Long-term Non-Anesthetic Preclinical Study Available Extra-Cranial Brain Activator (ECBA) System for the Future Minimally-Invasive Human Neuro-Modulation.

Long-term preclinical study available extracranial brain activator (ECBA) system, ECBAv2, is proposed for the non-anesthetic canine models. The titanium-packaged module shows enhanced durability, even after a year of implantation in the scalp. In addition, the wearable helmet type base station provides a stable experimental environment without anesthesia. In this work, HFS stimulation is induced to six canine models for 30 minutes every day over 4 weeks (10Hz, 40Hz and no stimulation for each pair of subjects). Pre- and post-HFS stimulation PET-CT image shows remarkable increases of glucose metabolism in the temporal and parietal lobes. Moreover, both the 40-Hz and 10-Hz groups shows noticeable increase and the former group has more increments than the latter. Our results establish that HFS stimulation definitely worked as facilitating brain activity which may affect memory and sensory skills, respectively.

Long-Term Non Anesthetic Preclinical Study Available Extra-Cranial Brain Activator (ECBA) System for the Future Minimally Invasive Human Neuro Modulation.

In recent years, electroceuticals have been spotlighted as an emerging treatment for various severe chronic brain diseases, owing to their intrinsic advantage of electrical interaction with the brain, which is the most electrically active organ. However, the majority of research has verified only the short-term efficacy through acute studies in laboratory tests owing to the lack of a reliable miniaturized platform for long-term animal studies. The construction of a sufficient integrated system for such a platform is extremely difficult because it requires multi-disciplinary work using state-of-the-art technologies in a wide range of fields. In this study, we propose a complete system of an implantable platform for long-term preclinical brain studies. Our proposed system, the extra-cranial brain activator (ECBA), consists of a titanium-packaged implantable module and a helmet-type base station that powers the module wirelessly. The ECBA can also be controlled by a remote handheld device. Using the ECBA, we performed a long-term non-anesthetic study with multiple canine subjects, and the resulting PET-CT scans demonstrated remarkable enhancement in brain activity relating to memory and sensory skills. Furthermore, the histological analysis and high-temperature aging test confirmed the reliability of the system for up to 31 months. Hence, the proposed ECBA system is expected to lead a new paradigm of human neuromodulation studies in the near future.

A minimally invasive wirelessly powered brain stimulation system for treating neurological disorders.

A novel minimally invasive wirelessly powered medical device, a magnetic induction extra-cranial brain stimulation (MI-ECBS) system is implemented for treating neurological disorders, Alzheimer's disease (AD) and Epilepsy. The proposed system provides 2 different types of clinically significant stimulation waveforms for the therapy. For high frequency stimulation (HFS), we used 1mA, 10Hz, rectangular, charge balanced (0.5msec pulse width) pulses for 3sec with 21sec rest (total 600 pulses). Subsequently, under same configuration, a low frequency stimulation (LFS; 1Hz, 600 pulses) protocol was applied to canine-animal models. As a result, complementary neuro-modulation, facilitation and an inhibition are successfully demonstrated with an EEG power spectrum monitoring and the stimulation delivery efficacy is enhanced to 39.57x comparing to conventional transcutaneous direct current stimulation (tDCS).

The ganglioside GQ1b regulates BDNF expression via the NMDA receptor signaling pathway.

Gangliosides are sialic acid-containing glycosphingolipids which play a role in neuronal functions. Among the gangliosides, tetrasialoganglioside GQ1b shows neurotrophic factor-like actions, such as increasing neurite outgrowth, cell proliferation, and long-term potentiation. In addition, we recently reported that GQ1b improves spatial learning and memory performance in naïve rats. However, it is still unknown how GQ1b exerts its diverse neuronal functions. Thus, we hypothesized that GQ1b might influence synaptic activity by regulating brain-derived neurotrophic factor (BDNF) expression, which is an important protein for synaptic plasticity and cognition. Interestingly, GQ1b treatment increased BDNF expression in GQ1b-null SH-SY5Y cell lines and rat primary cortical neurons. Additionally, we confirmed whether the observed effects were due to GQ1b or due to a ganglioside with fewer sialic acid molecules (GT1b and GD1b) created by the sialidases present on the plasma membranes, by directly applying GT1b and GD1b or GQ1b co-treated with a sialidase inhibitor. Treatment with GT1b or GD1b had no effect on BDNF expression, whereas co-treatment with a sialidase inhibitor and GQ1b significantly increased BDNF levels. Moreover, GQ1b restored the decreased BDNF expression induced by the ganglioside synthesis inhibitor, D-PDMP, in rat primary cortical neurons. GQ1b treatment significantly increased BDNF levels, whereas pretreatment with the N-methyl-d-aspartate (NMDA) receptor antagonist D-AP5 blocked the effects of GQ1b on BDNF expression, suggesting that GQ1b regulates BDNF expression via the NMDA receptor signaling. Finally, we performed an intracerebroventricular GQ1b injection, which resulted in increased prefrontal and hippocampal BDNF expression in vivo. These findings demonstrate, for the first time, that tetrasialoganglioside GQ1b regulates BDNF expression in vitro and in vivo.

