Ketogenic Diet’s Impact on Social & Repetitive Behaviors ...grooming in presence of mouse vs....
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Ketogenic Diet’s Impact on Social & Repetitive Behaviors in the BTBR Mouse Model of Autism Mira Nakhle ‘20, Roxana Alvarez ‘20, Dr. Susan Masino, Dr. David Ruskin Department of Neuroscience, Trinity College, 300 Summit Street, Hartford, CT 06106 INTRODUCTION: MATERIALS & METHODS: REFERENCES: Foley EM. Persistent Effects of the Ketogenic Diet on the Core Symptoms of Autism in BTBR Mice. Senior Thesis. Trinity College, 2016. Masino SA, Kawamura M, Wasser CD, Pomeroy LT, Ruskin DN. Adenosine, ketogenic diet and epilepsy: the emerging therapeutic relationship between metabolism and brain activity. Curr Neuropharmacol. 2009 Sep; 7(3):257-68. Ruskin DN, Svedova J, Cote JL, Sandau U, Rho JM, Kawamura M, Jr, Boison D, Masino SA. Ketogenic diet improves core symptoms of autism in BTBR mice. PLoS One. 2013;8:e65021. Ruskin DN, Fortin JA, Bisnauth S, Masino SA. Ketogenic diets improve behaviors associated with autism spectrum disorder in a sex-specific manner in the EL mouse. Physiol Behav. 2017;168:138-45. Ruskin DN, Murphy MI, Slade SL, Masino SA. Ketogenic diet improves behaviors in a maternal immune activation model of autism spectrum disorder. PLOS ONE. 2017;12:e0171643. Zablotsky B, Black LI, Maenner MJ, et al. Estimated prevalence of autism and other developmental disabilities following questionnaire changes in the 2014 National Health Interview Survey. National health statistics reports; no 87. Hyattsville, MD: National Center for Health Statistics. 2015. ACKNOWLEDGEMENTS: A special note of thanks to Lizzy Foley for her extensive work both in conducting testing and performing data analysis, as well as Dr. Susan Masino and Dr. David Ruskin for their advice and expert guidance. CONCLUSIONS: o Sociability: BTBR mice on the control diet were unexpectedly social: they spent a significant amount of time with the stranger mouse, which is contrary to the anticipated behavioral profile of a BTBR mouse. Results of mice on KD become challenging to interpret under this context, as the control results were unexpected. o The unexpected outcomes could be due to be a weakening of traits of the BTBR mice through generations of breeding. Additionally, environmental changes in the living space of the mice could create discrepancies from past findings. o Repetitive Behavior: Mice on the control diet during test 1 showed a higher degree of grooming in comparison to later tests, however tests 2 and 3 only show trends in grooming, and phase 2 grooming in both tests 2 and 3 are significantly lower than phase 2 in test 1. This suggests a beneficial diet effect that lasts after reversal. RESULTS: Figure 1A. Phase 1 shows no side preference, phase 2 shows preference to side with mouse (paired t test, p < 0.05).* Figure 2A. Phase 1 shows no side preference, phase 2 shows preference to side with mouse (paired t test, p < 0.05).* Sociability Testing (FRONTAL CONTACT) Repetitive Behavior Testing (GROOMING) 0 20 40 60 80 100 120 140 160 180 200 Frontal contact (s) Phase 1 Phase 2 Empty v. Empty Stranger mouse Empty Figure 3A. Phase 1 shows no side preference, phase 2 shows strong preference to side with mouse (paired t test, p < 0.01).** 0 20 40 60 80 100 120 140 160 180 200 Frontal contact (s) Phase 1 Phase 2 Empty v. Empty Stranger mouse Empty 0 20 40 60 80 100 120 140 160 180 200 Frontal contact (s) Phase 1 Phase 2 Empty v. Empty Stranger mouse Empty * * ** Phase 1; Baseline Phase 2; Sociability 0 50 100 150 200 250 Phase 1 Phase 2 Grooming (s) Figure 1B. Phase 2 shows increased grooming in presence of mouse vs. phase 1 (paired t test, p < 0.001).*** *** 0 50 100 150 200 250 Phase 1 Phase 2 Grooming (s) + Figure 2B. Phase 2 shows trend of increased grooming in presence of mouse vs. phase 1 (paired t test, p = 0.0571).