Optogenetic Exploration of circuits within the lateral entorhinal cortex

Lead Research Organisation: University of Edinburgh
Department Name: Biomedical Sciences

Abstract

The lateral entorhinal cortex (LEC) is part of the medial temporal lobe memory network and is thought to be very important in integrating information for effective episodic memory formation. However, compared to the medial entorhinal cortex (MEC), which is heavily involved in spatial memory, very little is known about the LEC's neuronal populations and their circuitry. Investigating the organisation of the LEC would also be important because it is one of the first areas damaged by Alzheimer's disease and other dementias. This project will investigate the functional connectivity of molecularly defined cell populations in the LEC, using optogenetics and electrophysiology.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M010996/1 01/10/2015 30/09/2023
1809625 Studentship BB/M010996/1 01/10/2016 30/09/2020 Christina Brown
 
Description My work has been focused in how memories are formed in the mouse and the circuits involved in how remembering certain objects, environments or contextual information can produce a snap-shot of a whole memory. The circuit involved are the lateral entorhinal cortex (LEC) and the medial entorhinal cortex (MEC), with the LEC being more important in encoding object information and the MEC more important in encoding spatial information. The two areas have similar outputs to the hippocampus, a area thought to be very important in consolidating memories long term. However their local circuitry and inputs from other parts of the brain could be important in how these two areas have different roles in memory formation. I have looked into both throughout my PhD but will focus on the differences in long range inputs to the entorhinal cortex.
Throughout my PhD I have studied a pathway from the emotional centre of the brain (the amygdala) that sends far more projections to the LEC and the MEC. Also many parts of the amygdala (several areas are involved in different emotional states, like fear or reward) send projections to the LEC but only those areas involved in fear consolidation send projections to the MEC. Even though fewer projections are sent from the amygdala to the MEC, they may be more precise as they input to areas that are very important in increased learning and memory.
To study this I have injected various viruses into mice that encode a fluorescent reporter or an opsin to projections from the amygdala to the entorhinal cortex. I electrically record the cells in the entorhinal cortex to see if they receive input from the amygdala by shining a blue light to activate the opsin gene inserted into amygdala neuron projections. I can then block the activation with various drugs to determine the type of connection that occurs between the two areas. I also injected a retrograde virus in mice into the LEC or MEC so that a fluorescent reporter is transported from there to the cells that originally projected to it in the amygdala.
Exploitation Route The next step in this research would be to see how these circuits are involved in memory formation in a mouse. The circuits could be be manipulated, either by silencing the projection the amygdala or increasing its activity, and then seeing how the mice interact in various memory tasks. These could assess emotional memory consolidation (pavlovian fear conditioning) or object and spatial memory consolidation. This could then be used to study how emotions are important in memory consolidation and could be used to study disorders that involve a disruption in the emotional salience of a memory and its context (post traumatic stress disorder). It could also be important in understanding disorders of memory as in dementia (Alzheimer's disease) or reasons for symptoms observed in neurodevelopmental disorders like Fragile X Syndrome.
Sectors Healthcare,Pharmaceuticals and Medical Biotechnology

 
Description PIPS at Scottish Government: Tobacco Control Team - Science Policy internship
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Gave evidence to a government review
URL https://www.gov.scot/publications/raising-scotlands-tobacco-free-generation-tobacco-control-action-p...
 
Description Unofficial collaboration with ffrench-Constants lab - University of Edinburgh 
Organisation University of Edinburgh
Department MRC Centre for Regenerative Medicine
Country United Kingdom 
Sector Academic/University 
PI Contribution I plan to assist Dr Maqsood Ahmed in injecting retrograde tracers to neonatal mouse pups for corrections to his submitted scientific paper. I will inject the tracers and perfuse the animals before handing the brains to him for histologicla analysis.
Collaborator Contribution If the experiment works well then it will be included in a published paper
Impact I will be trained in new techniques - intracranial injections in P0-3 mice and perfusing said mice. I have learned more about the project that initiated this experiment.
Start Year 2019
 
Description CellBlock Science - Teaching prisoners about neuroscience in Shotts and Low Moss prison, Glasgow 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Feb 21st and Feb 26th 2019:
Cellblock Science is an initiative set up by St Andrews and Strathclyde University that aims to promote outreach activities in prisons around Scotland. Myself and post-doctoral researcher attended two day sessions at adult male prisons - Shotts and Low Moss on the central belt. We planned a presentation and experiments on how the brain aids in spatial navigation - showing videos and images from previous research and conducting distance estimation and triangulation tasks while taking away visual cues. The first session at Shotts lasted 3 hours with the general population - they were extremely engaged and had a lot of interesting questions about spatial navigation and neuroscience in general. They loved the experiments and trivia quiz after. The second session was with the protected population but they were still heavily engaged. The 'learners' handed in evaluations with lots of comments on how interested they found the session and how they wish to learn more in the future. The project as a whole has been great for these learners and some are about to start OU degrees in biology.
Year(s) Of Engagement Activity 2019
URL https://news.st-andrews.ac.uk/archive/cell-block-science/
 
