Ever wondered how spiders work out where they have trapped a fly in their web? Researchers in Oregon have created a big artificial spider’s web to try and understand how orb-weaving spiders sense vibrations caused by trapped prey. At the centre of the web sits an artificial 8-legged spider which is unable to move but acts as a detection method for vibrations. Their original hypothesis was that the spider would be able to sense the strand vibrated by the prey more so than the others. They actually revealed that vibration patterns were far more complex leading to several strands vibrating and some regions in the web where the shaking completely vanishes. This is thought to be dependent on factors such as frequency, and potentially the type of insect caught in the web. Therefore, spiders must be aware of how the vibration frequency corresponds to the structure of their web so that they move in the right direction.
Forgetting in Order to Remember
As it turns out, sometimes it is useful to forget things! A neural pathway that is responsible for purposefully removing related memories while creating new ones has been discovered, and this is thought to help with the recall of information. The creation of memories occurs in an area of the brain called the hippocampus, as does their retrieval. Within the hippocampus, a sub-region named the dentate gyrus is responsible for transferring sensory input information from upstream to the hippocampus. To understand the mechanism of this, a European research group trained genetically engineered mice to associate mild electric shocks with particular sounds. If they inhibited the activity of the dentate gyrus during the learning process, these connections were not formed. This led to the identification of a receptor found only in the detante gyrus, Npy1. When this receptor is activated pharmacologically in mice, it induces memory loss associated with learning as shown in other work. It is thought that this could allow for novel therapeutic development for conditions such as post-traumatic stress disorder (PTSD).
Rejuvenated Retinal Cells
A new study has challenged the traditional neuroscience dogma that neurons are unable to grow and divide. Researchers looking at several inherited forms of blindness in canines have shown that there is a brief period where photoreceptor cells in the retina regenerate. The cells were able to continue dividing at different stages in the various diseases and this was shown by using chemical labels for markers of cells undergoing division. The temporary period of rejuvenation is unfortunately followed by a period of cell death and degeneration in these diseases, however this seems to be a distinctly different population of cells. It is hoped this work could provide a basis for developing a therapy that could interfere with retinal degeneration in inherited blindness by identifying the genes involved in ‘turning cell division on’ in retinal cells.
Written by: Rosemary Pike