Archive

A conspicuous ability of the mammalian brain to integrate and process huge amount of spatial, visual and temporal stimuli is a result of its enormous structural complexity functioning in an integrated way as a whole. Here we review recent achievements in the understanding of brain structure and function. A traditional view on the brain as a network of neurons has been extended to the more complicated structure including overlapping and interacting networks of neurons and glial cells. We discuss artificial versus natural neural networks and consider a concept of attractor networks. Moreover, we speculate that each neuron can have an intracellular network on a genetic level, based and functioning on the principle of artificial intelligence. Hence, we speculate that mammalian brain is, in fact, a network of networks. We review different aspects of this structure and propose that the study of brain can be successful only if we utilize the concepts recently developed in nonlinear dynamics: the concept of integrated information, emergence of collective dynamics and taking account of unexpected behavior and regimes due to nonlinearity. Additionally, we discuss perspectives of medical applications to be developed following this research direction.

Classically, the central nervous system (CNS) was considered to contain neurons and three main types of glial cells - astrocytes, oligodendrocytes, and microglia.  Now, it has been clearly established that NG2-glia are a fourth glial cell type that are defined by their expression of the NG2 chondroitin sulfate proteoglycan (Cspg4).  NG2-glia are also known as oligodendrocyte precursor cells (OPCs) and express the alpha receptor for platelet-derived growth factor (Pdgfra) as well as other oligodendrocyte lineage markers. NG2-glia are most numerous during CNS development when they are responsible for massive generation of oligodendrocytes, the myelin-forming cells of the CNS. A significant population of NG2-glia persist in the adult CNS, where they generate oligodendrocytes throughout life. A unique feature of NG2-glia is that they receive synaptic inputs from neurons and are able to respond rapidly to neurotransmission via their specific ion channel and receptor profiles. Moreover, synaptic and neuronal integrity depend on NG2-glia. Notably, concomitant disruption of NG2-glia, myelin and neurotransmission are key features of many neuropathologies, including Multiple Sclerosis and Alzheimer’s disease (AD). The fact that neurotransmission both regulates and is reliant on NG2-glia and myelin raises the ‘chicken and egg’ question of what comes first – disruption of NG2-glia/myelin or synapses/neurons. It is more useful to think of neurons, NG2-glia and oligodendrocytes/myelin as being functionally integrated and interdependent units, whereby disruption of any one can result in a vicious cycle with potentially devastating effects on CNS function.

Download PDF (Full Text)

The effect of 2-aminoethyl diphenylborinate (2-APB), a commonly used drug to modulate inositol-1,4,5-triphosphate (IP3) receptors and transient receptor potential (TRP) channels, on GABAA receptor-mediated currents was studied in neurons from the medial preoptic nucleus (MPN) of rat. 2-APB gradually and reversibly reduced the currents evoked by GABA but had no effect on the currents evoked by glycine. The blocking effect was not mediated by alterations in intracellular calcium concentration and showed a concentration dependence with half maximal effect at ~50 µM 2-APB, for currents evoked by 100 µM, as well as by 1.0 mM GABA, suggesting that 2-APB is not competing with GABA for its binding site at the GABAA receptor. Thus, the present study describes a novel pharmacological property of 2-APB as a non-competitive blocker of GABAA receptors and calls for caution in the interpretation of the results where 2-APB is used to affect IP3 receptors or TRP channels.

Stem cells research has passed a long and exciting way from the discovery to clinical applications. Every year more-and-more scientific reports and solid research breakthroughs are published in this fascinating field making it difficult to follow after new discoveries and cover the history. In the current review we overviewed history of stem cells research starting from the discovery and ending with the current state-of-art. We discussed obstacles and future perspectives of the cell-based therapy, with a special focus made on protection and regeneration of the lost functions after injury/degeneration of adult central nervous system.