Altered flurothyl seizure induction latency, phenotype, and subsequent mortality in a mouse model of juvenile neuronal ceroid lipofuscinosis/Batten disease

Purpose: Juvenile neuronal ceroid lipofuscinosis (JNCL), or Batten disease, is a pediatric neurodegenerative disease characterized by vision loss, seizure activity, cognitive decline, and premature death. Discovery of the Batten disease-related gene, CLN3, led to creation of a Cln3 protein-deficient mouse model (CLn3(-/-)), which recapitulates some of the histopathologic characteristics of the human condition. We hypothesized that lack of Cln3 would alter seizure-related behavioral parameters. Methods: Using flurothyl gas inhalation, we examined seizure-induction latencies in Cln3(-/-) mice and wildtype (wt) controls at time points that represent late neonatal, immature, mature, and aged time points. We examined latency to first myoclonic Jerk (LMJ), latency to loss of posture (LOP), and subsequent mortality. Results: Our results demonstrate an age-dependent alteration of seizure-induction latencies in Cln3(-/-). Immature Cln(-/-) mice aged 35-42 days had an increased latency to both LMJ and LOP compared with age-matched wt controls. There were no significant latency differences between Cln3(-/-) and wt at other time points examined. Mortality after generalized seizure was high in both Cln3(-/-) and wt animals at late neonatal and immature developmental stages. No mortality was seen in wt mice past maturity at 6 weeks. Mature and aged Cln3(-/-) animals retained a vulnerability to death after seizure activity. Conclusions: These results suggest that a deficiency of Cln3 protein in the Batten model mice may result in age-dependent alteration of the neuroanatomic and biochemical substrates involved in seizure propagation and recovery. This may be important in understanding seizures, neurodegeneration, and premature death in human Batten disease.