(*) Phase 2 grooming significantly lower than Test 1. + 0 50 100 150 200 250 Phase 1 Phase 2 Grooming (s) ++ Figure 3B. Phase 2 shows trend of increased grooming in presence of mouse vs. phase 1 (paired t test, p = 0.0631).(*) Phase 2 grooming significantly lower than Test 1. ++ o Video scoring: observation of rodent activity in a clear, 3-chamber container. Videos of the session are recorded then analyzed through a specific time frame. o Frontal contact and grooming were measured on animals fed control diet, switched to ketogenic diet, and reversed back to control diet. Test 1: Mice fed control diet were social and showed increased grooming Test 2: Mice switched to ketogenic diet for 3 weeks did not change sociability but reduced grooming (*) Test 3: Mice reverted to control diet for 3 weeks did not change sociability and maintained reduced grooming (*) Phase 1; Control, determines if animal has a side preference. Phase 2; Test, examines frontal contact with another animal. o The latest data from the National Center for Health Statistics suggests 1 in 45 children have been diagnosed with autism spectrum disorder (ASD). Limited sociability and stereotyped repetitive behaviors are core symptoms (Zablotsky et al., 2015). o The ketogenic diet (KD) has been proven as an effective treatment for seizures in patients for decades. It has recently been found beneficial in patients and mouse models of ASD. Some patients with seizures experience lasting seizure suppression even when they revert to a normal diet; lasting benefits in ASD are unknown. Mechanisms altered by the shift to ketosis may have an impact on ASD symptoms (Masino et al., 2009; Ruskin et al., 2013, 2017a,b). o Here we examine sociability and repetitive behaviors before, during, and after treatment of KD in the BTBR mouse model of ASD. o Previous investigation on sociability compared time in a chamber with a mouse vs. an empty chamber. These experiments did not replicate the expected increase in sociability due to KD (Foley, 2016). o Here we reanalyzed the data to measure sociability as defined by frontal contact with another mouse, and stereotyped repetitive behavior, as measured by self-grooming.
Transcript of Ketogenic Diet’s Impact on Social & Repetitive Behaviors ...grooming in presence of mouse vs....
Ketogenic Diet’s Impact on Social & Repetitive Behaviors in the BTBR Mouse Model of Autism
Mira Nakhle ‘20, Roxana Alvarez ‘20, Dr. Susan Masino, Dr. David RuskinDepartment of Neuroscience, Trinity College, 300 Summit Street, Hartford, CT 06106
INTRODUCTION:
MATERIALS & METHODS:REFERENCES:Foley EM. Persistent Effects of the Ketogenic Diet on the Core Symptoms of Autism in BTBR Mice. Senior Thesis. Trinity College, 2016.Masino SA, Kawamura M, Wasser CD, Pomeroy LT, Ruskin DN. Adenosine, ketogenic diet and epilepsy: the emerging therapeutic relationship between metabolism and brain activity. Curr Neuropharmacol. 2009 Sep; 7(3):257-68.Ruskin DN, Svedova J, Cote JL, Sandau U, Rho JM, Kawamura M, Jr, Boison D, Masino SA. Ketogenic diet improves core symptoms of autism in BTBR mice. PLoS One. 2013;8:e65021.Ruskin DN, Fortin JA, Bisnauth S, Masino SA. Ketogenic diets improve behaviors associated with autism spectrum disorder in a sex-specific manner in the EL mouse. Physiol Behav. 2017;168:138-45.Ruskin DN, Murphy MI, Slade SL, Masino SA. Ketogenic diet improves behaviors in a maternal immune activation model of autism spectrum disorder. PLOS ONE. 2017;12:e0171643.Zablotsky B, Black LI, Maenner MJ, et al. Estimated prevalence of autism and other developmental disabilities following questionnaire changes in the 2014 National Health Interview Survey. National health statistics reports; no 87. Hyattsville, MD: National Center for Health Statistics. 2015.
