Seizure-prone EL/Suz mice exhibit physical and motor delays and heightened locomotor activity in response to novelty during development.
Seizure-prone EL/Suz mice have been studied as a model of multifactorial epilepsy for five decades. In prior behavioral studies, EL/Suz mice were shown to exhibit heightened locomotor activity, which implies a state of underlying hyperexcitability. The aim of the present study was to establish the premorbid behavioral development of basic motor skills and activity levels of EL/Suz mice, as compared with DDY mice, the control strain that is not seizure-prone. EL/Suz and DDY pups were monitored from Postnatal Day (PND) 3 to assess body weight, surface righting, negative geotaxis, forelimb grip strength, eye opening, habituation to a novel environment, and exploratory behavior in a two-compartment task. EL/Suz mice weighed less from PNDs 3 to 21 and exhibited delayed surface righting (PNDs 3, 5, 7) and negative geotaxis (PNDs 5, 7, 9) responses. EL/Suz and DDY mice differed in their habituation to a novel environment, with EL/Suz mice exhibiting higher activity, both within a single 10-minute session and across the 3 days of testing. EL/Suz and DDY mice also differed in the two-compartment task, with EL/Suz mice exhibiting increased locomotor activity and spending a greater amount of time in the light compartment. Thus, the present findings reveal that EL/Suz mice exhibit some developmental delays, altered habituation to a novel environment, and increased exploratory activity. Overall, the present results demonstrate that the behavioral and physiological phenotype of seizure-prone EL/Suz mice is deviant more than 2 months before the onset of seizure susceptibility.
McFadyen-Leussis
Melanie P
MP
Department of Psychology, Boston College, Chestnut Hill, MA 02467, USA. mcfadyme@bc.edu
Heinrichs
Stephen C
SC
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D004195:Disease Models, Animal; D005106:Exploratory Behavior / Q000502:physiology*; D005260:Female; D005552:Forelimb / Q000503:physiopathology; D006948:Hyperkinesis / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008817:Mice, Mutant Strains / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D010641:Phenotype; D011247:Pregnancy; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012018:Reflex / Q000502:physiology; D012640:Seizures / Q000235:genetics / Q000503:physiopathology* / Q000523:psychology; D013997:Time Factors