Jonathan Ashmore

Last updated
Jonathan Ashmore
Professor Jonathan Ashmore.jpg
Jonathan Ashmore at the Royal Society in 2017
Born
Jonathan Felix Ashmore

1948 (age 7576)
Education Westminster School [1]
Alma mater University of Sussex (BSc)
Imperial College London (PhD)
University College London (MSc) [2]
Awards Croonian Lecture (2017) [3]
Scientific career
Fields Hearing [4] [5]
Biophysics [6]
Institutions University College London
University of Bristol
International Centre for Theoretical Physics
Thesis Aspects of quantum field theory  (1972)
Doctoral advisor Tom Kibble [7]
Other academic advisors
Doctoral studentsDan Jagger [9]
Website inner-ear.org

Jonathan Felix Ashmore FRS FMedSci FRSB (born 1948) [1] is a British physicist and Bernard Katz Professor of Biophysics at University College London. [10]

Contents

Early life and education

Ashmore is the son of renowned theatre director and actor Peter Ashmore and distinguished actress Rosalie Crutchley. [11]

Educated at Westminster School [1] as a Queen's Scholar, he studied mathematics and physics at the University of Sussex [2] followed by a PhD in theoretical physics in 1971 supervised by Tom Kibble at Imperial College London where his research investigated quantum field theory. [7]

Career and research

After a short postdoctoral research fellowship supervised by Abdus Salam [8] at the International Centre for Theoretical Physics in Trieste, Italy he retrained as a physiologist at UCL, gaining a Master of Science degree in 1974 [2] which led to work with Paul Fatt and Gertrude Falk [12] between 1974 and 1977 in the Biophysics Department.

Ashmore was appointed a Lecturer in Physiology at the University of Bristol in 1983 and promoted to Reader in 1988, before moving back to UCL in 1993. [8] [2]

Ashmore has worked on dissecting the cellular mechanisms of hearing by studying the organ of Corti in the mammalian cochlea [13] especially the guinea pig (Cavia porcellus). [14] [15] This structure in the inner ear increases the selectivity and sensitivity of our hearing through an in-built cochlear amplifier. [16] He showed that specialised cells known as outer hair cells are responsible for this unique function. [16] [17] [18]

In response to sound, outer hair cells lengthen then shorten through a process controlled and powered by the flow of electrically charged molecules such as potassium ions. [19] This contraction propagates and amplifies sound, and he was the first to capture it on film during his Rock Around the Clock Hair Cell video. [10] [16]

His work has combined biophysical methods – including the patch clamp technique usually applied to membrane proteins – with confocal microscopy imaging and computational modelling to expand our knowledge of hearing at the molecular and cellular level. His findings are helping to unravel the nature and origins of hearing-related conditions like deafness and tinnitus. [3] [16]

His research has been funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the Medical Research Council (MRC) [20] and he has supervised several doctoral students to completion including Dan Jagger. [9]

Awards and honours

Ashmore was elected a Fellow of the Royal Society (FRS) in 1996 [1] and gave their Croonian Lecture in 2017 on the neuroscience of deafness. [3] He is also an elected Fellow of the Academy of Medical Sciences (FMedSci), a Fellow of the Royal Society of Biology (FRSB) [1] and a member of both the Association for Research in Otolaryngology and The Biophysical Society. [21]

Ashmore is Faculty of 1000 section head for Sensory Systems [21] and a trustee for the Hearing Research Trust.[ citation needed ] He served as president of The Physiological Society from 2012 to 2014. [8]

Personal life

Aged seven, Ashmore played Joe in the 1955 film A Kid for Two Farthings , adapted from the novel by Wolf Mankowitz. [22] Through his mother, Ashmore is descended from the 1st Earl of Leicester and his second wife, Lady Anne Amelia Keppel, a descendant of Charles II of England.

Related Research Articles

<span class="mw-page-title-main">Cochlea</span> Snail-shaped part of inner ear involved in hearing

The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the organ of Corti, the sensory organ of hearing, which is distributed along the partition separating the fluid chambers in the coiled tapered tube of the cochlea.

<span class="mw-page-title-main">Basilar membrane</span> Inner ear structure

The basilar membrane is a stiff structural element within the cochlea of the inner ear which separates two liquid-filled tubes that run along the coil of the cochlea, the scala media and the scala tympani. The basilar membrane moves up and down in response to incoming sound waves, which are converted to traveling waves on the basilar membrane.

<span class="mw-page-title-main">Organ of Corti</span> Receptor organ for hearing

The organ of Corti, or spiral organ, is the receptor organ for hearing and is located in the mammalian cochlea. This highly varied strip of epithelial cells allows for transduction of auditory signals into nerve impulses' action potential. Transduction occurs through vibrations of structures in the inner ear causing displacement of cochlear fluid and movement of hair cells at the organ of Corti to produce electrochemical signals.

<span class="mw-page-title-main">Hair cell</span> Auditory sensory receptor nerve cells

Hair cells are the sensory receptors of both the auditory system and the vestibular system in the ears of all vertebrates, and in the lateral line organ of fishes. Through mechanotransduction, hair cells detect movement in their environment.

