Scientists at the University of Bonn have unearthed the root cause for the development of temporal lobe epilepsy! At an early stage, astrocytes are uncoupled from each other, this results in the extracellular accumulation of potassium ions and neurotransmitters, which cause hyper-excitability of the neurons. Astrocytes are connected by gap junction channels composed mainly of the gap junction protein (connexin 43 and connexin 30). In this study, researchers combined patch-clamp recordings with various immunotechniques to decipher of the role of impaired gap junctions channels in the etiology of epilepsy. So, the restoration of the astrocyte dysfunction could be a novel strategy for anti-epileptogenic therapeutic intervention.
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
Astrocytes are known to display dynamic intracellular Ca2+ signals, and it has recently been shown that astrocytes rapidly sense and regulate single synapses. Researchers could able to study astrocytic network using optical, pharmacological and genetic tools. Astrocytes in the hippocampus, found to be regulating neuronal conversations. Here, the flashes of light indicate changes in calcium levels within the astrocytes. When neurons show a burst of activity, calcium levels dramatically increase in the astrocyte, lighting up the entire cell.
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
Stunning 3D ‘glass brain’ shows neurons firing off in real-time. The structure of the brain is mapped using magnetic resonance imaging (MRI). The user then wears cap covered with electrodes that measure differences in electric potential to record brain activity. This activity is revealed on-screen. The different colors represent the different frequencies of electrical energy in the brain, as well as the paths by which that energy moves around.
The Glass Brain can’t be used to show exactly what the user is thinking, but can paint a broad picture of brain activity. The Glass Brain is a Unity3D brain visualization that displays source activity and connectivity, inferred in real-time from high-density EEG using methods implemented in 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.
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
A team of researchers at the Nicolelis Laboratory based in the Duke University have given rats the ability to perceive infrared light, normally invisible to them. They attached an infrared detector to the head wired to microscopic electrodes implanted in the somatosensory cortex (S1). This achievement represents the first time a brain-machine interface has augmented natural perceptual capabilities in mammals.
Interestingly, it was observed that neurons in the stimulated regions of S1 maintained their normal tactile ability to respond to whisker deflection. Therefore, two different cortical representations, became superimposed on the animal’s S1 cortex, creating a novel bimodal processing region.
Moreover, this experimental paradigm could be expanded to other stimulus such as magnetic or radio waves to be represented in brain region. Researchers hope that studying the underlying mechanisms in which the brain is creating a novel processing region would be helpful to further investigate the phenomenon of brain plasticity.
Thomson EE, Carra R, & Nicolelis MA (2013). Perceiving invisible light through a somatosensory cortical prosthesis. Nature communications, 4 PMID: 23403583
Neuroscientists at the Massachusetts Institute of Technology have identified the cells where memory traces are stored in the mouse hippocampus. In a study published recently, they reported to establish a population of cells in the dentate gyrus of the mouse hippocampus that encoded a particular context and were able to generate a false memory and study its neural and behavioral interactions with true memories. The researchers optogenetically activated the memory engram bearing cells in the hippocampus and these activated engrams were used to implant false memories in the mice’s brains.
It was demonstrated that the optogenetic reactivation of memory engram bearing cells was not only sufficient for the behavioral recall of that memory, but could also serve as a conditioned stimulus for the formation of an associative memory. The MIT team is now planning further studies of how memories can be distorted in the brain.
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
Researchers at the Massachusetts Institute of Technology make glucose powered bio-electronics a reality. They have developed a fuel cell that runs on glucose for powering highly efficient brain implants of the future that can help paralyzed patients move their arms and legs again. The fuel cell strips electrons from glucose molecules to create a small electric current.
The researchers fabricated the fuel cell on a silicon chip, allowing it to be integrated with other circuits that would be needed for a brain implant. The glucose fuel cell, when combined with such ultra-low-power electronics, can enable brain implants or other implants to be completely self-powered. Thus making brain glucose as a new energy source for future medical implants.
Rapoport BI, Kedzierski JT, & Sarpeshkar R (2012). A glucose fuel cell for implantable brain-machine interfaces. PloS one, 7 (6) PMID: 22719888
DNA consists of regions called exons, which code for the synthesis of proteins, interspersed with noncoding regions called introns. Being able to predict the different regions in a new and unannotated genome is one of the biggest challenges facing biologists today. Researchers at the Indian Institute of Technology Delhi have used techniques from information theory to identify DNA introns and exons an order of magnitude faster than previously developed methods. The researchers were able to achieve this breakthrough in speed by looking at how electrical charges are distributed in the DNA nucleotide bases. This distribution, known as the dipole moment, affects the stability, solubility, melting point, and other physio-chemical properties of DNA that have been used in the past to distinguish exons and introns.
The research team computed the “superinformation,” or a measure of the randomness of the randomness, for the angles of the dipole moments in a sequence of nucleotides. For both double- and single-strand forms of DNA, the superinformation of the introns was significantly higher than for the exons. Scientists can use information about the coding and noncoding regions of DNA to better understand the human genome, potentially helping to predict how cancer and other diseases linked to DNA develop.
Ramakrishnan, N., & Bose, R. (2012). Dipole entropy based techniques for segmentation of introns and exons in DNA Applied Physics Letters, 101 (8) DOI: 10.1063/1.4747205