New techniques for studying behaviours that require motor cortex

Moving with Cortex:
New techniques for studying behaviours that require motor cortex
UCL, November 28th, 2013
Adam R. Kampff
Group Leader – “Intelligent Systems Lab”
Champalimaud Neuroscience Programme
Lisbon, Portugal
The role for motor cortex in the control and learning of behaviour remains unclear, particularly in lower
mammals (e.g. rodents). I will first describe a new behavioral assay that demonstrates that motor cortex
is required to rapidly respond to unexpected changes in the environment. Animals respond and adapt to
these environments very quickly, highlighting the importance of observing changes in behaviour and
brain activity that occur on short timescales. I will next discuss the development of new electrical
recording methods based on ‘active’ silicon devices that make it possible to investigate, in detail, the
changes in neural activity underlying such fast behavioral adaptations. My talk will thus have two parts,
the first focused on our behavioral investigations of the role of motor cortex and the latter on the
technical developments that will allow us to investigate the neural control of these behaviors.
Part I: We constructed a new behavioural assay with which we can manipulate the “predictability” of the
environment. The assay is composed of series of obstacles coupled to a motorized brake that allows
independent control of that rotational stability for each obstacle. We tested rats (with and without bilateral motor cortex lesions) trained to shuttle back and forth across the obstacle course for water
rewards. During training, animals first learned to negotiate the assay with all of the obstacles stable, and
performance was comparable between lesion and sham animals. Following one week in this
environment, the center two steps were covertly released (i.e. made free to rotate upon contact). After
additional training, both lesion and sham groups learned to negotiate the unstable steps, achieving
similar performance. However, upon first encountering the new, unexpected state of the center
obstacles, animals without motor cortex failed to respond to the change. In contrast, control animals
either rapidly produced compensatory behaviors or immediately begin exploring (whisking and
manipulating) the altered obstacle. This finding highlights a novel role of motor cortex in the preparation
and control of fast responses to unexpected change.
Part II: Microfabrication techniques are now commonly used to produce thin, implantable neural probes
with multiple individual electrodes (~32). These are passive devices and each electrode site must have a
direct connection to the off-probe recording/stimulation electronics. However, more advanced
fabrication techniques (CMOS), which are standard in the semiconductor industry, permit the
integration of active electronics directly into the probe itself. Such “active neural probes” are not limited
by the number of connection wires that can be fit across the probe surface, and can thus monitor
thousands of distinct electrode sites. Furthermore, the incorporation of other active components (i.e.
LEDs, amplifiers, etc.) permits the construction of an entirely new class of “integrated” neural devices. I
will discuss our ongoing efforts to characterize the performance of these active devices, as well as their
potential for investigating the changes in neural activity that occur during our behavioural studies.
Brief Bio:
Adam Kampff studied astrophysics at Harvard University in Cambridge, MA. He spent many hours at the
observatory where he worked the overnight shift at a radio telescope and thought about the brain. Adam stayed at
Harvard for his PhD in neuroscience, during which he designed and built two-photon laser scanning microscopes
and investigated neural circuits that control visual behavior. After graduating in 2009 and receiving a postdoctoral
fellowship from Harvard's Mind, Brain and Behavior program, Adam began studying how the mammalian brain
controls and learns motor behaviors. In 2011, Adam moved to Lisbon, Portugal to start his own laboratory at the
Champalimaud Centre for the Unknown. The goal of his research is to understand how a nervous system
constructs a model of the world: How do brains learn about the statistics of their environment? How is this
information encoded in networks and used to control intelligent behavior? Answers to these fundamental
questions will require the development of novel devices for simultaneously recording from large populations of
neurons throughout the brain of a behaving animal. Therefore, in parallel with his neuroscience investigation of
mammalian cortex, Adam's lab also utilizes techniques from microfabrication and microelectronics to design and
construct new sensors for recording neural activity.