<span class="mw-page-title-main">Endolymph</span> Inner ear fluid

Endolymph is the fluid contained in the membranous labyrinth of the inner ear. The major cation in endolymph is potassium, with the values of sodium and potassium concentration in the endolymph being 0.91 mM and 154 mM, respectively. It is also called Scarpa's fluid, after Antonio Scarpa.

<span class="mw-page-title-main">Perilymph</span> Extracellular fluid located within the inner ear

Perilymph is an extracellular fluid located within the inner ear. It is found within the scala tympani and scala vestibuli of the cochlea. The ionic composition of perilymph is comparable to that of plasma and cerebrospinal fluid. The major cation in perilymph is sodium, with the values of sodium and potassium concentration in the perilymph being 138 mM and 6.9 mM, respectively. It is also named Cotunnius' liquid and liquor cotunnii for Domenico Cotugno.

<span class="mw-page-title-main">Prestin</span> Protein-coding gene in the species Homo sapiens

Prestin is a protein that is critical to sensitive hearing in mammals. It is encoded by the SLC26A5 gene.

<span class="mw-page-title-main">Superior olivary complex</span> Collection of brainstem nuclei related to hearing

The superior olivary complex (SOC) or superior olive is a collection of brainstem nuclei that is located in pons, functions in multiple aspects of hearing and is an important component of the ascending and descending auditory pathways of the auditory system. The SOC is intimately related to the trapezoid body: most of the cell groups of the SOC are dorsal to this axon bundle while a number of cell groups are embedded in the trapezoid body. Overall, the SOC displays a significant interspecies variation, being largest in bats and rodents and smaller in primates.

The olivocochlear system is a component of the auditory system involved with the descending control of the cochlea. Its nerve fibres, the olivocochlear bundle (OCB), form part of the vestibulocochlear nerve, and project from the superior olivary complex in the brainstem (pons) to the cochlea.

The cochlear amplifier is a positive feedback mechanism within the cochlea that provides acute sensitivity in the mammalian auditory system. The main component of the cochlear amplifier is the outer hair cell (OHC) which increases the amplitude and frequency selectivity of sound vibrations using electromechanical feedback.

Auditory fatigue is defined as a temporary loss of hearing after exposure to sound. This results in a temporary shift of the auditory threshold known as a temporary threshold shift (TTS). The damage can become permanent if sufficient recovery time is not allowed before continued sound exposure. When the hearing loss is rooted from a traumatic occurrence, it may be classified as noise-induced hearing loss, or NIHL.

<span class="mw-page-title-main">Annette Dolphin</span> Professor of Pharmacology

Annette Catherine Dolphin is a Professor of Pharmacology in the Department of Neuroscience, Physiology and Pharmacology at University College London (UCL).

Peter Dallos is the John Evans Professor of Neuroscience Emeritus, Professor Emeritus of Audiology, Biomedical Engineering and Otolaryngology at Northwestern University. His research pertained to the neurobiology, biophysics and molecular biology of the cochlea. This work provided the basis for the present understanding of the role of outer hair cells in hearing, that of providing amplification in the cochlea. After his retirement in 2012, he became a professional sculptor.

<span class="mw-page-title-main">Maria Fitzgerald</span> British neuroscientist (born 1953)

Maria Fitzgerald is a professor in the Department of Neuroscience at University College London.

<span class="mw-page-title-main">Anne Ridley</span> Professor of Cell Biology

Anne Jacqueline Ridley is professor of Cell Biology and Head of School for Cellular and Molecular Medicine at the University of Bristol. She was previously a professor at King's College London.

<span class="mw-page-title-main">Andrew King (neurophysiologist)</span> British neurophysiologist and professor

Andrew John King is a Professor of Neurophysiology and Wellcome Trust Principal Research Fellow in the Department of Physiology, Anatomy and Genetics at the University of Oxford and a Fellow of Merton College, Oxford.

<span class="mw-page-title-main">Charles Swanton</span> British physician scientist

(Robert) Charles Swanton is British physician scientist specialising in oncology and cancer research. Swanton is a senior group leader at London's Francis Crick Institute, Royal Society Napier Professor in Cancer and thoracic medical oncologist at University College London and University College London Hospitals, co-director of the Cancer Research UK (CRUK) Lung Cancer Centre of Excellence, and Chief Clinician of Cancer Research UK.

<span class="mw-page-title-main">Hensen's cell</span>

Hensen's cells are a layer of tall supporting cells around the outer hair cells (OHC) in the organ of Corti in the cochlea. Their appearance are upper part wide with lower part narrow, column like cells. One significant morphologic feature of Hensen's cells is the lipid droplets, which are most noticeable at the third and forth turns of the cochlear, the lipid droplets are thought to have association with the auditory process because they are parallel to the innervation. One significant structure found among the Hensen's cells and the hair cells are the gap junctions, which are made of connexins which serve important functions in distribution and connection between cells; the gap junctions enable long distance electrical communication.

Caetano Maria Pacheco Pais dos Reis e Sousa is a senior group leader at the Francis Crick Institute and a professor of Immunology at Imperial College London.

