The expression of Fos following kainic acid-induced seizures is age-dependent.
The expression of limbic seizures following kainic acid (KA) administration starts at approximately postnatal day (P) 19 in rats. In this study we investigated whether the expression of Fos-like immunoreactivity (Fos-IR) in limbic regions occurs concomitantly with the behavioural expression of limbic seizures. Immunohistochemistry for c-Fos protein was examined 1, 2, 4, 12 and 24 h following seizure onset (KA-treated rats) or saline injections (controls) in immature and adult rats at P7, P13, P20 and P60. The expression of Fos-IR in limbic structures following KA-induced seizures is age-dependent. There is a strong and selective induction of Fos-IR in the CA3 region of the hippocampus following KA-induced seizures in rats at P7. However, the expression of Fos-IR in KA-treated rats at P13, P20 and P60 involved other hippocampal structures in addition to CA3. Abundant induction of Fos-IR was found in the CA1, CA3 and dentate gyrus (DG) in KA-treated rats at P13, P20 and P60. While immature rats at P7 and P13 showed very few or no Fos-IR neurons in most amygdala nuclei, rat pups at P20 showed strong induction of Fos-IR in the amygdala. Our results demonstrated that the induction of Fos-IR in most amygdala nuclei and the full expression of behavioural limbic seizures occur at the same developmental age, which is consistent with the idea that the amygdala may play a role in the modulation of limbic seizures.
Silveira
Diosely C
DC
Department of Neurology, Children's Hospital Boston and Harvard Medical School, 300 Longwood Avenue, Enders # 320, Boston, Massachusetts 02115, USA. diosely.silveira@tch.harvard.edu
Sogawa
Yoshimi
Y
Holmes
Gregory L
GL
D000367:Age Factors; D000679:Amygdala / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism*; D000818:Animals; D000906:Antibodies; D001522:Behavior, Animal; D018891:Dentate Gyrus / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D004827:Epilepsy / Q000139:chemically induced / Q000378:metabolism*; D018690:Excitatory Amino Acid Agonists; D007608:Kainic Acid; D008125:Locus Coeruleus / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism
D000906:Antibodies; D018690:Excitatory Amino Acid Agonists; D016760:Proto-Oncogene Proteins c-fos; D007608:Kainic Acid