Patrik Ernfors

Publications (2)7.43 Total impact

• Article: Suppressed Kindling Epileptogenesis and Perturbed BDNF and TrkB Gene Regulation in NT-3 Mutant Mice

  Eskil Elmér, Merab Kokaia, Patrik Ernfors, Istvan Ferencz, Zaal Kokaia, Olle Lindvall
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  ABSTRACT: In the kindling model of epilepsy, repeated electrical stimulations lead to progressive and permanent intensification of seizure activity. We find that the development of amygdala kindling is markedly retarded in mice heterozygous for a deletion of the neurotrophin-3 (NT-3) gene (NT-3+/− mice). These mice did not reach the fully kindled state (3rd grade 5 seizure) until after 28 ± 4 days of stimulation compared to 17 ± 2 days in the wild-type animals. The deficit in the NT-3+/− mice reflected dampening of the progression from focal to generalized seizures. The number of stimulations required to evoke focal (grade 1 and 2) seizures did not differ between the groups, but the NT-3 mutants spent a considerably longer period of time (13 ± 3 days) than wild-type mice (2 ± 1 days) in grade 2 seizures. As assessed by test stimulation 4–12 weeks after the 10th grade 5 seizure, kindling was maintained in the NT-3 mutants.In situhybridization showed 30% reduction of basal NT-3 mRNA levels and lack of upregulation of TrkC mRNA expression at 2 h after a generalized seizure in dentate granule cells of the NT-3+/− mice, whereas the seizure-evoked increase in brain-derived neurotrophic factor (BDNF) and TrkB mRNA levels was enhanced. These results indicate that endogenous NT-3 levels can influence the rate of epileptogenesis, and suggest a link between NT-3 and BDNF gene regulation in dentate granule cells.
  Experimental Neurology 06/1997; · 4.70 Impact Factor
• Article: Widespread increase of nerve growth factor protein in the rat forebrain after kindling-induced seizures

  Johan Bengzon, Stine Söderström, Zaal Kokaia, Merab Kokaia, Patrik Ernfors, Håkan Persson, Ted Ebendal, Olle Lindvall
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  ABSTRACT: Nerve growth factor (NGF) protein levels were determined in various forebrain regions using a two-site immunoassay following kindling-induced seizures. In the dentate gyrus the NGF content was significantly elevated 7 days after the last seizure (to 152% of control). In the piriform and parietal cortices, maximal increases were seen at 12 h (to 261% of control) and at 24 h (to 169% of control), respectively, and the NGF content was then normalized at 7 days. The increased production of NGF might be a protective response or could be involved in plastic changes underlying kindling epileptogenesis.
  Brain Research 09/1992; · 2.73 Impact Factor