Zebrafish vision: A specialised retinal area for prey capture? (2017)
The successful student will spend 2 years at the University of Sussex supervised by Dr Baden and 2 years at the Hong Kong University of Science and Technology (HKUST) supervised by Professor Semmelhack. Zebrafish are a key vertebrate model for vision research. Their transparent early life stages, powerful genetic access and large array of well-studied visual behaviours means that circuits underlying specific functions can be studied at depth and at several levels, from the retina to the brain leading to behaviour. One particularly interesting behaviour is prey capture. Both larval and adult zebrafish rely on their sense of vision to capture their live food, which initially includes single celled organisms (paramecia) and later extends to insects and other small animals that fall into the water from overhanging shrubbery. Building on early anatomical studies, we have recently identified an area of the ventral retina that appears to harbour a high density of cone photoreceptors, much akin to the more well-known "area centralis" of carnivorous mammals such as cats or dogs. In the live fish, the identified retinal domain appears to project to a point in probably binocular visual space just above and in front of the animal. In agreement, preliminary data indicates that larval zebrafish tend to position themselves just beneath and behind prospective prey immediately before they strike - as such, the position of this presumptive area centralis would be appropriate to support prey capture.
Specific Aims and Methods of the project
1) The retinal basis of the zebrafish area centralis. We will functionally characterise its retinal neurons using in vivo 2-photon population imaging during visual stimulation to probe for any functional specialisations and will use simple computational models to explore the consequences of these.
2) Role of the area centralis during prey capture. We will dynamically map the retinal projective field into visual space based on behavioural experiments monitoring eye and head movements. This will also probe how and to what extent animals use eye and body movements to position the prey on this region of the retina.
3) Central processing of area centralis inputs. We will use in vivo 2-photon imaging to identify central neurons that respond to stimuli in the region of visual space corresponding to the area centralis, and subsequently probe their role in driving prey capture using optogenetics, ablation or genetic silencing techniques.
What you get
The scholarship covers full fees and an annual stipend at RCUK rates for 4 years, 2017-18 stipend will be £14,553
Type of award
Postgraduate Research
Eligibility
A first- or upper second-class undergraduate honours degree in a subject relevant to your chosen area of research. Applicants will be required to have IELTS 6.5, with not less than 6.0 in each section.
Deadline
2 May 2017 23:59How to apply
Please submit a formal application using our online application system at http://www.sussex.ac.uk/study/pg/applying/ including a CV, statement of interest and names of two academic referees. On the application system select PhD Neuroscience as the programme of study. Please ensure you include the project title and Supervisor's name with your statement of interest on the application form.
Sponsors
Distribution between HKUST and Sussex:
Retinal imaging and computational modelling will be mainly performed in the lab of Tom Baden at Sussex www.badenlab.org while behavioural experiments as well as brain imaging and ablation studies will be mainly performed in the lab of Julie Semmelhack at HKUST http://life-sci.ust.hk/faculty/Dr.J.Semmelhack/
Example timeline:
Year 1: Sussex. Map retinal extent of area centralis in zebrafish using confocal and 2-photon imaging. Probe functional properties of key retinal neurons of this retinal domain including retinal ganglion cells and bipolar cells.
Year 2: Sussex. Continue functional survey and develop simple computational framework to explore the consequences any found specialisations for visual coding.
Year 3: HKUST. Record prey capture behaviour, analyse eye and body angles to asses positioning of prey on retina.
Year 4: HKUST. Functional imaging to identify and manipulate neurons in visual brain areas that respond to area centralis stimulation.
Contact us
Who to contact for further details
Dr Thomas Baden (Sussex Neuroscience) T.Baden@sussex.ac.uk
Professor Julie Semmelhack (HKUST) jsemmelhack@ust.hk
Timetable
Tuesday 2nd May - deadline to apply
Friday 26th May - all applicants will be notified regarding the outcome of their application
Availability
At level(s):
PG (research)
Application deadline:
2 May 2017 23:59 (GMT)
the deadline has now expired