Anant B. Parekh is professor of Physiology at the University of Oxford and a Fellow of Merton College, Oxford.

References

  1. 1 2 3 4 5 "ASHMORE, Prof. Jonathan Felix" . Who's Who . Vol. 2017 (online Oxford University Press  ed.). Oxford: A & C Black.(Subscription or UK public library membership required.)
  2. 1 2 3 4 ORCID   0000-0001-6522-3692
  3. 1 2 3 Ashmore, Jonathan (2017) Now you hear it, now you don’t: the neuroscience of deafness on YouTube
  4. Jonathan Ashmore publications indexed by Google Scholar OOjs UI icon edit-ltr-progressive.svg
  5. Jonathan Ashmore publications indexed by the Scopus bibliographic database. (subscription required)
  6. Jonathan Ashmore publications from Europe PubMed Central
  7. 1 2 Ashmore, Jonathan Felix (1972). Aspects of quantum field theory. ethos.bl.uk (PhD thesis). University of London. hdl:10044/1/16203. OCLC   930651621.[ permanent dead link ]
  8. 1 2 3 4 5 Ashmore, Jonathan Felix (2016). "Paul Fatt. 13 January 1924 – 28 September 2014". Biographical Memoirs of Fellows of the Royal Society . 62. London: 167–186. doi: 10.1098/rsbm.2016.0005 . ISSN   0080-4606.
  9. 1 2 Jagger, Daniel James (1996). Modulation of ion channels in outer hair cells from the mammalian cochlea. ethos.bl.uk (PhD thesis). University of Bristol. OCLC   931565011.
  10. 1 2 Anon (2017). "Professor Jonathan Ashmore Lab Page". ucl.ac.uk. University College London. Archived from the original on 2017-04-26. Retrieved 2017-04-25.
  11. Purser, Philip (1997-08-20). "The Director's Cut, Guardian Obituary, Peter Ashmore". The Guardian newspaper . p. 16. Retrieved 2024-04-09.
  12. Anon (2008). "Physiological Society obituary: Gertrude Falk 1925-2008" (PDF). dcscienece.net.
  13. Housley, G. D.; Ashmore, J. F. (1991). "Direct Measurement of the Action of Acetylcholine on Isolated Outer Hair Cells of the Guinea Pig Cochlea". Proceedings of the Royal Society of London B: Biological Sciences. 244 (1310): 161–167. Bibcode:1991RSPSB.244..161H. doi:10.1098/rspb.1991.0065. ISSN   0962-8452. PMID   1679550. S2CID   1950263.
  14. Ashmore, J. F.; Meech, R. W. (1986). "Ionic basis of membrane potential in outer hair cells of guinea pig cochlea". Nature . 322 (6077): 368–371. Bibcode:1986Natur.322..368A. doi:10.1038/322368a0. PMID   2426595. S2CID   4371640. Closed Access logo transparent.svg
  15. Nobili, Renato; Mammano, Fabio; Ashmore, Jonathan (1998). "How well do we understand the cochlea?". Trends in Neurosciences. 21 (4): 159–167. doi:10.1016/s0166-2236(97)01192-2. PMID   9554726. S2CID   15474808. Closed Access logo transparent.svg
  16. 1 2 3 4 Anon (1996). "Professor Jonathan Ashmore FMedSci FRS". royalsociety.org. London: Royal Society. Archived from the original on 2015-11-17. One or more of the preceding sentences incorporates text from the royalsociety.org website where:
    “All text published under the heading 'Biography' on Fellow profile pages is available under Creative Commons Attribution 4.0 International License.” -- "Royal Society Terms, conditions and policies". Archived from the original on 2016-11-11. Retrieved 2016-03-09.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  17. Ashmore, Jonathan Felix (1987). "A fast motile response in guinea-pig outer hair cells: the cellular basis of the cochlear amplifier". The Journal of Physiology . 388 (1): 323–347. doi:10.1113/jphysiol.1987.sp016617. ISSN   1469-7793. PMC   1192551 . PMID   3656195. Open Access logo PLoS transparent.svg
  18. Ashmore, Jonathan (2008). "Cochlear Outer Hair Cell Motility". Physiological Reviews . 88 (1): 173–210. doi:10.1152/physrev.00044.2006. ISSN   0031-9333. PMID   18195086. Open Access logo PLoS transparent.svg
  19. Housley, G D; Ashmore, J F (1992). "Ionic currents of outer hair cells isolated from the guinea-pig cochlea". The Journal of Physiology . 448 (1): 73–98. doi:10.1113/jphysiol.1992.sp019030. ISSN   1469-7793. PMC   1176188 . PMID   1593487. Open Access logo PLoS transparent.svg
  20. Anon (2017). "UK Government Grants awarded to Jonathan Ashmore". gtr.rcuk.ac.uk. Swindon: Research Councils UK. Archived from the original on 2017-10-31.
  21. 1 2 Anon (2011). "Jonathan Ashmore: Section Head in Sensory Systems - F1000Prime". F1000.com. Archived from the original on 2012-04-05. Retrieved 2017-04-25.
  22. Jonathan Ashmore at IMDb

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