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The hippocampus is a complex brain structure and undergoes severe sclerosis and gliosis in temporal lobe epilepsy (TLE) as the most common type of epilepsy. The key features of the TLE may be reported in chronic animal models of epilepsy, such as pilocarpine model. Therefore, the current study was conducted in a rat pilocarpine model of acquired epilepsy. Two-dimensional gel electrophoresis based proteomic technique was used to compare the proteome map of the left and right hippocampus in both control and epileptic rats. Generally, 95 differentially expressed spots out of 1300 spots were identified in the hippocampus proteome using MALDI-TOF-TOF/MS. Within identified proteins, some showed asymmetric expression related to the mechanisms underlying TLE imposed by pilocarpine. Assessment of lateralization at the molecular level demonstrated that expression of proteins involved in dopamine synthesis was significantly more in the right hippocampus than the left one. In the epileptic model, reduction in dopamine pathway proteins was accompanied by an increase in the expression of proteins involved in polyamine synthesis, referring to a new regulating mechanism. Our results revealed changes in the laterality of protein expression due to pilocarpine-induced status epilepticus that could present some new proteins as potential candidates for antiepileptic drug design. Biological significance In the current study, two-dimensional gel electrophoresis (2-DE) based proteomic technique was used to profile changes in the left and right hippocampus proteome after pilocarpine induced status epilepticus. Spots of proteome maps for two hemispheres were excised and identified with MALDI-TOF-TOF/MS. Analysis of proteome map of the left and right hippocampus revealed a lateralization at the molecular level, in which the expression of proteins involved in dopamine synthesis and release were significantly more in right hippocampi than the left ones in the normal rats. Also, the expression of proteins involved in polyamine synthesis significantly increased in epileptic hippocampus (considerably higher in right hippocampi), whilst the proteins which included in dopamine pathways were decreased. Our results revealed changes in the laterality of protein expression due to pilocarpine-induced status epilepticus that could present some new proteins as potential candidates for antiepileptic drug design. [ABSTRACT FROM AUTHOR]

Instead of the La Niña events with no significant change in their surface expressions, the recent increasing frequency of central Pacific El Niño events is suggested to be related to global warming. There is yet no consensus on the impacts of the recent global warming on such asymmetric changes of El Niño‐Southern Oscillation (ENSO) events. Here we show the frequency of the extreme cold/moderate warm events both increases in the central equatorial Pacific over the past decades. We attribute the change of ENSO diversity to the positive cold tongue mode under recent global warming, which gives rise to an intensification, contraction, and westward shift of Walker circulation accompanied by an uplift of the thermocline. Our results propose a unified explanation for the changes of ENSO diversity under the recent global warming, which carries important implications for the relationship between global warming and ENSO. Plain Language Summary: El Niño‐Southern Oscillation (ENSO) events, characterized by sea surface temperature anomaly patterns in the tropical Pacific, have great global climate impacts by alternating between warm El Niño and cold La Niña phases. At the expense of the conventional El Niño peaking in the eastern Pacific, the recent increasing frequency of El Niño events with warming sea surface temperature anomalies concentrated in the central equatorial Pacific is suggested to be related to global warming, whereas for the La Niña events, there seems to be no significant change in their surface expressions. There is yet no consensus on the impacts of the recent global warming on such asymmetric changes of ENSO events. Our results show the increasing frequency of both the extreme cold and moderate warm events (ENSO diversity) can be ascribed to the positive cold tongue mode under the recent global warming. The positive cold tongue mode gives rise to an intensification, contraction, and westward shift of Walker circulation accompanied by an uplift of the thermocline, which enlarges the sea surface temperature morphology changes of El Niño but covers up the surface expression of La Niña. Key Points: The frequency of the extreme cold/moderate warm events increases in the central equatorial Pacific under recent global warmingThe positive cold tongue mode induces intensification, contraction, and westward shift of Walker circulation and uplift of the thermoclineThe positive cold tongue mode enlarges the sea surface temperature morphology changes of El Niño but covers up those of La Niña [ABSTRACT FROM AUTHOR]