Abstract |
We previously demonstrated that ibotenate-stimulated polyphosphoinositide hydrolysis, determined as the accumulation of [3H]inositol 1-phosphate, significantly increased in the amygdala/pyriform cortex (AM/PC) 24 h and 7 days after the last seizure in AM-kindled rats. The present study examined whether the increase in ibotenate-stimulated polyphosphoinositide hydrolysis in the AM/PC is longer lasting. AM-kindled rats with a tripolar electrode implanted into the left AM and sham-operated controls were decapitated either 1, 2 or 4 weeks after the last seizure. Ibotenate (10(-3) M)-stimulated accumulation of [3H]inositol 1-phosphate significantly increased by 90% (P less than 0.01), 110% (P less than 0.001) and 73% (P less than 0.05) in the AM/PC 1, 2 and 4 weeks, respectively, after the last seizure. Four weeks after the last seizure, there were significant increases of a similar magnitude in the contralateral (right) AM/PC (by 83%, P less than 0.001) and the ipsilateral (left) AM/PC (by 63%, P less than 0.01). There was no change in the hippocampus or limbic forebrain at any of these times. Also 4 weeks after the last seizure, accumulation of [3H]inositol 1-phosphate significantly (P less than 0.05) increased at ibotenate concentrations of 2 x 10(-4) M, 5 x 10(-4) M and 10(-3) M in the kindled AM/PC. In light of the view that the AM/PC are the crucial brain structures for sustaining seizure susceptibility, the marked and lasting increase in the ibotenate-stimulated polyphosphoinositide hydrolysis coupled to excitatory amino acid receptors in the kindled AM/PC may be associated with the development of kindling and long-term maintenance of kindled events.
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Authors | K Akiyama, N Yamada, S Otsuki |
Journal | Brain research
(Brain Res)
Vol. 485
Issue 1
Pg. 95-101
(Apr 17 1989)
ISSN: 0006-8993 [Print] Netherlands |
PMID | 2541866
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Phosphatidylinositols
- Receptors, Amino Acid
- Receptors, Cell Surface
- Ibotenic Acid
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Topics |
- Amygdala
(metabolism, physiopathology)
- Animals
- Cerebral Cortex
(metabolism, physiopathology)
- Ibotenic Acid
- Kindling, Neurologic
- Male
- Phosphatidylinositols
(metabolism)
- Rats
- Rats, Inbred Strains
- Receptors, Amino Acid
- Receptors, Cell Surface
(metabolism, physiology)
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