Treacherous Astrocytes – a cause of Epilepsy?

Researchers at the University of Bonn have made a significant breakthrough in understanding the primary trigger behind the onset of temporal lobe epilepsy. The genesis lies in the early-stage malfunctioning of astrocytes, a type of brain cell. It leads to the uncoupling of astrocytic processes from each other, subsequently giving rise to the accumulation of potassium ions and neurotransmitters outside the cells, which in turn, leads to an excessive excitation of neurons, which is a hallmark of epilepsy.

Astrocytes, the star-shaped cells in the brain, are typically interconnected through specialized channels called gap junctions. These gap junctions predominantly consist of two types of proteins: connexin 43 and connexin 30. Employing a combination of patch-clamp recordings and diverse immunotechniques, the scientists in this study delved into the precise role of impaired gap junction channels in the development of epilepsy.

The findings underscore the crucial importance of addressing astrocyte dysfunction in order to combat epilepsy effectively. By rectifying the malfunctioning gap junction channels and restoring the connectivity between astrocytes, an avenue for potential therapeutic intervention against epilepsy emerges. This innovative strategy of targeting the root cause of the disorder marks a promising direction for future anti-epileptogenic treatments.

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Bedner P, Dupper A, Hüttmann K, Müller J, Herde MK, Dublin P, Deshpande T, Schramm J, Häussler U, Haas CA, Henneberger C, Theis M, & Steinhäuser C (2015). Astrocyte uncoupling as a cause of human temporal lobe epilepsy. Brain : a journal of neurology, 138 (Pt 5), 1208-22 PMID: 25765328

Shining a Light on Astrocytes!

Astrocytes have gained recognition for their ability to exhibit intricate intracellular calcium signals, and there has been a recent revelation regarding their rapid responsiveness in perceiving and modulating individual synapses. Scientists have achieved the remarkable feat of investigating the intricate network of astrocytes through the application of optical, pharmacological, and genetic methodologies. Particularly within the hippocampus, a brain region associated with memory and learning, astrocytes have demonstrated their role in orchestrating neuronal interactions.

In this context, the bursts of light emitted correspond to fluctuations in the levels of calcium ions within the astrocytes. These bursts of light serve as indicators, revealing the dynamic changes in the astrocytes’ internal calcium concentration. Notably, when neurons exhibit a surge of activity, there is a pronounced and rapid elevation in calcium levels within the neighbouring astrocytes. This surge in calcium concentration leads to a remarkable visual effect as the entire astrocyte illuminates, offering a visual representation of the intricate processes occurring within the cell.

This groundbreaking discovery sheds light on how calcium fluctuations in astrocytes contribute to neuronal communication and the underlying mechanisms of synaptic regulation.

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Haustein MD, Kracun S, Lu XH, Shih T, Jackson-Weaver O, Tong X, Xu J, Yang XW, O’Dell TJ, Marvin JS, Ellisman MH, Bushong EA, Looger LL, & Khakh BS (2014). Conditions and constraints for astrocyte calcium signaling in the hippocampal mossy fiber pathway. Neuron, 82 (2), 413-29 PMID: 24742463

The ‘Glass Brain’ shows neuronal firing in real-time!

Unveiling a mesmerizing leap in scientific visualization, a remarkable 3D ‘glass brain’ offers a captivating window into the dynamic spectacle of neurons firing in real-time. This groundbreaking presentation begins with the intricate mapping of the brain’s architecture through magnetic resonance imaging (MRI). The subsequent step involves the user donning a cap adorned with electrodes, strategically positioned to gauge disparities in electric potential, thereby recording the intricate symphony of brain activity. This cascade of neural events is then unveiled on a screen, through a vibrant array of colours, each hue representing the distinct frequencies of electrical energy that course through the intricate neural pathways, providing a visual narrative of the brain’s dynamic processes.

While the Glass Brain refrains from offering a direct window into an individual’s thoughts, it paints a broad picture of cerebral activity. Crafted as a Unity3D brain visualization, this innovative tool showcases both source activity and connectivity within the brain, inferred from high-density electroencephalogram (EEG) data through  SIFT and BCILAB, developed at the Swartz Center for Computational Neuroscience, University of California, San Diego, and Syntrogi Labs.

The project was developed as a collaboration with Adam Gazzaley and the Neuroscape Lab at UC San Francisco, with contributions from NVIDIA, StudioBee, and many others.

