Discovery could hold the key to super-sensory hearing

A bush cricket

The discovery of a previously unidentified hearing organ in the South American bush crickets’ ear could pave the way for technological advancements in bio-inspired acoustic sensors research, including medical imaging and hearing aid development.
Researchers from the University of Lincoln and University of Bristol discovered the missing piece of the jigsaw in the understanding of the process of energy transformation in the ‘unconventional’ ears of the bushcrickets (or katydids).
Bushcrickets have four tympana (or ear drums) – two on each foreleg; but until now it has been unknown how the various organs connect in order for the insect to hear. As the tympana (a membrane which vibrates in reaction to sound) does not directly connect with the mechanoreceptors (sensory receptors), it was a mystery how sound was transmitted from air to the mechano-sensory cells.
Sponsored by the Human Frontiers Science Program (HFSP), the research was developed in the lab of Professor Daniel Robert, a Royal Society Fellow at the University of Bristol. Dr Fernando Montealegre-Z, who is now at the University of Lincoln’s School of Life Sciences, discovered a newly identified organ while carrying out research into how the bushcricket tubing system in the ear transports sound. The research focussed on the bushcricket Copiphora gorgonensis, a neotropical species from the National Park Gorgona in Colombia, an island in the Pacific. Results suggest that the bushcricket ear operates in a manner analogous to that of mammals. A paper detailing this remarkable new breakthrough is published today in the journal, Science.
Dr Montealegre-Z said: “We discovered a novel structure that constitutes the key element in hearing in these insects, which had not been considered in previous work. The organ is a fluid-filled vesicle, which we have named the ‘Auditory Vesicle’. This hearing organ mediates the process of conversion of acoustic energy (sound waves) to mechanical, hydraulic and electrochemical energy. The integration laser Doppler vibrometry and micro-CT scanning allowed us to identify the auditory vesicle and to conclude that the process relies on a tympanal lever system analogous to the mammalian ossicles. This serves to transmit air-borne vibrations to the fluid (the auditory vesicle), and also on the mechanoreceptors. Therefore the bushcricket ear performs the crucial stage of air to liquid impedance conversion and amplification just as in a mammal’s ear.”
In mammals, hearing relies on three canonical processing stages: an eardrum collecting sound, a middle ear impedance converter and a cochlear frequency analyser. The katydid ear performs these steps in the hearing process, something previously unknown in insects. The discovery of the impedance conversion and amplification mechanisms is a huge step forward in understanding the mechanisms of hearing processes in insects. This level of sophistication, sensitivity and functionality of insect hearing could be transferred into engineered bio-inspired systems. For instance, the ears of some bushcricket species are remarkably sensitive and can detect extreme ultrasonic signals (>130 kHz) at long distances. Such performance and sensitivity would have the potential to inspire engineers in the design and construction of acoustic sensors and actuators.
Dr Montealegre-Z plans to further his research to study the ears of species of the genus Arachnoscelis which use extreme ultrasonics (130 – 150kHz) in order to find out how bushcrickets are able to hear each other’s high pitched sounds from long distances.
He said: “These results were obtained on a single species, C. gorgonensis, which uses moderate ultrasonic frequencies of 23kHz. However, we have measured other species and have discovered a bushcricket species in the rainforests of South America, which emits sounds at 150kHz. Sounds at these frequencies suffer excess attenuation and would not transmit far in a rainforest environment, therefore limiting long-range communication. Yet they manage to listen to one another from far greater distances. We don’t know how they do it, but we do think this sensitivity comes, in part, from the Auditory Vesicle. The University of Lincoln has an excellent team able to continue with this research, while also collaborating with partners at other universities. These findings change our views on insect hearing and open the way for designing ultrasensitive bio-inspired sensors.”
Professor Daniel Robert is one of four academics at the University of Bristol’s School of Biological Sciences who were part of the research team.
He said: “The ears of this bushcricket are teaching us that complex hearing mechanisms can take place in very small ears. As such we are learning how evolution has come up with very small, efficient and sophisticated microphones. We now have to learn how to make one like this.”
Dr Montealegre-Z is planning field research to study katydids in their natural environment in Colombia (Natural National Park Gorgona) with colleagues from the universities of Graz in Austria, Bristol and Strathclyde. Funded by a National Geographic grant the study will entail connecting special electrodes to the katydid sensory system, which will then allow the scientists to hear the same sounds as the insects.
Dr James Windmill, from the Centre for Ultrasonic Engineering in the University of Strathclyde’s Department of Electronic and Electrical Engineering, said: “Dr Montealegre’s findings will make a valuable contribution to our search for the next generation of ultrasonic engineering technologies. By improving our understanding of insect hearing and sensory systems, we can incorporate new ideas and techniques into a wide range of technologies, including hearing aids, biomedical imaging systems for hospitals, and ultrasonic non-destructive evaluation to assess the structural integrity of buildings and bridges. I look forward to working with Dr Montealegre and colleagues on the next stage of this important research, bringing together bioscience and engineering to create the bio-inspired sensors of the future.”
The study was supported by the HFSP, Biotechnology and Biological Sciences Research Council (BBSRC), Royal Society of London and the UK-India Education and Research Initiative.

