Neuroscience
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Adverse early life experience is thought to increase an individual's susceptibility to mental health disorders, including anxiety and affective disorders, later in life. Our previous studies have shown that post-weaning social isolation of female rats during a critical period of development sensitizes an anxiety-related serotonergic dorsal raphe nucleus (DR) system in adulthood. Therefore, we investigated how post-weaning social isolation, in combination with a challenge with the anxiogenic drug, N-methyl-beta-carboline-3-carboxamide (FG-7142; a partial inverse agonist at the benzodiazepine allosteric site on the GABAA receptor), affects home cage behavior and serotonergic gene expression in the DR of female rats using in situ hybridization histochemistry. ⋯ In addition, FG-7142 decreased tph2 expression, measured 4h following treatment, in multiple subregions of the DR of group-reared rats but had no effect in isolation-reared rats. No treatment effects were observed on 5-HT1A receptor or serotonin transporter gene expression. These data suggest that adolescent social isolation alters tph2 expression in specific subregions of the DR and alters the effects of stress-related stimuli on behavior and serotonergic systems.
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The parapyramidal (ppy) region targets primarily the intermediolateral cell column and is probably involved in breathing and thermoregulation. In the present study, we tested whether ppy serotonergic neurons respond to activation of central and peripheral chemoreceptors. Bulbospinal ppy neurons (n=30) were recorded extracellularly along with the phrenic nerve activity in urethane/α-chloralose-anesthetized, paralyzed, intact (n=7) or carotid body denervated (n=6) male Wistar rats. ⋯ Most labeled cells (90%) showed strong tryptophan hydroxylase immunocytochemical reactivity, indicating that they were serotonergic. The present data reveal that peripheral chemoreceptors reduce the activity of the serotonergic premotor neurons located in the ppy region. It is plausible that the serotonergic neurons of the ppy region could conceivably regulate breathing automaticity and be involved in autonomic regulation.
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The kinematics of hand transport and grasp formation when reaching for and grasping cubes of different sizes were investigated in subjects with blepharospasm, subjects with torticollis and healthy subjects. Patients scaled peak grasp aperture accurately to object size, reflecting accurate sensorimotor integration of the intrinsic object characteristics. Likewise, the timing of peak grasp aperture in relation to the time of hand transport did not differ between patients and controls. ⋯ Increased movement times and slowed hand transport correlated significantly with symptom severity as assessed by the Unified Dystonia Rating Scale. The observation that the processing of peak grasp aperture was unaffected by blepharospasm or torticollis does not support the current concept of impaired sensorimotor integration. The slowing of hand transport appears to reflect a strategic response to compensate for insecurities in the execution of reaching movements to be found in focal dystonia of the face and neck.
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The Cdh23(erl/erl) mice are a novel mouse model for DFNB12 and are characterized by progressive hearing loss. In this study, erythropoietin (EPO) was given to the Cdh23(erl/erl) mice by intraperitoneal injection every other day from P7 for 7 weeks. Phosphate-buffered saline-treated or untreated Cdh23(erl/erl) mice were used as controls. ⋯ Meanwhile, DPOAE amplitudes in the EPO-treated Cdh23(erl/erl) mouse group were significantly higher than those of the untreated groups at f2 frequency of 15383 Hz at the three time points. Furthermore, the mean percentage of outer hair cell loss at middle through basal turns of cochleae was significantly lower in EPO-treated Cdh23(erl/erl) mice than in the untreated mice (P<0.05). This is the first report that EPO acts as an otoprotectant in a DFNB12 mouse model with progressive hearing loss.
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In this paper, we investigated event-related potentials (ERPs) evoked by visual stimuli with different three-dimensional visual depths. Before the experiment, tests for binocular advantage and for sensitivity to three-dimensional depth were carried out, respectively. At the same time, it should be ensured that the distinguishing degree of different depths is big enough. ⋯ It was interesting that there existed a positive correlation between the amplitude of the N2 component and the absolute value of the depth. Meanwhile, time-frequency analysis results showed that, in the time window of 150-200 ms after the onset of visual target stimuli, a similar positive correlation between the time-frequency distribution and the absolute value of the depth was also found. Additionally, in the time window of 200-600 ms after the onset of visual target stimuli, the alpha waves evoked under the five different depths were almost the same, which reflected that the cognitive process of three-dimensional visual depth might be finished by 200 ms after the onset of visual target stimuli, when the brain is in a state of relaxation.