Theoretical Neuroscience Podcast

Computational neuroscientists use many software tools, and NEURON has become the leading tool for biophysical modeling of neurons and neural network.

Today's guest has been the leading developer of NEURON since the infancy almost 50 years ago.

We talk about how the tool got started and the development up until today's modern version of the software, including CoreNEURON optimized for parallel execution of large-scale network models on multicore supercomputers.

The idea that memories are stored in molecules was popular in the middle of the 20th century. However, since the discovery of long-term potentiation (LTP) in the 1970s, the dominant view has been that our memories are stored in synapses, that is, in the connections between neurons.

Today, there are signs that the interest in molecular memory is returning, and the guest has presented a theory suggesting that molecular and synaptic memory might serve complementary needs for animals.

Is quantum physics important in determining how living systems, including brains, work?

Today's guest is a professor of molecular genetics at the University of Surrey in England and explores this question in the book "Life at the edge: The coming of age of quantum biology".

In this "vintage" episode, recorded in late 2019, we talk about how quantum physics is or may be key in photosynthesis, smelling, navigation, evolution and even thinking. And we also touch on development of new antibiotics, another expertise of McFadden.

Most computational neuroscientists investigate electric dynamics in neurons or neural networks, but there is also computations going on inside neurons.

Here the key dynamical variables are concentrations of numerous different molecules, and the signaling is typically done in cascades of chemical reactions, called signaling pathways.

Today's guest is an expert in this kind of modelling and is particularly interested in the signaling role of calcium.

Today's AI is largely based on supervised learning of neural networks using the backpropagation-of-error synaptic learning rule. This learning rule relies on differentiation of continuous activation functions and is thus not directly applicable to spiking neurons.

Today's guest has developed the algorithm SuperSpike to address the problem. He has also recently developed a biologically more plausible learning rule based on self-supervised learning. We talk about both.

Over the last ten years or so, the MindScope project at the Allen Institute in Seattle has pursued an industrylab-like approach to study the mouse visual cortex in unprecedented detail using electrophysiology, optophysiology, optical imaging and electron microscopy.

Together with collaborators at Allen, today's guest has worked to integrate of these data into large-scale neural network, and in the podcast he talks about their ambitious endeavor.

Today's guest is a pioneer both in the fields of computational neuroscience and artificial intelligence (AI) and has had a front seat during their development.

His many contributions include, for example, the invention of the Boltzmann machine with Ackley and Hinton in the mid 1980s.

In this "vintage" episode recorded in late 2019 he describes the joint births of these adjacent scientific fields and outlines how they came about.

Today's guest has argued that the present dominant way of doing systems neuroscience in mammals (large-scale electric or optical recordings of neural activity combined with data analysis) will be inadequate for understanding how their brain works.

Instead, he proposes to focus on the simple roundworm C.elegans with only 302 neurons and try to reverse engineer it by means of optical stimulation and recordings, and modern machine-learning techniques.

Over the last decade topological analysis has been established as a new tool for analysis of spiking data.

Today's guest has been a pioneer in adapting this mathematical technique for use in our field and explains concepts and example applications.

We also also talk about so-called threshold-linear network model, a generalization of Hopfield networks exhibiting a much richer dynamics, where Carina has done some exciting mathematical explorations

Not all interesting network activity occurs in cortex. Networks in the spinal cord, the long thin tubular structure extending downwards from the neck, is responsible for setting up rhythmic motor activity needed for moving around.

How do these so-called central pattern generators work?

Today's guest has, together with colleagues in Copenhagen, developed a neuron-based network theory for how these rhythmic oscillations may arise even without pace-maker neurons driving the collective.