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Finch SC, Boundy MJ, Webb NG, Harwood DT. The Effect of Experimental Protocol on the Toxicity of Saxitoxin in Mice. Toxins (Basel) 2023; 15:290. [PMID: 37104228 PMCID: PMC10146210 DOI: 10.3390/toxins15040290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/04/2023] [Accepted: 04/14/2023] [Indexed: 04/28/2023] Open
Abstract
Regulatory limits for toxins in shellfish are required to ensure the health of consumers. However, these limits also impact the profitability of shellfish industries making it critical that they are fit for purpose. Since human toxicity data is rarely available, the setting of regulatory limits is dependent on animal data which can then be extrapolated for use in the assessment of human risk. The dependence on animal data to keep humans safe means that it is critical that the toxicity data used is robust and of high quality. Worldwide, the protocols used in toxicity testing are varied, making it hard to compare results and adding confusion over which results better reflect the true toxicity. In this study, we look at the effect of mouse gender, i.p. dose volume, mouse body weight and feeding protocols (both acute and sub-acute) on the toxicity of saxitoxin. This allowed the effect of different variables used in toxicity testing to be understood and showed that the feeding protocol used in both acute and sub-acute studies greatly influenced the toxicity of saxitoxin in mice. Therefore, the adoption of a standard protocol for the testing of shellfish toxins is recommended.
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Affiliation(s)
- Sarah C. Finch
- AgResearch Ltd. Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand;
| | - Michael J. Boundy
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (M.J.B.); (D.T.H.)
| | - Nicola G. Webb
- AgResearch Ltd. Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand;
| | - D. Tim Harwood
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (M.J.B.); (D.T.H.)
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Estacio SM, Thursby MM, Simms NC, Orozco VA, Wu JP, Miawotoe AA, Worth WW, Capeloto CB, Yamashita K, Tewahade KR, Saxton KB. Food insecurity in older female mice affects food consumption, coping behaviors, and memory. PLoS One 2021; 16:e0250585. [PMID: 33914807 PMCID: PMC8084178 DOI: 10.1371/journal.pone.0250585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 04/09/2021] [Indexed: 11/18/2022] Open
Abstract
Food insecurity correlates with poor physical and mental health in older individuals, but has not been studied in a laboratory animal model. This explorative study developed a laboratory mouse model for analyzing the impact of food insecurity on food consumption, stress coping mechanisms, exploratory behavior, and memory. 18-month-old CD-1 female mice were assigned to either the food insecurity exposure condition (31 mice, 8 cages) or the control condition (34 mice, 8 cages) by cage. Over four weeks, the mice that were exposed to food insecurity received varied, unpredictable portions of their baseline food consumption (50%, 75%, 125%, 150% of baseline) for four days, followed by ad libitum access for three days, to approximate the inconsistent access to food observed in households experiencing food insecurity. Behavioral tasks were conducted before and after food insecurity exposure. Mice in the food insecurity exposure condition ate less compared to control mice during food insecurity (two-way ANOVA: group x time interaction: F7,93 = 10.95, P < 0.01) but ate more when given access to high fat food (two-way ANOVA, group x time interaction: F1,14 = 11.14, P < 0.01). Mice exposed to food insecurity increased active escaping behaviors in the forced swim test (repeated measures two-way ANOVA, group x time interaction: F1,63 = 5.40, P = 0.023). Exploratory behaviors were unaffected by food insecurity. Mice exposed to food insecurity showed a reduction in memory (repeated measures two-way ANOVA, group x time interaction: F1,61 = 4.81, P = 0.037). These results suggest that exposure to food insecurity is associated with differences in food consumption patterns, active coping mechanisms, and memory. The behavioral changes associated with food insecurity may inform research on food insecurity's impact on health in elderly humans.
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Affiliation(s)
- Samantha M. Estacio
- Department of Psychology, Santa Clara University, Santa Clara, California, United States of America
- Public Health Program, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Madalyn M. Thursby
- Department of Biology, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Noel C. Simms
- Department of Biology, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Vanessa A. Orozco
- Department of Biology, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Jessica P. Wu
- Public Health Program, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
- Department of Biology, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Alyssa A. Miawotoe
- Public Health Program, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
- Department of Biology, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Whitney W. Worth
- Public Health Program, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Claire B. Capeloto
- Public Health Program, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Kyla Yamashita
- Public Health Program, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
- Department of Biology, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Kayla R. Tewahade
- Public Health Program, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
| | - Katherine B. Saxton
- Public Health Program, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
- Department of Biology, Santa Clara University, Santa Clara University, Santa Clara, California, United States of America
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Glushchak K, Ficarro A, Schoenfeld TJ. High-fat diet and acute stress have different effects on object preference tests in rats during adolescence and adulthood. Behav Brain Res 2020; 399:112993. [PMID: 33152318 DOI: 10.1016/j.bbr.2020.112993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/30/2020] [Accepted: 10/28/2020] [Indexed: 12/16/2022]
Abstract
Meals of high-fat diet (HFD) during adolescence produce stronger impairments to memory during adolescence than adulthood, however recovery of memory from adolescent HFD is underexplored. In addition, many tests of rodent memory are confounded by aversive or food-based stimuli, making it difficult to determine baseline memory processing affected by HFD. Thus, we utilized three cohorts of rats (adolescent HFD, adult HFD, and adolescent HFD with recovery) to explore the effects of HFD at different ages on two traditional tests of memory based strictly on object exploration, novel object recognition and novel object location tests. To isolate stress as a variable, rats were tested either at baseline or with cold water swim occurring directly after object acquisition. Results show that preference for novel objects is impaired by stress across all groups, but HFD alone only impairs preference for novel objects during adolescence, although this recovers after switching to a control diet. Additionally, preference for an object in a new location is impaired by HFD in all age groups and fails to recover following diet change. Together the data suggest that stress and HFD differentially affect object preference, based on test type, except during the adolescent period. Because these tests are traditionally interpreted as memory processes dependent on two distinct brain regions, the hippocampus and perirhinal cortex, these results support that stress and HFD affect the hippocampus and perirhinal cortex differently. The data affirm that while perirhinal cortex-dependent behavior recovers, the adolescent period is susceptible to long-lasting dysfunctions of hippocampal behavior by HFD.
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Affiliation(s)
- Karina Glushchak
- Department of Psychological Science and Neuroscience, Belmont University, Nashville, TN, 37212, USA
| | - Alexandria Ficarro
- Department of Psychological Science and Neuroscience, Belmont University, Nashville, TN, 37212, USA
| | - Timothy J Schoenfeld
- Department of Psychological Science and Neuroscience, Belmont University, Nashville, TN, 37212, USA.
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Houtmeyers A, Duchateau L, Grünewald B, Hermans K. Reference intervals for biochemical blood variables, packed cell volume, and body temperature in pet rats (Rattus norvegicus) using point-of-care testing. Vet Clin Pathol 2016; 45:669-679. [DOI: 10.1111/vcp.12419] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Anneleen Houtmeyers
- Department of Pathology, Bacteriology and Avian Diseases; Ghent University; Merelbeke Belgium
| | - Luc Duchateau
- Department of Comparative Physiology and Biometrics; Ghent University; Merelbeke Belgium
| | | | - Katleen Hermans
- Department of Pathology, Bacteriology and Avian Diseases; Ghent University; Merelbeke Belgium
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