Description Leaders in Life Innovation Joint Symposium with University of Tokyo - visit 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Postgraduate students form the University of Tokyo were invited to the University of Edinburgh (Centre for Integrative Physiology) to observe experiments and learn about research in the building. Postgraduate students from Edinburgh presented research and showed them experiments. I showed them around the electrophysiology lab and conducted optogenetic experiments with them. they gained insight into what was going on in Edinburgh and got to experience Scotland. I believe this was intended to aid in potential collaborations in the future.
Year(s) Of Engagement Activity 2017
 
Description Nuffield Foundation - Research supervisor of school student for 6 weeks 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact The Nuffield Foundation offers 5th year school students the chance to work in a laboratory for 5-6 weeks over the summer holidays. This is to assist in getting underprivileged students more accessibility in getting into STEM at top universities. I wrote up a project for prospective school students to apply for - picked one and supervised/mentored him throughout the school holidays. He was taught in vitro electrophysiology, histology techniques, confocal microscopy and neuronal tracing techniques on Neurolucida. At the end of his project he had to write a 3000-5000 word report and present a scientific poster at an event with the other Nuffield students in August 2018. It was an enjoyable experience supervising someone with little experience in the lab and it helped me in techniques in teaching. The student has been given conditional/unconditional offers in all applied courses.
Year(s) Of Engagement Activity 2018
URL http://www.nuffieldfoundation.org/nuffield-research-placements
 
Description Routes Into Employment Event - Currie Cummunity High School 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact As part of the STEM ambassador initiative - I signed up to talk to school children at Currie Community High School in Edinburgh. The session ran from 9.30-12.20pm and was mainly attended by 3rd year students deciding what they should do after their National 4/5's. I was with a lot of other people form STEM backgrounds, most of them engineers. Groups of students would come round and ask us about subjects taken in school, getting into university and what our jobs are like. The school takes in a wide catchment area with students from varying socioeconomic backgrounds. This event gave the students insight into different options for careers and their plans for school. I also got the chance to speak to senior pupils who were interested in biomedical sciences - I gave advice on university selection and Nuffield research placements.
Year(s) Of Engagement Activity 2019
 
Description School visit - Drummond Community High School. STEM 'speed dating' 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact As part of the STEM ambassador initiative - I signed up to tlak to school children at Drummond Community High School in Edinburgh.the session ran from 9-11am and acted as a 'speed dating' session for 2nd and 3rd year pupils, separately. I was with a lot of other people form STEM backgrounds, most of them engineers. Groups of students would come round and ask us about subjects taken in school, getting into university and what our jobs are like. This was important for students picking their national 4 subjects or thinking about what to take for Highers. The school takes in a wide catchment area with students from varying socioeconomic backgrounds. This event gave the students insight into different options for careers and their plans for school. I also got the chance to speak to senior pupils who were interested in biomedical sciences - I gave advice on university selection and Nuffield research placements.
Year(s) Of Engagement Activity 2019
 
Description Science Insights 2017 - school visit to university labs 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Six year students from local schools in Edinburgh were invited to The University of Edinburgh to observe what working in a lab would be like -24/25th July 2017. Students were split into groups of 3/4 and were sent to researchers or postgraduate students to experience their research. I showed 4 students around our lab in the morning and afternoon session - shoeing them in vitro electrophysiology experiments and optogenetics. I also gave a brief introduction to neuroscience and answered questions involving UCAS applications and future careers. The next day I joined more postgraduate students to take part in a 'speed dating' scenario for the entire cohort of students. They would move round us all and ask questions mainly to do with careers and applying for universities. The intended purpose of these visits was to increase awareness of careers in STEM, especially in academia. Many students came from various backgrounds and may have not know all the avenues available to them for getting into research.
Year(s) Of Engagement Activity 2017
URL https://www.ed.ac.uk/medicine-vet-medicine/outreach/science-insights
 
Description Science Insights 2019 - school visit to university labs 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Six year students from local schools in Edinburgh were invited to The University of Edinburgh to observe what working in a lab would be like 23rd-24th July 2019. Students were split into groups of 3/4 and were sent to researchers or postgraduate students to experience their research. I showed 2 students around our lab in the morning and afternoon session - showing them in vitro electrophysiology experiments and optogenetics. They assisted in histology experiments (mounting slices) and took part in the Virtual Reality task that had been set up by another PhD student in the lab (Harry Clarke). I also gave a brief introduction to neuroscience and answered questions involving UCAS applications and future careers.
The next day I joined more postgraduate students to take part in a 'speed dating' scenario for the entire cohort of students. They would move round us all and ask questions mainly to do with careers and applying for universities. The intended purpose of these visits was to increase awareness of careers in STEM, especially in academia. Many students came from various backgrounds and may have not know all the avenues available to them for getting into research.
Year(s) Of Engagement Activity 2019
URL https://www.ed.ac.uk/medicine-vet-medicine/outreach/science-insights