Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy
Pilocarpine-induced (320 mg/kg, ip) status epilepticus (SE) in adult (2-3 months) male Wistar rats results in extensive neuronal damage in limbic structures. Here we investigated whether the induction of a second SE (N = 6) would generate damage and cell loss similar to that seen after a first SE (N...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Divulgação Científica
2006-07-01
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| Series: | Brazilian Journal of Medical and Biological Research |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000700010 |
| _version_ | 1818299044791844864 |
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| author | L. Covolan L.E. Mello |
| author_facet | L. Covolan L.E. Mello |
| author_sort | L. Covolan |
| collection | DOAJ |
| description | Pilocarpine-induced (320 mg/kg, ip) status epilepticus (SE) in adult (2-3 months) male Wistar rats results in extensive neuronal damage in limbic structures. Here we investigated whether the induction of a second SE (N = 6) would generate damage and cell loss similar to that seen after a first SE (N = 9). Counts of silver-stained (indicative of cell damage) cells, using the Gallyas argyrophil III method, revealed a markedly lower neuronal injury in animals submitted to re-induction of SE compared to rats exposed to a single episode of pilocarpine-induced SE. This effect could be explained as follows: 1) the first SE removes the vulnerable cells, leaving behind resistant cells that are not affected by the second SE; 2) the first SE confers increased resistance to the remaining cells, analogous to the process of ischemic tolerance. Counting of Nissl-stained cells was performed to differentiate between these alternative mechanisms. Our data indicate that different neuronal populations react differently to SE induction. For some brain areas most, if not all, of the vulnerable cells are lost after an initial insult leaving only relatively resistant cells and little space for further damage or cell loss. For some other brain areas, in contrast, our data support the hypothesis that surviving cells might be modified by the initial insult which would confer a sort of excitotoxic tolerance. As a consequence of both mechanisms, subsequent insults after an initial insult result in very little damage regardless of their intensity. |
| first_indexed | 2024-12-13T04:44:58Z |
| format | Article |
| id | doaj.art-20fc29c29ec74d64b9f949df1793c812 |
| institution | Directory Open Access Journal |
| issn | 0100-879X 1414-431X |
| language | English |
| last_indexed | 2024-12-13T04:44:58Z |
| publishDate | 2006-07-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-20fc29c29ec74d64b9f949df1793c8122022-12-21T23:59:10ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X1414-431X2006-07-0139791592410.1590/S0100-879X2006000700010Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsyL. CovolanL.E. MelloPilocarpine-induced (320 mg/kg, ip) status epilepticus (SE) in adult (2-3 months) male Wistar rats results in extensive neuronal damage in limbic structures. Here we investigated whether the induction of a second SE (N = 6) would generate damage and cell loss similar to that seen after a first SE (N = 9). Counts of silver-stained (indicative of cell damage) cells, using the Gallyas argyrophil III method, revealed a markedly lower neuronal injury in animals submitted to re-induction of SE compared to rats exposed to a single episode of pilocarpine-induced SE. This effect could be explained as follows: 1) the first SE removes the vulnerable cells, leaving behind resistant cells that are not affected by the second SE; 2) the first SE confers increased resistance to the remaining cells, analogous to the process of ischemic tolerance. Counting of Nissl-stained cells was performed to differentiate between these alternative mechanisms. Our data indicate that different neuronal populations react differently to SE induction. For some brain areas most, if not all, of the vulnerable cells are lost after an initial insult leaving only relatively resistant cells and little space for further damage or cell loss. For some other brain areas, in contrast, our data support the hypothesis that surviving cells might be modified by the initial insult which would confer a sort of excitotoxic tolerance. As a consequence of both mechanisms, subsequent insults after an initial insult result in very little damage regardless of their intensity.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000700010Cell injuryStatus epilepticusEpilepsyPilocarpineSpontaneous seizures |
| spellingShingle | L. Covolan L.E. Mello Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy Brazilian Journal of Medical and Biological Research Cell injury Status epilepticus Epilepsy Pilocarpine Spontaneous seizures |
| title | Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy |
| title_full | Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy |
| title_fullStr | Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy |
| title_full_unstemmed | Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy |
| title_short | Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy |
| title_sort | assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy |
| topic | Cell injury Status epilepticus Epilepsy Pilocarpine Spontaneous seizures |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000700010 |
| work_keys_str_mv | AT lcovolan assessmentoftheprogressivenatureofcelldamageinthepilocarpinemodelofepilepsy AT lemello assessmentoftheprogressivenatureofcelldamageinthepilocarpinemodelofepilepsy |