Quality of rearing guides expression of behavioral and neural seizure phenotypes in EL mice

• Published in: Brain research Vol. 1260; pp. 84 - 93
• Main Authors: Leussis, Melanie P, Heinrichs, Stephen C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 13.03.2009; Elsevier
• Subjects: Animals; Anxiety - physiopathology; Biological and medical sciences; Body Weight; Cerebral Cortex - physiopathology; cFos; Cross-fostering; Disease Models, Animal; Emotionality; Exploratory Behavior - physiology; Female; Gene-Environment Interaction; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Hippocampus - physiopathology; Housing, Animal; Male; Maternal Behavior; Medical sciences; Mice; Mouse; Nervous system (semeiology, syndromes); Neurology; Neuronal Plasticity - physiology; Phenotype; Proto-Oncogene Proteins c-fos - metabolism; Seizure; Seizures - physiopathology; Species Specificity; Stress, Psychological; Maternal behavior; Emotionality; cFos; Seizure; Cross-fostering; Mouse; Affect affectivity; Nervous system diseases; Epilepsy; Rodentia; Emotion emotionality; Cerebral disorder; Vertebrata; Phenotype; Mammalia; Convulsion; Social interaction; Animal; Central nervous system disease; Neurological disorder
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2009.01.007

Abstract The present studies employed behavioral and neural markers of seizure-related plasticity to examine the relative contributions of genetic predisposition versus rearing environment in generating adult phenotypes in EL mice, a stress-induced animal model of epilepsy. Early environment was manipulated by cross-fostering pups of the EL strain to a seizure-resistant CD-1 control strain of mouse. The impact of changes in rearing quality on growth, exploratory and stress-reactivity phenotypes were examined, with a focus on the role of maternal care in shaping seizure susceptibility and neural cFos activation. Improvement in maternal care imposed by replacing biological EL dams with foster CD-1 mothers was sufficient to decrease pup mortality, to increase body weight gain (+ 0.1 g/day) and to delay the onset of seizure susceptibility in EL offspring beyond post-natal day 80–90. Moreover, hypoactivity in hippocampus and cortex among EL offspring cross-fostered to EL, but not CD-1 control, dams suggests that changes in rearing environment were accompanied by enduring changes in brain plasticity. Thus, neural and behavioral phenotypes of EL mice are dependent upon post-partum maternal care which if systematically enhanced can postpone seizure expression.