Behavioural brain research
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The cholinergic system has been implicated in visuospatial attention but the exact role remains unclear. In visuospatial attention, bias refers to neuronal signals that modulate the sensitivity of sensory cortex, while disengagement refers to the decoupling of attention making reorienting possible. In the current study we investigated the effect of facilitating cholinergic neurotransmission by nicotine (Nicorette Freshmint 2mg, polacrilex chewing gum) on behavioral and electrophysiological indices of bias and disengagement. ⋯ Results show weak indications for a reduction of the reaction time validity effect by nicotine, but only for half of the sample in which the validity effect on the pretest was largest. Nicotine reduced the result of bias as indexed by a reduced P1 modulation by validity, especially in subjects with strong peripheral responses to nicotine. Nicotine did not affect ERP manifestations of the directing of bias (EDAN, LDAP) or disengagement (LPD).
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Among the non-motor phenomena of Parkinson's disease (PD) are depressive symptoms, with a prevalence of 40-70%. The reason for this high prevalence is not yet clear. The basal ganglia receives dopamine (DA) inputs from the substantia nigra pars compacta (SNpc), which is known to be impaired in PD patients. ⋯ Notably, correlations were found between 5-HT and DA levels and swimming, immobility, and sucrose preference. Our results indicate that 6-OHDA produced depressive-like behavior accompanied by striatal DA and hippocampal 5-HT reductions. Moreover, DA and 5-HT levels were strongly correlated with "emotional" impairments, suggesting the important participation of these neurotransmitters in anhedonia and behavioral despair after 6-OHDA-induced nigral lesions.
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Traumatic brain injury (TBI) is characterized by neuronal damage and commonly, secondary cell death, leading to functional and neurological dysfunction. Despite the recent focus of TBI research on developing therapies, affective therapeutic strategies targeting neuronal death associated with TBI remain underexplored. This study explored the efficacy of granulocyte-colony stimulating factor (G-CSF) as an intervention for improving cognitive deficits commonly associated with TBI. ⋯ The Morris Water Maze test was used to measure any treatment-associated changes in cognitive deficits observed in TBI animals at days 2-6 post-injury. Our findings demonstrate a significant improvement in cognitive performance in the G-CSF treated TBI animals within a week of injury, compared to untreated TBI, indicative of immediate and beneficial effect of G-CSF on cognitive performance post CHI. Our model suggests that early G-CSF exposure may be a promising therapeutic approach in recovery of cognitive deficits due to TBI.
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Several studies have demonstrated that the hippocampal N-methyl-D-aspartate type glutamate receptors (NMDARs) are necessary for the acquisition but not the retention of spatial reference memory. In contrast, a few studies have shown that post-acquisition repetitive intraperitoneal injections of an NMDAR antagonist facilitate the retention of spatial reference memory in a radial maze task. In the present study, we investigated the role of hippocampal NMDARs in the retention of spatial reference memories in Morris water maze. ⋯ In Experiment 2, D-AP5 was infused into the hippocampus 1 (immediate) or 7 (delayed) days after the training session. In the probe test, following the retention interval of 13 days, immediate infusion facilitated the performance in a manner similar to Experiment 1, whereas the delayed infusion did not. These findings suggest that hippocampal NMDARs play an important role in the deterioration of spatial reference memory.
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In many rodent species, including mandarin voles (Microtus mandarinus), the behavioral response to odors is regulated by a network of steroid-sensitive ventral forebrain nuclei including the medial amygdala (Me), bed nucleus of the striaterminalis (BNST), and medial preoptic area (MPOA). Although it is well-known that Me, BNST, and MPOA are closely interconnected, function independently in regulating odor-guided social behaviors, little is known about how order information is processed in the sub-regions of Me, BNST, and MPOA. ⋯ Serum testosterone levels were increased after 1h in males exposed to FVF. This study provides insight in understanding the relationship between female odor stimulation and Fos, AR and T expression in specific brain areas in males, and the regulatory role of testosterone in this biochemical process.