Postischemic fish oil treatment restores long-term retrograde memory and dendritic density: An analysis of the time window of efficacy.
We reported that fish oil (FO) prevented the loss of spatial memory caused by transient, global cerebral ischemia (TGCI), provided the treatment covered the first days prior to and after ischemia. Continuing these studies, trained rats were subjected to TGCI, and FO was administered for 10days, with a time window of efficacy (TWE) of 4, 8 or 12h post-ischemia. Retrograde memory was assessed up to 43days after TGCI. In another experiment, ischemic rats received FO with a 4- or 12-h TWE, and dendritic density was assessed in the hippocampus and cerebral cortex. The brain lipid profile was evaluated in sham-operated and ischemic rats that were treated with FO or vehicle with a 4-h TWE. Ischemia-induced retrograde amnesia was prevented by FO administration that was initiated with either a 4- or 8-h TWE. Fish oil was ineffective after a 12-h TWE. Independent of the TWE, FO did not prevent ischemic neuronal death. In the hippocampus, but not cerebral cortex, TGCI-induced dendritic loss was prevented by FO with a 4-h TWE but not 12-h TWE. The level of docosahexaenoic acid almost doubled in the hippocampus in ischemic, FO-treated rats (4-h TWE). The data indicate that (i) the anti-amnesic effect of FO can be observed with a TWE of up to 8h, (ii) the stimulation of dendritic neuroplasticity may have contributed to this effect, and (iii) DHA in FO may be the main active constituent in FO that mediates the cognitive and neuroplasticity effects on TGCI.
['Bacarin|Cristiano Correia|CC|', 'Godinho|Jaqueline|J|', 'de Oliveira|Rúbia Maria Weffort|RMW|', 'Matsushita|Makoto|M|', 'Gohara|Aline Kirie|AK|', 'Cardozo-Filho|Lúcio|L|', 'Lima|Jéssica de Carvalho|JC|', 'Previdelli|Isolde Santos|IS|', 'Melo|Silvana Regina|SR|', 'Ribeiro|Matheus Henrique Dal Molin|MHDM|', 'Milani|Humberto|H|']
D000648:Amnesia, Retrograde D000818:Animals D002540:Cerebral Cortex D003712:Dendrites D004195:Disease Models, Animal D004281:Docosahexaenoic Acids D005395:Fish Oils D006624:Hippocampus D002546:Ischemic Attack, Transient D008297:Male D057567:Memory, Long-Term D019636:Neurodegenerative Diseases D009473:Neuronal Plasticity D018696:Neuroprotective Agents D018697:Nootropic Agents D017208:Rats, Wistar D013997:Time Factors
Fish oil Global cerebral ischemia Retrograde amnesia Dendritic loss Dendritic neuroplasticity Memory protection