ACKNOWLEDGEMENTS:A special note of thanks to Lizzy Foley for her extensive work both in conducting testing and performing data analysis, as well as Dr. Susan Masino and Dr. David Ruskin for their advice and expert guidance.
CONCLUSIONS:o Sociability: BTBR mice on the control diet were unexpectedly
social: they spent a significant amount of time with the stranger mouse, which is contrary to the anticipated behavioral profile of a BTBR mouse. Results of mice on KD become challenging to interpret under this context, as the control results were unexpected.
o The unexpected outcomes could be due to be a weakening of traits of the BTBR mice through generations of breeding. Additionally, environmental changes in the living space of the mice could create discrepancies from past findings.
o Repetitive Behavior: Mice on the control diet during test 1 showed a higher degree of grooming in comparison to later tests, however tests 2 and 3 only show trends in grooming, and phase 2 grooming in both tests 2 and 3 are significantly lower than phase 2 in test 1. This suggests a beneficial diet effect that lasts after reversal.
RESULTS:
Figure 1A. Phase 1 shows no side preference, phase 2 shows preference to side with mouse (paired t test, p < 0.05).*
Figure 2A. Phase 1 shows no side preference, phase 2 shows preference to side with mouse (paired t test, p < 0.05).*
Sociability Testing (FRONTAL CONTACT)
Repetitive Behavior Testing (GROOMING)
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Figure 3A. Phase 1 shows no side preference, phase 2 shows strong preference to side with mouse (paired t test, p <0.01).**
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100120140160180200
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tal c
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Phase 1 Phase 2
Empty v. EmptyStrangermouse
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100120140160180200
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**Phase 1; Baseline
Phase 2; Sociability
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Figure 1B. Phase 2 shows increased grooming in presence of mouse vs. phase 1 (paired t test, p < 0.001).***
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Figure 2B. Phase 2 shows trend of increased grooming in presence of mouse vs. phase 1 (paired t test, p = 0.0571).(*) Phase 2 grooming significantly lower than Test 1. +
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Figure 3B. Phase 2 shows trend of increased grooming in presence of mouse vs. phase 1 (paired t test, p = 0.0631).(*) Phase 2 grooming significantly lower than Test 1. ++
o Video scoring: observation of rodent activity in a clear, 3-chamber container. Videos of the session are recorded then analyzed through a specific time frame.
o Frontal contact and grooming were measured on animals fed control diet, switched to ketogenic diet, and reversed back to control diet.
Test 1: Mice fed control diet were social and showed increased grooming
Test 2: Mice switched to ketogenic diet for 3 weeks did not change sociability but reduced grooming
(*)
Test 3: Mice reverted to control diet for 3 weeks did not change sociability and maintained reduced grooming
(*)
Phase 1; Control, determines if animal has a side preference.
Phase 2; Test, examines frontal contact with another animal.
o The latest data from the National Center for Health Statistics suggests 1 in 45 children have been diagnosed with autism spectrum disorder (ASD). Limited sociability and stereotyped repetitive behaviors are core symptoms (Zablotsky et al., 2015).
o The ketogenic diet (KD) has been proven as an effective treatment for seizures in patients for decades. It has recently been found beneficial in patients and mouse models of ASD. Some patients with seizures experience lasting seizure suppression even when they revert to a normal diet; lasting benefits in ASD are unknown. Mechanisms altered by the shift to ketosis may have an impact on ASD symptoms (Masino et al., 2009; Ruskin et al., 2013, 2017a,b).
o Here we examine sociability and repetitive behaviors before, during, and after treatment of KD in the BTBR mouse model of ASD.
o Previous investigation on sociability compared time in a chamber with a mouse vs. an empty chamber. These experiments did not replicate the expected increase in sociability due to KD (Foley, 2016).
o Here we reanalyzed the data to measure sociability as defined by frontal contact with another mouse, and stereotyped repetitive behavior, as measured by self-grooming.
