MARK YOUR CALENDAR
NEXT MEETING:
Date: Saturday 14 March, 2026
Venue: Zara’s House - 1a Hill Street, Jesmond NSW
Time: 10.00 to 12 Midday
Guest: Prof Jose Antonio Lopez Escamez,Professor of Meniere’s and Neurosciences at the Kolling Institute, University of Sydney
in Australia
Report from 6 December: Newcastle regional support Group
Summary of visit from Professor Alan Brichta and Assoc Prof Rebecca Lim from the University of Newcastle.
Megan James, who is the Coordinator of the Newcastle Region Meniere’s Support Group reported
on her last meeting 6 December as follows:
We had a great session on Sat 6th Dec at Jesmond, with visit from Professor Alan Brichta and Assoc
Prof Rebecca Lim from the University of Newcastle. Such passion and enthusiasm for the ‘exquisite’
vestibular system – very informative and entertaining. Thank you for your gift of hope!
Both Alan and Rebecca recognised they are part of a team of scientists undertaking this research. I
have collated the following notes from the session.
Alan presented on the vestibular system, explaining its structure and function. He described the
semicircular canals, saccule, and utricle, as well as the fluid dynamics and hair cells involved in
balance perception. At the base of each of the three semicircular canals is a bulb-shaped swelling
called the ampulla, which houses hair cells, thousands of them. The hair bundles bend as a result of
motion, and an electrical signal gets transmitted to the central nervous system. In other words, the
hair cell converts mechanical motion into electrical signals.
“Balance is one of our first senses to develop. When looking at embryos developing, it's the balance
organs that start developing long before the other senses and hearing organs. The way we keep our
balance, is exactly the same way as a mouse keeps its balance, and nearly all other animals”.
Recognise two types of hair cells in inner ear vestibular system:
• Type I (vase shaped) and Type II (cigar shaped).
• Alan created the analogy of the Type 1 being a Ferrari, and the Type II being a SUV.
• Type II, SUV - generic hair cell, found in all animals; frogs, birds, amphibians
• Type I, Ferrari - only found in reptiles, birds, and mammals – habitat for the most part on
land, with head movements in air (much quicker than head movements in water).
• Two types - one that does the average stuff (Type II), and one that responds to very quick
head movements (Type I)
Type 1 hair cell ending is engulfed or gloved by a nerve called the calyx. “We've got this special
edition (hair cell) that has this unusual calyx, and we think that calyx is there to get speed”.
Experimentation has found that when voltages change, small gateways open up in the in the calyx.
These gateways allow solutions like potassium and sodium in or out of the cell. This is what happens
when we move our head. Alan showed activation curves from experimentation, initially on isolated
hair cells, with further work completed on the intact system. It was found that on activation, a
change in concentration of potassium occurs as the fluid moves to fill the gap between the hair cell
and the nerve (calyx) – a very fast and “exquisitely sensitive system”. Small increases in the size of
this gap results in loss of sensitivity of the balance system.
“You've got high potassium on top (endolymph), you've got low potassium at the bottom
(perilymph). Now, when you move your head, you move the hair bundle. What that does, is allow the
potassium to go into the cell”.In the last 10 years, scientists have found that potassium is a major player in the vestibular system.
Scientists in Chicago are undertaking mathematical modelling to be able to play around with these
aspects of the system.
Rebecca
In collaboration with Rob Eisenberg, Rebecca been collecting tissue from people with vestibular
schwannoma – a slow-growing benign, (non-cancerous) Schwann cell tumour. Vestibular
Schwannoma affects about 4 in 100,000 people. For most people, these are spontaneous, do not
appear to be a genetic, and commonly occur in a single ear only. However, in 5% of people, there is a
genetic component, and it is then called neurofibromatosis. Nerves carry balance and hearing
information from the inner ear to the brain. These nerves are surrounded by Schwann cells, like
insulating cables. The nerves travel through a small hole in the skull to the brain.
“When the tumour, grows it begins to compress the both the vestibular nerve carrying the balance
information, and the auditory nerve carrying the hearing information. It's a tiny little space, so
there's nowhere for it to go once those nerves get compressed”.
Symptoms include: Hearing loss, tinnitus, pressure in the ear, dizziness, and balance problems
(similar symptoms to Meniere’s Disease). Tumours can get large and can be very debilitating, and
eventually life-threatening if not addressed. Treatment options include wait and see, radiotherapy,
and surgical removal. Presently no drugs possible to treat the condition. Rebecca and a team have
been working to identify a drug that may be used to slow down or stop the tumour growth. Testing
is performed by identifying how many schwannoma cells are alive after the drug treatment. After
much work, Rebecca reported an inhibitor has been identified that has only 7% of cells surviving
after three days. This drug is already approved by the TGA for cancer treatment. Rebecca and the
team are seeking funding to take the drug to Phase Two clinical trials. Ideally, drug treatment can be
used to treat the schwannoma with minimal long-term impact on the balance organs.
“Hopefully next time, I can come back and tell you that we are through to Phase Two and that we're
helping people with their schwannomas”.
