The Cortex Club connects researchers at the University of Oxford with world-leading neuroscientists through a unique educational forum dealing with cutting-edge topics and significant challenges in neuroscience. Our events range from small intense debates with up-and-coming scientists to large discussion sessions led by internationally prominent speakers, followed by the opportunity to ask them questions over drinks.

 

 

 

 

 

 

 

Seminar: Paul Chadderton

Combining mGRASP and optogenetics enables high-resolution functional mapping of descending cortical projections

Thursday 15 November – 4pm at the Large Lecture Theatre, DPAG/Le Gros Clarke Bldg

 

The Cortex Club is excited to host Dr Paul Chadderton from the University of Bristol, who will be talking to us about novel approaches to map both morphology and strength of synaptic connections. Please join us on November 15th at the Large Lecture Theatre, located in the Le Gros Clark Building of the Department of Physiology, Anatomy and Genetics.

 

Dr Paul Chadderton has kindly agreed to meet students and staff individually. If you would like to arrange a meeting please contact Lukas Krone (lukas.krone -at- dpag.ox.ac.uk).

 

To join us at the pub after the talk please register at https://goo.gl/forms/S4IqLbhLIs4ri3j93

Abstract
Detailed mapping of neuronal connectivity is essential to understand the function of
brain circuitry. At the cellular and circuit level, this corresponds to precise information
about the number, location and strength of synaptic inputs received onto individual
neurons. Several methods have been developed to map the anatomical distribution
of synapses across neurons, but these approaches do not provide information about
the strength of individual connections. It is therefore difficult to confirm the functional
influence of connections and circuit mapping remains incomplete. In this talk, I will
describe a new approach to infer the strength of descending cortical synapses using
the anatomical marker, mGRASP (mammalian GFP reconstituted across synaptic
partners), a light microscopy technique that labels synaptic contacts. By
combining optogenetics and mGRASP, we have mapped the number and strength of
defined corticocollicular connections and reveal synaptic weighting of defined
projections at the level of single neurons. Overall these data demonstrate how subtle
variations in the functional organisation of cortical synapses influence overall circuit
function.

Seminar: Prof Ileana Hanganu-Opatz

Cognitive ontogeny in health and disease: a story of right communication

Monday 29 October – 4pm at the Large Lecture Theatre, DPAG/Le Gros Clarke Bldg

 

The Cortex Club is delighted to present Prof Ileana Hanganu-Opatz from the University Medical Center Hamburg-Eppendorf, who will be talking to us about the maturation of the prefrontal-hippocampal networks. Please join us on October 29th at the Large Lecture Theatre, located in the Le Gros Clark Building of the Department of Physiology, Anatomy and Genetics.

 

There will be drinks and nibbles after the talk. Feel free to join us if you would like to meet Prof Ileana Hanganu-Opatz.

 

Abstract
Cognitive performance relies on the entrainment of neuronal networks in oscillatory patterns of electrical activity, as exemplified in the case of functional interplay between the prefrontal cortex and hippocampus. Coupling of neuronal networks in oscillatory rhythms emerges early during development. However, the contribution of coordinated activity for the maturation of neuronal networks remains largely unknown. The talk will introduce the mechanisms controlling the development of structural and functional coupling within prefrontal-hippocampal networks of rodents. Moreover, the dysfunction within hippocampal-prefrontal networks, switching from neonatal hypo- to juvenile hyper-coupling, will be characterized as a possible mechanism underlying the pathophysiology of cognitive deficits in neuropsychiatric disorders.

Seminar: Dr Robb Rutledge

A computational and neural model for happiness

Monday 22 October – 4pm at the Large Lecture Theatre, DPAG/Le Gros Clarke Bldg

 

The Cortex Club is excited host Dr Robb Rutledge from University College London, who will be presenting a computational approach to study happiness to us. Please join us on October 22th at the Large Lecture Theatre, located in the Le Gros Clark Building of the Department of Physiology, Anatomy and Genetics.