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Mullen T, Kothe C, Chi YM, Ojeda A, Kerth T, Makeig S, Cauwenberghs G, & Jung TP (2013). Real-time modeling and 3D visualization of source dynamics and connectivity using wearable EEG. 35th Annual International Conference of the IEEE Engineering in Biology and Medicine Society., 2013, 2184-7 PMID: 24110155

Neural Prosthesis gives Rodents ‘Extrasensory Perception’ for Infrared Light

A team of neuroscientists led by Dr. Miguel Nicolelis at Duke University has achieved a remarkable feat – giving rats the ability to perceive infrared light, which is normally invisible to them. They accomplished this by attaching an infrared detector to the rats’ heads, which was connected to microscopic electrodes implanted in the somatosensory cortex (S1). This discovery represents the first instance in which a brain-machine interface has enhanced the natural perceptual abilities of mammals.

Interestingly, during this experiment, it was observed that the neurons in the S1 region, when stimulated, still retained their usual tactile responsiveness to whisker deflection. This means that two different cortical representations coexisted in the rats’ S1 cortex, resulting in the creation of a novel bimodal processing region.

Moreover, the implications of this experimental paradigm extend beyond infrared light. It opens the door to the possibility of representing other stimuli, such as magnetic or radio waves, in the brain’s regions.

Researchers are hopeful that delving into the underlying mechanisms behind the formation of these novel processing regions will shed light on the phenomenon of brain plasticity, furthering our understanding of the brain’s incredible adaptability.

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Thomson EE, Carra R, & Nicolelis MA (2013). Perceiving invisible light through a somatosensory cortical prosthesis. Nature communications, 4 PMID: 23403583

‘Blade Runner’ can’t be far, MIT Scientists claim to Incept ‘False Memories’ into the Brain!

Neuroscientists at the Massachusetts Institute of Technology (MIT) have successfully pinpointed the specific cells responsible for housing memory imprints within the mouse hippocampus. In a recently published study, they have not only uncovered this intriguing phenomenon but have also managed to establish a distinct cluster of cells within the mouse hippocampus, specifically within the dentate gyrus. These cells have the remarkable capability to encode and represent a specific context, even to the extent of generating fabricated memories. The study’s focus was not solely on the neural aspects, but also on the behavioral interactions between these memories.

Through the application of optogenetics, the researchers activated these memory-engram-bearing cells in the hippocampus. This activation of engrams was harnessed to implant fabricated memories within the brains of the mice. The study showcased that reactivating these memory engrams didn’t merely trigger the behavioural recollection of the associated memory but also acted as a conditioned stimulus, leading to the formation of associative memories.

The MIT team is gearing up to embark on further investigations into the realm of memory distortion within the brain. Their continued research holds the potential to unravel more intricacies surrounding memory formation, recall, and even the malleability of memories within the neural landscape.

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Ramirez S, Liu X, Lin PA, Suh J, Pignatelli M, Redondo RL, Ryan TJ, & Tonegawa S (2013). Creating a false memory in the hippocampus. Science (New York, N.Y.), 341 (6144), 387-91 PMID: 23888038

‘The Matrix’ Becomes A Reality: Human Beings Can Be Transformed Into Batteries

Researchers at the Massachusetts Institute of Technology, have pioneered the development of glucose-powered bio-electronics. This innovation centres on the creation of a fuel cell that harnesses the energy potential of glucose. The applications of this technology are profound, as it opens doors to highly efficient brain implants, offering the promise of restoring mobility to paralyzed patients by facilitating the control of their arms and legs.

At the core of this technology is a fuel cell capable of extracting electrons from glucose molecules, thereby generating a small but essential electric current. The ingenuity of this invention is highlighted by the fact that the researchers have integrated the fuel cell onto a silicon chip, allowing for seamless integration with other necessary circuits crucial for the functioning of brain implants. Consequently, this glucose fuel cell, when combined with ultra-low-power electronics, possesses the unique capability of rendering brain implants and other medical devices entirely self-sustaining.

This study ushers a new era in the field of medical implants, where glucose derived from the human body itself serves as an unprecedented and sustainable energy source.

