title: Ketogenic diet exposure during the juvenile period increases social behaviors and forebrain neural activation in adult Engrailed 2 null mice.
abstract: Prolonged consumption of ketogenic diets (KD) has reported neuroprotective benefits. Several studies suggest KD interventions could be useful in the management of neurological and developmental disorders. Alterations in the Engrailed (En) genes, specifically Engrailed 2 (En2), have neurodevelopmental consequences and produce autism-related behaviors. The following studies used En2 knockout (KO; En2(-/-)), and wild-type (WT; En2(+/+)), male mice fed either KD (80% fat, 0.1% carbohydrates) or control diet (CD; 10% fat, 70% carbohydrates). The objective was to determine whether a KD fed from weaning at postnatal day (PND) 21 to adulthood (PND 60) would alter brain monoamines concentrations, previously found dysregulated, and improve social outcomes. In WT animals, there was an increase in hypothalamic norepinephrine content in the KD-fed group. However, regional monoamines were not altered in KO mice in KD-fed compared with CD-fed group. In order to determine the effects of juvenile exposure to KD in mice with normal blood ketone levels, separate experiments were conducted in mice removed from the KD or CD and fed standard chow for 2days (PND 62). In a three-chamber social test with a novel mouse, KO mice previously exposed to the KD displayed similar social and self-grooming behaviors compared with the WT group. Groups previously exposed to a KD, regardless of genotype, had more c-Fos-positive cells in the cingulate cortex, lateral septal nuclei, and anterior bed nucleus of the stria terminalis. In the novel object condition, KO mice previously exposed to KD had similar behavioral responses and pattern of c-Fos immunoreactivity compared with the WT group. Thus, juvenile exposure to KD resulted in short-term consequences of improving social interactions and appropriate exploratory behaviors in a mouse model that displays autism-related behaviors. Such findings further our understanding of metabolic-based therapies for neurological and developmental disorders.
authors.affiliation: Department of Animal Sciences, Graduate Program in Endocrinology and Animal Biosciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Verpeut
authors.affiliation: Department of Neuroscience and Cell Biology/Pediatrics, Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
authors.forename: Emanuel
authors.initials: E
authors.lastname: DiCicco-Bloom
authors.affiliation: Department of Animal Sciences, Graduate Program in Endocrinology and Animal Biosciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA. Electronic address: ntbello@aesop.rutgers.edu.
authors.forename: Nicholas T
authors.initials: NT
authors.lastname: Bello
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood; D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D001321:Autistic Disorder / Q000178:diet therapy / Q000235:genetics / Q000503:physiopathology; D015306:Biogenic Monoamines / Q000378:metabolism; D055423:Diet, Ketogenic / Q000379:methods*; D004195:Disease Models, Animal; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000172:deficiency* / Q000235:genetics; D009474:Neurons / Q000502:physiology*; D016548:Prosencephalon / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D012919:Social Behavior; D000099266:Engrailed 2 Protein
chemical_list: D020155:3-Hydroxybutyric Acid; D015306:Biogenic Monoamines; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D000099266:Engrailed 2 Protein
keywords: Adolescence; Dopamine; Low-carbohydrate diet; No-carbohydrate diet; Nutrition therapy; Serotonin; β-Hydroxybutyrate