Acoustical nanometre-scale vibrations of live cells detected by a near-field optical setup

External control of the Drosophila melanogaster lifespan by combination of 3D oscillating low-frequency electric and magnetic fields

We demonstrate that the lifespan of Drosophila melanogaster population is controllable by a combination of external three-dimensional oscillating low-frequency electric and magnetic fields (3D OLFEMFs). The lifespan was decreased or increased in dependence of the parameters of the external 3D OLFEMFs. We propose that metabolic processes in D. melanogaster's body are either accelerated (in the case of reduced lifespan) or slowed down (in the case of increased lifespan) in function of 3D OLFEMFs that induce vibrational motions on sub-cellular and larger scales.

Sensitivity maximized near-field scanning optical microscope with dithering sample stage

We developed a new scheme for a higher sensitivity near-field scanning optical microscope (NSOM) by using a dithering sample stage rather than a dithering probe for the constant gap control between probe and sample. In a conventional NSOM, which use tip dithering feedback mechanism, the Q factor drastically decreases from 7783 to 1000 (13%) or even to 100 (1%) because harmonic oscillating characteristic is deteriorated owing to the large change of stiffness and mass of one prong of tuning fork when a probe is attached to it. In our proposed scheme, on the other hand, we use sample dithering feedback mechanism, where the probe is not attached to the tuning fork and the sample is loaded directly onto the surface of dithering tuning fork. Thus, the Q factor does not decrease significantly, from only 7783 to 7480 (96%), because the loaded sample hardly changes the stiffness and mass of tuning fork. Accordingly, gap control between the immobile fiber probe and the dithering sample is performed precisely by detecting the shear force with high sensitivity. Consequently, the extremely high Q factor enables clear observation of graphene sheets with sub-nanometer vertical resolution, which is not possible with a conventional NSOM setup.

Mechano-electrical vibrations of microtubules--link to subcellular morphology

Spontaneous mechanical oscillations were predicted and experimentally proven on almost every level of cellular structure. Besides morphogenetic potential of oscillatory mechanical force, oscillations may drive vibrations of electrically polar structures or these structures themselves may oscillate on their own natural frequencies. Vibrations of electric charge will generate oscillating electric field, role of which in morphogenesis is discussed in this paper. This idea is demonstrated in silico on the conformation of two growing microtubules.

Electromagnetic cellular interactions

Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating.

Protective effect of serotonin derivatives on glucose-induced damage in PC12 rat pheochromocytoma cells

Oxidative damage is believed to be associated with ageing, cancer and several degenerative diseases. Previous reports have shown that safflower-seed extract and its major antioxidant constituents, serotonin hydroxycinnamic amides, possess a powerful free radical-scavenging and antioxidative activity, paying particular attention to atherosclerotic reactive oxygen species (ROS)-related dysfunctions. In the present report, we examined a still unknown cell-based mechanism of serotonin derivatives against ROS-related neuronal damage, phenomena that represent a crucial event in neurodegenerative diseases. Serotonin derivatives N-(p-coumaroyl)serotonin and N-feruloylserotonin exerted a protective effect on high glucose-induced cell death, inhibited the activation of caspase-3 which represents the last and crucial step within the cascade of events leading to apoptosis, and inhibited the overproduction of the mitochondrial superoxide, which represents the most dangerous radical produced by hyperglycaemia, by acting as scavengers of the superoxide radical. In addition, serotonin derivative concentration inside the cells and inside the mitochondria was increased in a time-dependent manner. Since recent studies support the assertion that mitochondrial dysfunctions related to oxidative damage are the major contributors to neurodegenerative diseases, these preliminary cell-based results identify a mitochondria-targeted antioxidant property of serotonin derivatives that could represent a novel therapeutic approach against the neuronal disorders and complications related to ROS.