Study of the profile of the neurotrophin BDNF in new leprosy cases before, during and after multidrug therapy

Brain-derived neurotrophic factor (BDNF) is a neurotrophin involved in the survival of neurons and growth and differentiation of dendrites and axons. The purpose of the present study was to evaluate plasma levels of BDNF of leprosy patients at different stages of multidrug therapy (MDT) in comparison with non-infected individuals. Plasma levels of BDNF were measured by ELISA in 30 healthy controls and 37 leprosy patients at diagnosis, during and after MDT. Plasma levels of BDNF tended to be higher in control subjects in comparison with leprosy patients, but this difference does not reach statistical significance. Interestingly, BDNF levels changed following MDT, achieving statistical difference only at the 2(nd) dose of MDT. These results indicate that BDNF may not be a surrogate marker of leprosy infection and/or related neuropathy. Further research is needed to investigate the meaning of BDNF level changes following leprosy treatment.     

Obsessive-compulsive symptoms among patients with blepharospasm and hemifacial spasm

Objective

The aim of this study was to compare the prevalence and the severity of different obsessive-compulsive disorder (OCD) symptoms reported by patients with blepharospasm (BSP) with those reported by patients with hemifacial spasm (HFS). We hypothesized that, since patients with BSP present a dysfunctional striato-thalamo-cortical circuitry, they would exhibit higher prevalence and/or greater severity of OCD symptoms than patients with HFS, a condition that results from peripheral irritation of the facial nerve.

Methods

Twenty-two patients with BSP and 31 patients with HFS were systematically evaluated by means of a sociodemographic and clinical questionnaire, the Mini International Neuropsychiatric Interview, the Obsessive-Compulsive Inventory-Revised, the Beck Depression Inventory (BDI), the Beck Anxiety Inventory (BAI) and the Mini Mental State Examination (MMSE). Diagnostic groups were compared using the Mann-Whitney U test for continuous variables and the Pearson's goodness-of-fit χ² test for categorical ones; Fisher's Exact Test was employed when indicated. Correlations between continuous variables were evaluated by means of Spearman coefficients.

Results

Patients with BSP and HFS were not significantly different in terms of sociodemographic characteristics and most neuropsychiatric features. Nevertheless, while checking was associated with shorter duration of BSP (Spearman's rho=−0.54; P=.01), hoarding correlated with a longer duration of HFS (Spearman's rho=0.40; P=.04). Length of abnormal movements did not correlate with the BDI, BAI and MMSE scores.

Conclusions

The finding that the severity of different OCD symptoms did not differ between the BSP and HFS groups suggests that BSP may not interfere significantly with behavioral components of the striato-thalamo-cortical circuitry. However, the fact that OCD symptoms were found to follow different courses in distinct diagnostic groups deserves further study.     

Stimulation of entorhinal cortex promotes adult neurogenesis and facilitates spatial memory

Deep brain stimulation (DBS) is an established therapeutic modality for the treatment of movement disorders and an emerging therapeutic approach for the treatment of disorders of mood and thought. For example, recently we have shown that DBS of the fornix may ameliorate cognitive decline associated with dementia. However, like other applications of DBS, the mechanisms mediating these clinical effects are unknown. As DBS modulates neurophysiological activity in targeted brain regions, DBS might influence cognitive function via activity-dependent regulation of hippocampal neurogenesis. Using stimulation parameters analogous to clinical high-frequency DBS, here we addressed this question in mice. We found that acute stimulation of the entorhinal cortex (EC) transiently promoted proliferation in the dentate gyrus (DG). Cells generated as a consequence of stimulation differentiated into neurons, survived for at least several weeks, and acquired normal dentate granule cell (DGC) morphology. Importantly, stimulation-induced promotion of neurogenesis was limited to the DG and not associated with changes in apoptotic cell death. Using immunohistochemical approaches, we found that, once sufficiently mature, these stimulation-induced neurons integrated into hippocampal circuits supporting water-maze memory. Finally, formation of water-maze memory was facilitated 6 weeks (but not 1 week) after bilateral stimulation of the EC. The delay-dependent nature of these effects matches the maturation-dependent integration of adult-generated DGCs into dentate circuits supporting water-maze memory. Furthermore, because the beneficial effects of EC stimulation were prevented by blocking neurogenesis, this suggests a causal relationship between stimulation-induced promotion of adult neurogenesis and enhanced spatial memory.     

<Emphasis Type="Italic">Valeriana officinalis</Emphasis> ameliorates vacuous chewing movements induced by reserpine in rats

Oral movements are associated with important neuropathologies as Parkinson’s disease and tardive dyskinesia. However, until this time, there has been no known efficacious treatment, without side effects, for these disorders. Thus, the aim of the present study was to investigate the possible preventive effects of V. officinalis, a phytotherapic that has GABAergic and antioxidant properties, in vacuous chewing movements (VCMs) induced by reserpine in rats. Adult male rats were treated with reserpine (1 mg/kg, s.c.) and/or with V. officinalis (in the drinking water, starting 15 days before the administration of the reserpine). VCMs, locomotor activity and oxidative stress measurements were evaluated. Furthermore, we carried out the identification of valeric acid and gallic acid by HPLC in the V. officinalis tincture. Our findings demonstrated that reserpine caused a marked increase on VCMs and the co-treatment with V. officinalis was able to reduce the intensity of VCM. Reserpine did not induce oxidative stress in cerebral structures (cortex, hippocampus, striatum and substantia nigra). However, a significant positive correlation between DCF-oxidation (an estimation of oxidative stress) in the cortex and VCMs (p < 0.05) was observed. Moreover, a negative correlation between Na⁺K⁺-ATPase activity in substantia nigra and the number of VCMs was observed (p < 0.05). In conclusion, V. officinalis had behavioral protective effect against reserpine-induced VCMs in rats; however, the exact mechanisms that contributed to this effect have not been completely understood.