Read the paper here: http://www.sciencemag.org/content/338/6109/968

Multi-million pound science and innovation park announced

Lincoln is to become home to some of the finest scientific minds and most innovative high-tech businesses in the UK, thanks to ambitious plans announced today (Thursday 2nd August 2012).

The University of Lincoln and Lincolnshire Co-operative are joining forces to transform a disused 10-acre site in the heart of the city into a world-class science and innovation park.

The multi-million pound project will see a substantial plot of land and buildings on Green Lane (off Tritton Road) becoming a hub of science and technology expertise and home to a mix of university and commercial enterprises in what is a first for the city.

Part of the development of the park, which is owned by Lincolnshire Co-op, is the University’s plan to locate its School of Life Sciences and the proposed new School of Pharmacy in Becor House.

Significant refurbishment of this landmark building by the University will create state-of-the-art laboratories and teaching spaces for disciplines such as biology, biomedical science and bioveterinary science.

In addition, the University as the anchor tenant would create spin-out businesses and attract onto the site high-tech companies in the fields of pharmaceutical science and biotechnology as well as other areas of scientific and industrial development and engineering.

Professor Mary Stuart, Vice Chancellor of the University, said: “This is a tremendously exciting step for the University as we strengthen and grow our science provision, and one which will bring massive benefits to the city in terms of employment and inward investment.

“Highly skilled professionals who have previously looked outside Lincolnshire for career opportunities will be attracted to the area or be encouraged to stay, and the potential to bring in new investors and high-tech businesses to boost the local economy is enormous.

“Our shared vision with Lincolnshire Co-operative is to build a vibrant and successful community of knowledge creators and businesses, working together creatively to promote enterprise, employment, investment and education in Lincoln.”

Co-locating academia and commerce will bring benefits for both, and investment in the site by the University and the Co-op could reach £14 million.

There is a range of similar successful projects nationally. Cambridge Science Park was founded in 1970 by Trinity College, Cambridge, and hosts businesses such as Toshiba and Bayer CropScience Ltd.  Biopark, near Welwyn Garden City, features companies working in various fields including the development of oncology drugs, supplying advanced medical equipment and researching new innovations in electronics.

Chief Executive of Lincolnshire Co-op Ursula Lidbetter said: “We think there’s a huge opportunity to turn this underused site into a stimulating place to work and study. It’s an ideal location for a science park as it’s so close to the University campus and Lincoln city centre.

“As a co-operative, we share our profits with our members and their communities and we want to be involved with developments like this which will bring employment opportunities and investment to the city.

“We also run 47 pharmacies across our trading area and are keen to support the proposed new School of Pharmacy. We’ll be able to offer placements to students during their courses, and then potentially job opportunities. Our pharmacists will be able to take advantage of the facilities for their professional development.”

Initial work on the complex will be completed by the end of 2013, with between 1,200 and 1,500 science students based there, along with around 100 academic and research staff.

Professor Andrew Hunter, Pro Vice Chancellor for the University’s College of Science, added: “The University is in the process of recruiting more than 20 new high profile life and pharmaceutical scientists who need access to good laboratories and offices. But alongside the academic spaces will be industrial developments and we will be looking for other organisations to partner with, following a similar model to our highly successful engineering collaboration with Siemens.”

Antidepressants can cut cancer risk

Antidepressants commonly prescribed to treat depression and other psychiatric disorders can significantly reduce the chance of developing certain kinds of cancer, according to a recent study by the University of Lincoln’s Dr Tim Bates.

The study, which was conducted in partnership with colleagues from the University of Nottingham and the University of Warwick, examined more than 90,000 patients. The study found that those who were taking tricyclic antidepressants had a significantly lower incidence of colorectal cancer and glioma (a major type of brain tumour) than those who were not – by as much as 64% in the case of glioma and 21% for colorectal cancer.

Human lung cancer cells seen under a microscop Tim Bates
Human lung cancer cells seen under a microscope Tim Bates

The study offers the basis for a new approach to the prevention and treatment of cancer through the development of antimitochondrial drugs which would inhibit the growth of cancer cells, resulting in a form of “cell suicide” known as programmed cell death or apoptosis, without harming normal cells.

Dr Bates said: “Development of drugs that modulate mitochondrial function may seem counter-intuitive as mitochondria provide the majority of the cell’s energy, but as cancer mitochondria are biochemically different from mitochondria in normal non-cancer cells, they represent an Achilles heel. It is likely this will lead to the development of new drug treatments for a variety of conditions including cancer, Alzheimer’s and Diabetes.”