The slime mould Physarum polycephalum is a single-celled organism without an obvious nervous system. Nevertheless, it has recently been shown to use an external spatial memory to navigate. When it explores an environment, it leaves behind a trail of extracellular slime, which if it encounters later, it strongly avoids. This response ensures that the organism does not revisit areas that it has already investigated. The avoidance behaviour is also a choice because when no previously unexplored territory is available, the slime mould no longer avoids the slime. In essence then it possesses an externalised memory, which because it relies on feedback from chemicals, maybe a precursor to our own. Here the tracks left behind by the slime mould, or that is its memory, have been revealed using a DIC microscope. The spaces occupied by its filaments can be clearly seen surrounded by small crystals which must represent its memory
The web is built as a trap, and even after the spider has abandoned it, it still retains this function. However, in this case, instead of catching insects it serves as a trap for much smaller prey. Huge volumes of air pass through its structure, and thus it acts as a kind of passive filter feeder concentrating biological information in the form of human skin cells, fabric microfibers, and other dander. We like comets, leave a trail of trail of debris as we move through any environment, and this normally invisible tail, of what we are made of, or what we chose to wear, is captured by the web so that its threads hold a microscopic narrative of our past actions. The microscope reveals these many stories.
Cytoplasmic streaming in the slime mould Physarum polycephalum as imaged through C-MOULDS new DIC Microscope. More to follow…………
Paul Ehrlich’ made countless contributions to science, in fields as diverse as histology, haematology, immunology, oncology, microbiology and pharmacology. In the course of his investigations Ehrlich came across methylene blue, which he regarded as particularly suitable dye for staining bacteria. Here I have drawn upon Ehrlich’s early studies on staining bacteria and developed a simple off-the shelf/ DIYBio-staining procedure for bacteria and human cells. It is based on methylene blue which is readily available as a “fish medicine”. The brand I used here is King British Methylene Blue. It works very well as it comes in the bottle, and without the need for any messy preparation. Here I have stained saliva from my own mouth and the stain has revealed my own cells, their nuclei, and the normal bacterial flora of my mouth
More crystals as imaged through C-MOULD’s new DIC microscope
More crystals as viewed usingC-MOULD’s new Nikon Eclipse Ni-U Differential Interference Contrast Microscope.