Cortical information processing and circuit mechanisms of plasticity

Dr. Sonja Hofer

Wellcome Trust Research Career Development Fellow

Tel: +44 (0)20 7679 6381

Email: s.hofer@ucl.ac.uk


Dr. Sonja Hofer graduated in 2002 with a degree in Biology from the Technical University Munich. She completed her PhD and short postdoctoral studies with Mark Hübener and Tobias Bonhoeffer at the Max Planck Institute of Neurobiology in Martinsried, Germany. Following a second postdoc with Thomas Mrsic-Flogel at UCL with funding from the Humboldt Foundation and EMBO, she was awarded a Wellcome Trust Research Career Development Fellowship in 2011 to establish her independent research group.

Our brains constantly have to adapt to changes in the environment. Therefore neuronal circuits cannot be completely hardwired, but require the capacity to change, and to integrate and store new information about the world around us. This is especially important during development when circuits are first set up, but also later in life to enable learning and memory formation. Learning alters our perceptions, cognition and behaviour by modifying neuronal circuits within and between different brain regions. Understanding how this happens is crucial for understanding normal brain function, and for devising therapeutic approaches for correcting disorders of information storage and retrieval such as dementia. Yet the mechanisms of learning in the intact brain are not well understood. How new information is stored in neuronal circuits and how new experiences, which are behaviourally relevant for the animal, alter single cells, their connections and the flow of information through neuronal networks, remain fundamental questions in neuroscience.

In my lab we are studying the mechanisms by which neocortical circuits give rise to sensations, how these circuits are set up during development and how they are changed and shaped by new experiences and learning. Using the mouse visual cortex as a model system we are employing state of the art in vivo imaging of function and structure, electrophysiological and genetic techniques to visualize neurons, their activity and visual response properties and their synapses in the intact brain and follow changes over time while animals are learning or making new experiences.

Selected publications:

van Versendaal D, Rajendran R, Saiepour MH, Klooster J, Smit-Rigter L, Sommeijer JP, De Zeeuw CI, Hofer SB, Heimel JA, Levelt CN (2012) Elimination of inhibitory synapses is a major component of adult ocular dominance plasticity. Neuron, 74 (2): 374-383

Hofer SB, Ko H, Pichler B, Vogelstein J, Ros H, Zeng H, Lein E, Lesica N, Mrsic-Flogel T (2011) Differential connectivity and response dynamics of excitatory and inhibitory neurons in visual cortex. Nature Neuroscience, 14 (8): 1045-1052

Ko H, Hofer SB, Pichler B, Buchanan K, Sjostrom JP, Mrsic-Flogel TD (2011) Functional specificity of local synaptic connections in neocortical networks. Nature, 473 (7345): 87-91

Hofer SB, Mrsic-Flogel TD, Horvath D, Grothe B, Lesica NA (2010) Optimization of population decoding with distance metrics. Neural Networks, 23 (6): 728-732

Hofer SB, Bonhoeffer TB (2010) Dendritic spines: the stuff that memories are made of? Current Biology, 20 (4): 157-159

Hofer SB (2010) Structural traces of past experience in the cerebral cortex. Journal of Molecular Medicine, 88 (3): 235-239

Hofer SB, Mrsic-Flogel TD, Bonhoeffer T, Hübener M (2009) Experience leaves a lasting structural trace in cortical circuits. Nature, 457 (7227): 313-317

Holtmaat A, Bonhoeffer T, Chow DK, Chuckowree J, De Paola V, Hofer SB, Hübener M, Keck T, Knott G, Lee WC, Mostany R, Mrsic-Flogel TD, Nedivi E, Portera-Cailliau C, Svoboda K, Trachtenberg JT, Wilbrecht L (2009) Long-term, high-resolution imaging in the mouse neocortex through a chronic cranial window. Nature Protocols, 4 (8): 1128-1144

Mank M, Santos AF, Direnberger S, Mrsic-Flogel TD, Hofer SB, Stein V, Hendel T, Reiff DF, Levelt C, Borst A, Bonhoeffer T, Hübener M, Griesbeck O (2008) A genetically encoded calcium indicator for chronic in vivo two-photon imaging. Nature Methods, 5 (9): 805-811

Mrsic-Flogel TD, Hofer SB, Ohki K, Reid RC, Bonhoeffer T, Hübener M (2007) Homeostatic regulation of of eye-specific responses in visual cortex during ocular dominance plasticity. Neuron, 54 (6): 961-972

Hofer SB, Mrsic-Flogel TD, Bonhoeffer T, Hübener M (2006) Lifelong learning: ocular dominance plasticity in mouse visual cortex. Current Opinion in Neurobiology, 16 (4): 451-459

Hofer SB, Mrsic-Flogel TD, Bonhoeffer T, Hübener M (2006) Prior experience enhances plasticity in adult visual cortex. Nature Neuroscience, 9 (1): 127-132

Hofer SB, Klump GM (2003): Within- and across-channel processing in auditory masking: A physiological study in the songbird forebrain. Journal of Neuroscience, 23(13): 5732-5739