BackgroundThe left cerebral hemisphere predominance in human focal epilepsy has been observed in a few studies, however, there is no related systematic study in epileptic animal on hemisphere predominance. The main goal of this paper is to observe if the epileptiform discharges (EDs) of Pilocarpine-induced epileptic rats could present difference between left hemisphere and right hemisphere or not.MethodsThe electrocorticogram (ECoG) and electrohippocampogram (EHG) from Pilocarpine-induced epileptic rats were recorded and analyzed using Synchronization likelihood (SL) in order to determine the synchronization relation between different brain regions, then visual check and cross-correlation analysis were adopted to evaluate if the EDs were originated more frequently from the left hemisphere than the right hemisphere.ResultsThe data show that the synchronization between left-EHG and right-EHG, left-ECoG and left-EHG, right-ECoG and right-EHG, left-ECoG and right-ECoG, are significantly strengthened after the brain functional state transforms from non-epileptiform discharges to continuous-epileptiform discharges(p < 0.05). When the state transforms from continuous EDs to periodic EDs, the synchronization is significantly weakened between left-ECoG and left-EHG, left-EHG and right-EHG (p < 0.05). Visual check and the time delay (τ) based cross-correlation analysis finds that 10 out of 13 EDs have a left predominance (77%) and 3 out of 13 EDs are right predominance (23%).ConclusionThe results suggest that the left hemisphere may be more prone to EDs in the Pilocarpine-induced rat epilepsy model and implicate that the left hemisphere might play an important role in epilepsy states transition.

The aim of the present study was to evaluate handwashing technique, bacteriology, and factors influencing handwashing technique of 86 stable chronic peritoneal dialysis (PD) patients from Yiwu City in Southeast China. Based on the "Hygienic standard for disinfection in the hospital", we also performed sampling for bacteriology from PD operators after they washed their hands. We compared their clinical features including the pathogenic bacteria of their previous peritonitis episodes and their handwashing evaluation results according to their bacteriologic sampling results. 65% of patients turned off the tap by bare hand, and 74% did not follow the six-step handwashing method. Dialysis duration longer than 6 months (P = 0.04) and lower income (P = 0.05) were independent risk factors for higher handwashing error scores. The overall rate of appropriate handwashing, according to the "hygienic standard for disinfection in the hospital" was 26%. The bacteriologic sampling results showed that the most common pathogenic bacterium was Staphylococcus aureus (92%). PD operators whose hand bacteria culture was qualified contained a lower proportion of participants with advanced age (P = 0.07). Patients with repeated peritonitis occurrence had a significantly higher score on handwashing error (P < 0.01) and were more likely to develop Staphylococcus infection. We found that in Yiwu city patients on dialysis for more than 6 months, were of low income and had multiple prior episodes of PD peritonitis had poor handwashing compliance. Elderly patients had higher rates of positive bacterial culture (Staphylococcus) from their hands.

Visual lateralization is a typical characteristic of many vertebrates, however, its underlying dynamic neural mechanism is unclear. In this study, predatory responses and dynamic brain activities were evaluated in the Emei music frog (Babina daunchina) to assess the potential eye preferences and its underlying dynamic neural mechanism, using behavioral and electrophysiological experiments, respectively. To do this, when prey stimulus (live cricket and leaf as control) was moved around the frogs in both clockwise and anticlockwise directions at constant velocity, the number of predatory responses were counted and Electroencephalogram (EEG) absolute power spectra for each band was measured for the telencephalon, diencephalon and mesencephalon, respectively. The results showed that (1) no significant difference of the number of predatory responses could be found for control (leaf), however, the number of predatory responses for the right visual field (RVF) were significantly greater than those for the left visual field (LVF) when the live cricket was moved into RVF clockwise; (2) compared with no-stimulus in the visual field and stimulus in LVF, the power spectra of each EEG band was greater when the prey stimulus was moved into RVF clockwise; and (3) the power spectra of theta, alpha and beta bands in the left diencephalon were significantly greater than those of the right counterpart for clockwise direction, however, relatively less similar significant differences presented for anticlockwise direction. Together, the results suggested that right-eye preferences for predatory behaviors existed in the music frogs, and that the dynamics of EEG oscillations might underlie this right-eye/left-hemisphere advantage.

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Aggressive behavior is one of congenital social behaviors in many species, which could be promoted by social neglect or isolation in the early stages of life. Many brain regions including the medial prefrontal cortex (mPFC), medial amygdala (MeA) and ventromedial hypothalamus (VMH) are demonstrated to relate to aggressive behavior; however, the dynamic patterns of neural activities during the occurrence of this behavior remain unclear. In this study, 21-day-old male CD-1 mice were reared in social isolation conditions and cohousing conditions for two weeks. Aggressive behaviors of each subject were estimated by the resident–intruder test. Simultaneously, the local field potentials of mPFC, MeA and VMH were recorded for exploring differences in the relative power spectra of different oscillations when aggressive behaviors occurred. The results showed that the following: (1) Compared with the cohousing mice, the socially isolated mice exhibited more aggression. (2) Regardless of “time condition” (pre-, during- and post- attack), the relative power spectra of beta band in the cohousing mice were significantly greater than those in the socially isolated mice, and inversely, the relative power spectra of gamma band in the cohousing mice were significantly smaller than those in the socially isolated mice. (3) The bilateral mPFC exhibited significantly smaller beta power spectra but greater gamma power spectra compared with other brain areas regardless of rearing patterns. (4) For the right VMH of the socially isolated mice, the relative power spectra of the gamma band during attacks were significantly greater than those before attack. These results suggest that aggressive behaviors in mice could be shaped by rearing patterns and that high-frequency oscillations (beta and gamma bands) may engage in mediating aggressive behaviors in mice.