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Rapoport BI, Kedzierski JT, & Sarpeshkar R (2012). A glucose fuel cell for implantable brain-machine interfaces. PloS one, 7 (6) PMID: 22719888

Microsoft Researchers Working Toward Breakthroughs In Brain Tumor Diagnosis and Treatment

Microsoft researchers have joined forces with Cambridge University to pioneer a cutting-edge approach to aiding surgeons and oncologists in the treatment of glioblastoma, a challenging form of brain cancer. Their collaborative effort has given birth to advanced tools designed to streamline the medical process.

These innovative tools introduce a highly effective method of computer-assisted segmentation and fully automated 3-D tumour delineation. The current standard involves physicians meticulously outlining the tumour and its various components on 2-D slices of MRI scans, encompassing regions of actively growing tumour, areas where the tumour is outstripping its nutrient supply, and even the brain area surrounding the tumour showing signs of inflammation and swelling.

However, the collaboration has yielded a groundbreaking algorithm capable of replicating these manual annotations and generalizing them to previously uncharted patient data. This system can be trained to perform highly accurate and efficient segmentation.

The technique employed to segment the tumours into their constituent parts is a discriminative approach that relies on decision forests, incorporating context-aware spatial features. It simultaneously classifies individual tissue types, delivering computationally efficient results with low model complexity.

This collaboration between Microsoft and the University of Cambridge holds great promise in the field of medical technology and cancer treatment.

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Zikic D, Glocker B, Konukoglu E, Criminisi A, Demiralp C, Shotton J, Thomas OM, Das T, Jena R, & Price SJ (2012). Decision forests for tissue-specific segmentation of high-grade gliomas in multi-channel MR. MICCAI: International Conference on Medical Image Computing and Computer-Assisted Intervention, 15 (Pt 3), 369-76 PMID: 23286152

New Gene That ‘Influences’ Autism Identified

Scientists at the University of Basel have made a significant discovery by identifying a specific gene, neuroligin-3. When this gene is absent in mice, it disrupts neuronal signal transmission, ultimately leading to the development of behaviour patterns commonly associated with autism. These adverse effects are closely linked to the increased production of a specific neuronal glutamate receptor, which plays a crucial role in regulating the transmission of signals between neurons.

Excessive levels of this receptor hinder the adaptation of synaptic transmission during the learning process, causing disruptions in the brain’s long-term development and functionality.

Remarkably, the researchers were able to reverse these detrimental neuronal changes. When they reactivated the production of neuroligin-3, nerve cells decreased the production of glutamate receptors to a normal level, resulting in the disappearance of the structural defects in the brain typically observed in autism. These findings represent a significant stride in the field of drug development for the treatment of autism.

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Baudouin SJ, Gaudias J, Gerharz S, Hatstatt L, Zhou K, Punnakkal P, Tanaka KF, Spooren W, Hen R, De Zeeuw CI, Vogt K, & Scheiffele P (2012). Shared synaptic pathophysiology in syndromic and nonsyndromic rodent models of autism. Science (New York, N.Y.), 338 (6103), 128-32 PMID: 22983708

Brainwashing : A New Hope For Neurodegenerative Diseases?

Researchers from the University of Rochester have unearthed a novel mechanism for effectively eliminating extracellular proteins from the brain. In a pioneering study, the scientists delved into the intricate dynamics of cerebrospinal fluid (CSF) flow within a living mouse brain. While CSF serves the dual role of cushioning the brain and cleansing its tissue, the exact mechanisms of its movement and waste clearance have remained elusive.

Employing two-photon laser scanning microscopy, the researchers studied the CSF flow within live mouse brains, offering unprecedented insights.

The team introduced tracer molecules into the subarachnoid space, a fluid-filled cavity situated between the protective membranes enveloping the brain and spinal cord. This technique allowed them to comprehensively analyze the intricate pathways and dynamics of CSF movement within the brain in real-time.

The findings hold promise not only for furthering our understanding of brain health but also for potentially addressing neurodegenerative disorders. By unravelling the mysteries of how CSF operates within the brain, the groundwork is being laid for the development of innovative therapeutic strategies that could revolutionize the treatment landscape for those affected by these debilitating disorders.

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Iliff JJ, Wang M, Liao Y, Plogg BA, Peng W, Gundersen GA, Benveniste H, Vates GE, Deane R, Goldman SA, Nagelhus EA, & Nedergaard M (2012). A paravascular pathway facilitates CSF flow through the brain parenchyma and the clearance of interstitial solutes, including amyloid β. Science translational medicine, 4 (147) PMID: 22896675