Neuropep-1 ameliorates learning and memory deficits in an Alzheimer's disease mouse model, increases brain-derived neurotrophic factor expression in the brain, and causes reduction of amyloid beta plaques.

Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloid beta (Aß) deposits, hyperphosphorylated tau deposition, and cognitive dysfunction. Abnormalities in the expression of brain-derived neurotrophic factor (BDNF), which plays an important role in learning and memory formation, have been reported in the brains of AD patients. A BDNF modulating peptide (Neuropep-1) was previously identified by positional-scanning synthetic peptide combinatorial library. Here we examine the neuroprotective effects of Neuropep-1 on several in vitro neurotoxic insults, and triple-transgenic AD mouse model (3xTg-AD). Neuropep-1 protects cultured neurons against oligomeric Aß1-42, 1-methyl-4-phenylpyridinium, and glutamate-induced neuronal cell death. Neuropep-1 injection also significantly rescues the spatial learning and memory deficits of 3xTg-AD mice compared with vehicle-treated control group. Neuropep-1 treatment markedly increases hippocampal and cortical BDNF levels. Furthermore, we found that Neuropep-1-injected 3xTg-AD mice exhibit dramatically reduced Aß plaque deposition and Aß levels without affecting tau pathology. Neuropep-1 treatment does not alter the expression or activity of full-length amyloid precursor protein, α-, ß-, or γ-secretase, but levels of insulin degrading enzyme, an Aß degrading enzyme, were increased. These findings suggest Neuropep-1 may be a therapeutic candidate for the treatment of AD.

Mecamylamine attenuates dexamethasone-induced anxiety-like behavior in association with brain derived neurotrophic factor upregulation in rat brains.

Mecamylamine (MEC), which was initially developed as a ganglionic blocker for the treatment of hypertension has been investigated as a potent antagonist for most types of nicotinic acetylcholine receptors (nAChRs). Most studies of MEC have focused on its inhibitory effects for nAChRs; however its biological uses have recently been expanded to the treatment of psychological disorders accompanying anxiety-related symptoms. Although MEC shows obvious anxiolytic action, there is no clear evidence on its function. In this study, we investigated whether MEC affects brain derived neurotrophic factor (BDNF) expression in vitro and in vivo. MEC increased BDNF expression in differentiated SH-SY5Y cells and the cerebral cortex region of rat brains. To determine if the anxiolytic effect of MEC is associated with BDNF upregulation, the elevated plus maze (EPM) task was conducted in a dexamethasone (DEX)-induced anxiety model. MEC reduced DEX-induced anxiety-like behavior, and increased BDNF expression in the cerebral cortex of rats. These results suggest that the anxiolytic effect of MEC in EPM might be associated with BDNF upregulation in the cerebral cortex region of rats. The therapeutic efficacy of MEC for anxiety might be partly dependent on BDNF modulation.

Ganglioside GQ1b improves spatial learning and memory of rats as measured by the Y-maze and the Morris water maze tests.

Gangliosides are major components of cell membranes and are particularly enriched in the mammalian brain where they represent the major lipid constituents of the neuronal cell surface. In the central nervous system, gangliosides have a close connection to many neurophysiological functions related to neurogenesis, proliferation, synaptogenesis, and synaptic transmission. The previously reported effect of the tetra-sialoganglioside GQ1b in hippocampal CA1 neurons of brain slices showed that GQ1b enhanced ATP-induced long-term potentiation (LTP). However, there has been no clear evidence of the effects of GQ1b on learning and memory as measured using behavioral test. In the present study, we performed the Y-maze and the Morris water maze (MWM) tests to reveal the effects of GQ1b on spatial learning and memory following intracerebroventricular (ICV) injection of GQ1b. GQ1b-treated rats showed highly increased performance on the Y-maze and the MWM tests without any significant alteration of basal locomotor activity. Therefore, our behavioral data strongly suggest that GQ1b improves spatial learning and memory in rats. Also, these data support the previous finding that GQ1b treatment in hippocampal CA1 neurons of rodent brain slices increased ATP-induced LTP.

Effects of treadmill exercise on hypoactivity of the hypothalamo-pituitary-adrenal axis induced by chronic administration of corticosterone in rats.

The stress response alters behavior, autonomic function and secretion of multiple hormones, including CRF, ACTH, and glucocorticoid, through the HPA axis. Consecutive stress exposures lead to HPA axis dysregulation such as hyperactivity in Alzheimer's disease and depression, and hypoactivity in post-traumatic stress disorder. In the present study, we established a model of hypoactivated HPA axis in rat through chronic administration of corticosterone (40mg/kg, s.c.) for 19 consecutive days. In this model, CRF mRNA expression in the hypothalamus and ACTH levels in serum were significantly decreased by chronic administration of corticosterone. In addition, the effect of treadmill exercise was investigated in our hypoactivated HPA axis rat model. Treadmill exercise recovered the dysregulated hypoactivity of the HPA axis induced by corticosterone administration for 19 days. The results of the present study suggest that treadmill exercise may aid recovery of hypoactivated HPA axis dysregulation in psychological diseases such as post-traumatic stress disorder.