How is diverse sensory information encoded within the simple circuitry of the thalamus?

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

The Sox14cre/+ line has enabled us to identify the monosynaptic inputs arriving onto interneurons of the visual thalamus (dLGN-INsox14) using cre-dependent rabies virus tracing (RVCre). Our pilot data has highlighted the potential for dLGN-INsox14 neurons to receive input from multiple retinal ganglion cell (RGC) types; morphologically identified based upon criteria such as dendrite stratification in the internal plexiform layer. This data revealed also a previously unappreciated synaptic input to dLGN-INsox14 neurons from the reticular thalamic nucleus (RTN) that could be the dominant input to dLGN-INsox14 neurons in terms of connectivity. This proposal will study how morphologically identified RGC-types control dLGN-INsox14-mediated inhibition within the thalamus and examine the RTNs influence on dLGN-INsox14 neurons. Following morphological identification of RGC-types we will record from fluorescently labelled dLGN-INsox14 neurons in the Sox14gfp/+ line and use a dynamic-clamp approach to mimic the presence of specific RGC inputs. Paired simultaneous recording between dLGN-INsox14 neurons and relay neurons will help reveal how RGC input from ON, OFF and ON/OFF receptive fields can influence tonic and phasic inhibition. Preliminary data suggests a frequency-dependent switch occurs in the GABA release mechanism that could explain how separation of visual information from distinct RGC-types is maintained within the relatively simple thalamic circuitry. We will deliver channel rhodopsin to the RTN using a modified RVcre technique to specifically activate the RTN input onto dLGN-INsox14 neurons. Finally, we will use pharmacogenetics to silence dLGN-INsox14 neurons during visual stimulation to test a specific hypothesis that a push-pull mechanism operates through the dLGN-INsox14 circuitry to enable de novo reconstruction of the OFF response associated with visual receptive fields.

Who might benefit from this research? The immediate beneficiaries of the work undertaken during this proposal will be the research scientists involved, including the two PIs, two PDRAs and PhD students. Additionally, other research scientists who are involved in similar research in the life sciences as well as the wider academic community and the pharmaceutical/biotechnology industry will benefit from our findings. It also hoped that members of the public will feel sufficiently motivated to engage with the more accessible aspects of this research.
2. How might they benefit from this research? The career progression of the two PIs involved in this research will be enhanced due to the publications resulting from this work. The two PDRAs employed on the grant will become trained in several highly desirable skills that will enable them to continue a successful research career. The PDRAs will similarly benefit from high-profile publications that result from this work. Additionally, the transferable skills obtained in both written and oral communication along with the analytical skills obtained during this research will enable the PDRAs to pursue careers inside or outside of academia. For example, in the biotechnology or pharmaceutical industry. The PhD students involved in this work would also greatly benefit from the training obtained as well as their involvement in a successful research project of this type. Other academics in the life sciences and beyond will benefit from this research in ways highlighted in the preceding "Academic beneficiaries" section.
3. What will be done to ensure that beneficiaries have the opportunity to engage with this research? Firstly, we will present our work at national conferences (British Neuroscience Association and Physiological Society) and international conferences (Society for Neuroscience, Federation European Neuroscience Associations) before publishing our work in peer-reviewed open-access journals. We will issue press releases to explain our peer-reviewed publications to the wider public - Imperial College and Kings College London are strong in this activity and their websites contain daily advertising for the new research emerging from the many researchers. Imperial College holds an annual Festival weekend (in May) at South Kensington (next to the Natural History and Science Museums) where members of the public come into the College for interactive and fun scientific displays in the campus grounds. By Googling "Imperial College" and "Festival" you can see a movie with highlights of this year's festival events. The Natural History Museum also runs late ("party") nights for the public, and the museum staff often ask Imperial to provide installations. King's has recently inaugurated the Museum of Life Sciences, at KCL (Guy's Campus) which aims, among other things, to deliver impact towards education in the local society. The Museum uses its range of expertise and specimens to promote the Life Sciences to communities outside King's College and especially to local schools with which it has special links. The Museum also runs special lectures and workshops for teachers as part of their continuing professional development. We would plan to be involved in these organisations' activities to highlight the work we are doing on this research.