in the supplemented groups than in the control group. Initial analysis of the motor behavioral data indicated that there was some increase in performance in all of the supplemented groups in rotorod performance. This year we examined higher doses of a walnut-supplemented diet to determine if they have similar beneficial properties on brain aging as do fruits and vegetables. Old (19 mo) F344 rats were fed a control, 2%, 6%, or 9% walnut (WL) diet for 8 weeks prior to motor and cognitive testing. A 6% diet is equivalent to a human eating 1 oz of walnuts/day, which is the recommended amount to reduce LDL cholesterol. Results for the motor testing showed that the 2% WL diet improved performance on rod walking, while the 6% WL diet improved performance on the medium plank walk; the higher dose of 9% WL diet did not improve psychomotor performance and on the large plank actually impaired performance. All of the WL diets improved working memory in the Morris water maze, although the 9% diet showed impaired reference memory. We are currently assessing whether increased neurogenesis and/or alterations in stress signaling may be involved in the mechanisms of action through which the WL diets could be producing their effects. Importantly, these findings show for the first time that the shorter chain fatty acids found in plants (e.g., walnuts) may have similar effects on cognition to the long chain fatty acids derived from animal sources that have been reported previously. We are in the process of writing a paper on these findings and have also published one abstract. Additional details of this research can be found in the report for the parent CRIS 1950-51000-063- 00D Nutritional Modulation of Brain Aging and Cognitive Decline.
Impacts
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Publications
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Progress 10/01/05 to 09/30/06
Outputs
Progress Report 4d Progress report. This report serves to document research conducted under a Cooperative Trust Agreement between ARS and the California Walnut Commission. The initial findings have been analyzed from our first study in which we assessed Morris water maze and motor performance in senescent rats maintained for 8 weeks on a control diet or one containing 2% blueberry extract (BB), 2% walnut powder, or 1% BB and 1% walnut powder. Results indicated that, overall, either BB or walnut supplementation produced increases in the mean difference between Trial 1 and Trial 2 performance in the Morris water maze, indicating a greater degree of memory for the platform location in the supplemented groups than in the control group. Initial analysis of the motor behavioral data indicated that there was some increase in performance in all of the supplemented groups in rotorod performance. However, we are still analyzing these and other results and will also be
correlating these with our measurements of neuronal function. Additional details of this research can be found in the report for the parent project 1950-51000-063-00D Nutritional Modulation of Brain Aging and Cognitive Decline.
Impacts
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Publications
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