16th May: Liz Coulthard
Learning from patients: effects of dopamine on memory consolidation
In this talk, I will present recent data on the role of dopamine in memory consolidation in patients with Parkinson’s disease and discuss how our conclusions from patient studies can be used to make inference about cognition in people without brain disorders. If the attendees feel it is helpful, we can also explore the range of well-characterised local clinical populations suitable for research aimed at understanding neurobiology of cognition.
23rd May: Ulrik Beierholm, University of Birmingham
How hard to work: testing a model of dopamine and reward related vigour
The question of how humans and animals make behavioural choices has been the subject of an over-whelming number of studies. However, how vigorously to execute a choice has gathered less attention, with very few developed theoretical ideas. A study by Niv et al. (2006) suggested, based on the theory of average-return reinforcement learning, that vigour should be optimally controlled by the opportunity cost of time as measured by the average rate of reward. The study further suggested that the average rate of reward could be physiologically encoded by tonic dopamine in the brain. I will explain the underlying theory and present the results of testing these ideas.
6th June: Ian Forsythe, University of Leicester
Getting excited by inhibition in theory, or is it just impossible physiology?
We will start by considering the physiological response to sound in the medial nucleus of the trapezoid body (MNTB): this receives an excitatory input from the contralateral ear (via the cochlear nucleus and the calyx of Held). The MNTB in turn provides an inhibitory output to several other nuclei of the ipsilateral superior olivary complex. Recording from one of these nuclei shows suppression of spontaneous activity during a sound and a strong burst of AP firing at the end of a sound, or during a brief gap in a sound. How you would you design and implement a molecular circuit for such a response? The answer is an exquisite example of counterintuitive minimal ‘design’, and we’ll consider what it’s good for.
20th June: Jo Sadowski
Sharp wave-ripples shape plasticity in the hippocampus
Synaptic plasticity in the hippocampus is known to be important for learning and memory. However, little is known about the potential for naturally occurring spike patterns to induce plasticity. Using a combination of in vivo and in vitro electrophysiology, I investigate the requirements for plasticity induction in the hippocampus with place cell spike patterns recorded in awake animals. My work has identified a potentially crucial role for hippocampal sharp wave-ripple oscillations in tuning the magnitude of LTP induced by behaviourally relevant spike patterns.
27th June: Jeff Bowers
Why do neurons in the cortex respond so selectively to words, objects, and faces.
A classic finding in neuroscience is that single neurons in cortex often respond to information (e.g., an image of a face) in a highly selective manner. An obvious question is why do neurons respond in this way? I’ll describe a series of neural network simulations that show that models learn to code information in a selective manner when they are trained to store many things at the same time in short-term memory.