What does low-intensity rTMS do to the cerebellum?

Non-invasive stimulation of the human cerebellum, such as by transcranial magnetic stimulation (TMS), is increasingly used to investigate cerebellar function and identify potential treatment for cerebellar dysfunction. However, the effects of TMS on cerebellar neurons remain poorly defined. We applied low-intensity repetitive TMS (LI-rTMS) to the mouse cerebellum in vivo and in vitro and examined the cellular and molecular sequelae. In normal C57/Bl6 mice, 4 weeks of LI-rTMS using a complex biomimetic high-frequency stimulation (BHFS) alters Purkinje cell (PC) dendritic and spine morphology; the effects persist 4 weeks after the end of stimulation. We then evaluated whether LI-rTMS could induce climbing fibre (CF) reinnervation to denervated PCs. After unilateral pedunculotomy in adult mice and 2 weeks sham or BHFS stimulation, VGLUT2 immunohistochemistry was used to quantify CF reinnervation. In contrast to sham, LI-rTMS induced CF reinnervation to the denervated hemicerebellum. To examine potential mechanisms underlying the LI-rTMS effect, we verified that BHFS could induce CF reinnervation using our in vitro olivocerebellar explants in which denervated cerebellar tissue is co-cultured adjacent to intact cerebella and treated with brain-derived neurotrophic factor (BDNF) (as a positive control), sham or LI-rTMS for 2 weeks. Compared with sham, BDNF and BHFS LI-rTMS significantly increased CF reinnervation, without additive effect. To identify potential underlying mechanisms, we examined intracellular calcium flux during the 10-min stimulation. Complex high-frequency stimulation increased intracellular calcium by release from intracellular stores. Thus, even at low intensity, rTMS modifies PC structure and induces CF reinnervation.

The regulatory BCL2 promoter polymorphism (-938C>A) is associated with relapse and survival of patients with oropharyngeal squamous cell carcinoma.

BACKGROUND: Expression of the antiapoptotic and antiproliferative protein B-cell lymphoma 2 (Bcl-2) has been repeatedly shown to be associated with better locoregional control and patients' survival in oropharyngeal squamous cell carcinoma (OSCC). A regulatory (-938C>A) single-nucleotide polymorphism (SNP) in the inhibitory P2 BCL2 gene promoter generates significantly different BCL2 promoter activities and has been associated with outcome in different malignancies. The aim of the present study was to analyze the possible influence of the (-938C>A) SNP on survival of patients suffering from OSCC. MATERIALS AND METHODS: One hundred and thirty-three patients with primary OSCC were retrospectively investigated. Bcl-2 expression of tumor cells was demonstrated by means of immunohistochemistry. Both the Bcl-2 expression and the (-938C>A) genotypes were correlated with the patients' survival. RESULTS: The (-938C>A) SNP was significantly related to Bcl-2 expression (P = 0.008). Kaplan-Meier curves revealed a significant association of the -938 SNP with relapse-free (P = 0.0283) and overall survival (P = 0.0247). Multiple Cox regression identified the BCL2 (-938CC) genotype as an independent prognostic factor for relapse [hazard ratio (HR) 1.898, P = 0.021] as well as for death in OSCC patients (HR 1.897, P = 0.013). CONCLUSIONS: The (-938C>A) SNP represents a potential novel prognostic marker in patients with OSCC that could help to identify a group of patients at high risk for relapse and death.

Neural circuit repair by low-intensity magnetic stimulation requires cellular magnetoreceptors and specific stimulation patterns.

Although electromagnetic brain stimulation is a promising treatment in neurology and psychiatry, clinical outcomes are variable, and underlying mechanisms are ill-defined, which impedes the development of new effective stimulation protocols. Here, we show, in vivo and ex vivo, that repetitive transcranial magnetic stimulation at low-intensity (LI-rTMS) induces axon outgrowth and synaptogenesis to repair a neural circuit. This repair depends on stimulation pattern, with complex biomimetic patterns being particularly effective, and the presence of cryptochrome, a putative magnetoreceptor. Only repair-promoting LI-rTMS patterns up-regulated genes involved in neuronal repair; almost 40% of were cryptochrome targets. Our data open a new framework to understand the mechanisms underlying structural neuroplasticity induced by electromagnetic stimulation. Rather than neuronal activation by induced electric currents, we propose that weak magnetic fields act through cryptochrome to activate cellular signaling cascades. This information opens new routes to optimize electromagnetic stimulation and develop effective treatments for different neurological diseases.

No association of the NF-kappaB1 -94ins/delATTG promoter polymorphism with relapse-free and overall survival in patients with squamous cell carcinomas of the head and neck region.

The transcription factor, nuclear factor-kappaB (NF-kappaB) is known to play a major role in immune response, inflammation and, via apoptosis and proliferation, also in oncogenesis. Transcription of NFKB1, which encodes the subunit p50/p105 of NF-kappaB, seems to be influenced by an insertion/deletion polymorphism in its promoter region. Accordingly, the goal of this study is to investigate whether this polymorphism can serve as a putative prognostic marker in patients with Squamous Cell Carcinomas of the Head and Neck region (HNSCC). The prognostic value of the -94ins/delATTG NFKB1 promoter polymorphism was analyzed in an unselected series of patients treated with curative intent for HNSCC, including all tumor stages with different therapeutical regimens. Genotyping was performed by means of pyrosequencing, using DNA from paraffin-embedded tissue samples from 364 patients with a median follow-up of 61 (2-143) months. The various genotypes were correlated with relapse-free and overall survival, as well as risk, compared to healthy volunteers. The NFKB1 polymorphism was not related to risk of HNSCC. Kaplan-Meier curves revealed no significant association between the -94ins/delATTG alleles and survival or disease progression of patients with HNSCC. In conclusion, the results suggest that the investigated NFKB1 promoter polymorphism has no prognostic impact on risk or clinical course in HNSCC.