The Effects of Lidocaine Reversible Inactivation of the Dorsal Raphe Nucleus on Passive Avoidance Learning in Rats
Introduction: The role of serotonergic fibers in avoidance learning is controversial. Involvement of the dorsal raphe nucleus (DRN), the main source of hippocampal projecting serotonergic fibers in acquisition, consolidation and retrieval of passive avoidance (PA) learning, was investigated by funct...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Iran University of Medical Sciences
2011-08-01
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| Series: | Basic and Clinical Neuroscience |
| Subjects: | |
| Online Access: | http://bcn.iums.ac.ir/browse.php?a_code=A-10-1-73&slc_lang=en&sid=1 |
| _version_ | 1797282515876052992 |
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| author | Abdolrahman Sarihi Meisam Yazdi Behnam Heshmatian Iraj Salehi Gila Behzadi Nasser Naghdi Siamak Shahidi Alireza Komaki Abbas Haghparast Amir Hossein Emam |
| author_facet | Abdolrahman Sarihi Meisam Yazdi Behnam Heshmatian Iraj Salehi Gila Behzadi Nasser Naghdi Siamak Shahidi Alireza Komaki Abbas Haghparast Amir Hossein Emam |
| author_sort | Abdolrahman Sarihi |
| collection | DOAJ |
| description | Introduction: The role of serotonergic fibers in avoidance learning is controversial. Involvement of the dorsal raphe nucleus (DRN), the main source of hippocampal projecting serotonergic fibers in acquisition, consolidation and retrieval of passive avoidance (PA) learning, was investigated by functional suppression of this area. Materials and Methods: DRN functional inactivation was done by lidocaine (0.5μl, 2%) injection into the DRN, 5 min before training (n=10) and 5 (n=9), 90 (n=10) and 360 min (n=9) after acquisition trial. In the last experiment, lidocaine was injected into the DRN 5 min before the retrieval test , which was 48 h after the training (n=10). Results: Our results showed that PA learning was not impaired by DRN inactivation 5 min before training nor 5 and 360 min after training. Lidocaine injected 90 min after the acquisition trial significantly reduced avoidance of the dark compartment (P<0.001). Intra-DRN injection of lidocaine before retrieval significantly increased PA retention (P<0.001). Therefore, it seems that DRN has opposite effects on consolidation and retrieval of passive avoidance learning, but it has no effect on PA acquisition. Discussion: It is suggested that functional ablation of DRN may disrupt integrity of subcortical circuits participating in PA consolidation, but DRN inactivation by increasing brain awareness may affect PA retrieval in rats. |
| first_indexed | 2024-03-07T17:15:10Z |
| format | Article |
| id | doaj.art-bdabdea9652f4a07b217914655aa407f |
| institution | Directory Open Access Journal |
| issn | 2008-126X 2228-7442 |
| language | English |
| last_indexed | 2024-03-07T17:15:10Z |
| publishDate | 2011-08-01 |
| publisher | Iran University of Medical Sciences |
| record_format | Article |
| series | Basic and Clinical Neuroscience |
| spelling | doaj.art-bdabdea9652f4a07b217914655aa407f2024-03-02T23:28:19ZengIran University of Medical SciencesBasic and Clinical Neuroscience2008-126X2228-74422011-08-01242735The Effects of Lidocaine Reversible Inactivation of the Dorsal Raphe Nucleus on Passive Avoidance Learning in RatsAbdolrahman Sarihi0Meisam Yazdi1Behnam Heshmatian2Iraj Salehi3Gila Behzadi4Nasser Naghdi5Siamak Shahidi6Alireza Komaki7Abbas Haghparast8Amir Hossein Emam9 Introduction: The role of serotonergic fibers in avoidance learning is controversial. Involvement of the dorsal raphe nucleus (DRN), the main source of hippocampal projecting serotonergic fibers in acquisition, consolidation and retrieval of passive avoidance (PA) learning, was investigated by functional suppression of this area. Materials and Methods: DRN functional inactivation was done by lidocaine (0.5μl, 2%) injection into the DRN, 5 min before training (n=10) and 5 (n=9), 90 (n=10) and 360 min (n=9) after acquisition trial. In the last experiment, lidocaine was injected into the DRN 5 min before the retrieval test , which was 48 h after the training (n=10). Results: Our results showed that PA learning was not impaired by DRN inactivation 5 min before training nor 5 and 360 min after training. Lidocaine injected 90 min after the acquisition trial significantly reduced avoidance of the dark compartment (P<0.001). Intra-DRN injection of lidocaine before retrieval significantly increased PA retention (P<0.001). Therefore, it seems that DRN has opposite effects on consolidation and retrieval of passive avoidance learning, but it has no effect on PA acquisition. Discussion: It is suggested that functional ablation of DRN may disrupt integrity of subcortical circuits participating in PA consolidation, but DRN inactivation by increasing brain awareness may affect PA retrieval in rats.http://bcn.iums.ac.ir/browse.php?a_code=A-10-1-73&slc_lang=en&sid=1Dorsal RaphePassive AvoidanceReversible InactivationLearning And MemoryLidocaineRat. |
| spellingShingle | Abdolrahman Sarihi Meisam Yazdi Behnam Heshmatian Iraj Salehi Gila Behzadi Nasser Naghdi Siamak Shahidi Alireza Komaki Abbas Haghparast Amir Hossein Emam The Effects of Lidocaine Reversible Inactivation of the Dorsal Raphe Nucleus on Passive Avoidance Learning in Rats Basic and Clinical Neuroscience Dorsal Raphe Passive Avoidance Reversible Inactivation Learning And Memory Lidocaine Rat. |
| title | The Effects of Lidocaine Reversible Inactivation of the Dorsal Raphe Nucleus on Passive Avoidance Learning in Rats |
| title_full | The Effects of Lidocaine Reversible Inactivation of the Dorsal Raphe Nucleus on Passive Avoidance Learning in Rats |
| title_fullStr | The Effects of Lidocaine Reversible Inactivation of the Dorsal Raphe Nucleus on Passive Avoidance Learning in Rats |
| title_full_unstemmed | The Effects of Lidocaine Reversible Inactivation of the Dorsal Raphe Nucleus on Passive Avoidance Learning in Rats |
| title_short | The Effects of Lidocaine Reversible Inactivation of the Dorsal Raphe Nucleus on Passive Avoidance Learning in Rats |
| title_sort | effects of lidocaine reversible inactivation of the dorsal raphe nucleus on passive avoidance learning in rats |
| topic | Dorsal Raphe Passive Avoidance Reversible Inactivation Learning And Memory Lidocaine Rat. |
| url | http://bcn.iums.ac.ir/browse.php?a_code=A-10-1-73&slc_lang=en&sid=1 |
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