 

There will be drinks and nibbles after the talk. Feel free to join us if you would like to meet Dr Robb Rutledge.

 

 

Abstract
The happiness of individuals is an important metric for societies, but we know little about how the cumulative influence of daily life events are aggregated into subjective feelings. Using computational modeling, I show that momentary happiness in a decision-making task is explained not by task earnings, but by the combined influence of past rewards and expectations. The robustness of this account was evident in a large-scale smartphone-based replication. I use a combination of neuroimaging and pharmacology to investigate the neural basis of happiness, finding that it relates to dopamine. I then show that this computational approach can be used to investigate the link between mood and behaviour in psychiatric disorders including major depression and bipolar disorder.

Seminar: Prof Anne Churchland

Movement-related activity dominates cortex during sensory-guided decision making 

Friday 19 October – 4pm at the Large Lecture Theatre, DPAG/Le Gros Clarke Bldg

 

The Cortex Club is thrilled to host Associate Prof Anne Churchland from Cold Spring Harbor Laboratory, who will be talking to us about his research on neural circuits underlying decision-making. Please join us on October 19th at the Large Lecture Theatre, located in the Le Gros Clark Building of the Department of Physiology, Anatomy and Genetics.

 

Prof. Anne Churchland has kindly agreed to meet students and staff individually. If you would like to arrange a meeting please contact Tai-Ying Lee (tai-ying.lee-at- dpag.ox.ac.uk).

 

 

Abstract
An animal’s movements and internal state generate an “internal backdrop” of activity that is dynamically modulated. During behavior, this internal backdrop interacts with signals arising from incoming sensory stimuli and may have a substantial impact on task-related computations, like those underlying decision-making. To understand the joint effects of internal backdrop and task-imposed variables, we measured neural activity across the entire dorsal cortex of task-performing mice. We characterized internal backdrop using multiple measures of self-generated parameters including pupil diameter, whisking and body motion. Surprisingly, internal backdrop dominated neural activity across the entire cortex, dwarfing task-related variables and even sensory stimuli. Single neurons in frontal cortex were likewise dominated by internal backdrop. A linear model allowed us to account for multiple dimensions of internal backdrop and uncover hidden signatures of task-related activity. We show that complex, ongoing behavior fundamentally shapes neural activity throughout cortex and must be accounted for when studying decision-making.

Seminar: Prof Tara Keck

Synaptic dynamics in mouse visual cortex following sensory deprivation

Friday 19 October – 1pm at the Large Lecture Theatre, DPAG/Sherrington Bldg

 

The Cortex Club proudly presents Tara Keck from University College London, who will be talking to us about her research on homeostatic synaptic plasticity. Please join us on October 19th at the Large Lecture Theatre of the Sherrington Building of the Department of Physiology, Anatomy and Genetics.

 

Prof. Tara Keck has kindly agreed to a Q&A lunch after her talk to which students and stuff are warmly invited. If you would like to join the free sandwich held at the Sherrington Library please sign up at https:// goo.gl/forms/K436QAGEPzHMKx2u1

 

Abstract
Homeostatic synaptic scaling is thought to occur cell-wide, but recent evidence suggests this form of stabilizing plasticity can be implemented more locally in reduced preparations. To investigate the spatial scales of plasticity in vivo, we used repeated two-photon imaging in mouse visual cortex after sensory deprivation to measure TNF-α dependent increases in spine size as a proxy for synaptic scaling in vivo in both excitatory and inhibitory neurons. We found that after sensory deprivation, increases in spine size are restricted to a subset of dendritic branches, which we confirmed using immunohistochemistry. We found that the dendritic branches that had individual spines that increased in size following deprivation, also underwent a decrease in spine density. Within a given dendritic branch, the degree of spine size increases is proportional to recent spine loss within that branch. Using computational simulations, we show that this compartmentalized form of synaptic scaling better retained the previously established input-output relationship in the cell, while restoring activity levels. We then investigated the relationship between new spines that form after this spine loss and strengthening and find that their spatial positioning facilitates strengthening of maintained synapses.