Xiao-Qin Wang

The effects of ethanol extract of Bidens pilosa L. (EEB) on acute exercise fatigue and its underlying biochemical mechanism were investigated in this study. Sixty adult male ICR mice were divided into control, model, vitamin C (VC) 100, EEB40, EEB80, and EEB160 groups, receiving VC (100 mg/kg) or EEB (40, 80, 160 mg/kg) for 28 days (intragastrically, I.G.). The mice underwent tail-suspension, elevated plus maze (EPM), rotarod, and loaded swimming tasks and biochemical indices were measured. There were no significant differences in body weight, tail suspension time, EPM open arm time/entries and serum cortisone levels among the groups. Compared with the model group, there was an increase in rotarod latency in the VC100/EEB80 groups and an increase in loaded swimming time in the EEB80/EEB160 groups. Furthermore, the haptic and muscle glycogen levels decreased in the model group, while the haptic glycogen levels increased in the all VC/EEB groups. Similarly, the serum lactate and creatinine levels increased in the model group, but decreased in lactate (except for EEB160), creatinine (except for EEB40) and lactate dehydrogenase in the EEB80 group. In the liver, malonaldehyde (MDA) and oxidized glutathione (GSSG) levels increased in the model group; however, glutathione reductase (GR) (except for EEB40), glutathione (GSH) and GSH/GSSG ratios increased, with GSSG levels decreasing in all VC/EEB groups. In the quadriceps, the GR levels increased in the model, whereas it decreased in the VC100, EEB40 and EEB80 groups. These results suggest that EEB has anti-acute fatigue effect, potentially attributed to mitigate metabolite accumulation, enhancing glycogen reserves, and fortifying the antioxidant mechanism.

The ventral hippocampus (VH) and the basolateral amygdala (BLA) are both crucial in inhibitory avoidance (IA) memory. However, the exact role of the VH–BLA circuit in IA memory consolidation is unclear. This study investigated the effect of post-training reversible disconnection of the VH–BLA circuit in IA memory consolidation. Male Wistar rats with implanted guide cannulae were trained with a one-trial IA task, then received immediate intracerebral injections of muscimol or saline, and were tested 24 h later. Muscimol injection into the bilateral BLA, or the unilateral VH and contralateral BLA, but not the unilateral VH and ipsilateral BLA, significantly decreased the retention latencies (versus saline treatment). The results suggest that the VH–BLA circuit could be an important circuit to modulate consolidation of IA memory in rats.

In this study, one-trial step-through task was applied to reveal the effect of prefrontal infralimbic cortex GABAA receptor agitating on passive avoidance memory consolidation in rats. Immediately after training (with shock), GABAA receptor agonist, muscimol (0.5 μg/0.25 μL) or saline (0.25 μL) was infused into the test animal's infralimbic cortex, then, the latencies of rats stepping through the dark room were recorded. Meanwhile, local EEG power was adopted as index of the inactivation effect of muscimol. The step-through latencies of muscimol group were comparable(P>0.05)with saline group, but their local EEG power had decreased significantly (P<0.05). These results suggest that the inactivation of infralimbic cortex would not demolish the passive avoidance memory consolidation of rats.

Present work investigated the effects of tail suspension stress (TSS) on spatial memory acquisition, consolidation, and its reversal learning in mice. Eighty-one adult male KM mice were divided into four groups (each group including a TSS subgroup and its control subgroup): absolute spatial memory acquisition and consolidation groups (group AA and CA); relative spatial memory acquisition and consolidation groups (group AR and CR). TSS (20 min) was performed immediately before (acquisition) or after (consolidation) a daily training. Results showed that there was no significant difference between control animals and TSS animals in each group in early spatial memory training days (5-8 d of training). Along with training, the performance of control animals improved significantly, but the performance of TSS animals improved slightly (group AA, CA and AR) or even did not change (group CR) (P<0.01). Reversal learning was also impaired in TSS animals (P<0.01). The results indicated that TSS could impair spatial memory acquisition, consolidation and reversal learning (especially the relative spatial memory consolidation and its reversal learning) in mice.