Sensations and thoughts result from the coordinated activity of neuronal populations in space and time. The goal of my research is to understand the circuits controlling the spatial and temporal structure of cortical activity. Towards this goal we use in vivo and in vitro electrophysiological, imaging and anatomical approaches. Our model systems are the rodent’s somatosensory cortex and hippocampus. My lab focuses on the role played by elementary cortical circuits resulting from the interaction between excitatory and inhibitory neurons. The function of these circuits, originally recognized by Eccles as building blocks of cortical architecture, has remained elusive. We have shown that feed-forward inhibitory circuits are crucial to enforce temporal fidelity of excitatory transmission. By expanding these investigations to the somatosensory cortex, a system where temporal precision plays a fundamental role in sensory processing, we have demonstrated that faithful transmission of temporal information about a sensory stimulus crucially depends on feed-forward inhibition.
More recently, our work has shown that timing and the rate of action potentials, the two most basic forms of neuronal coding, are selectively extracted by distinct feedback inhibitory circuits. This function is performed with striking similarity by circuits in brain areas as different as the hippocampus and the somatosensory cortex, indicating a general role of these elementary circuits in cortical information processing. We are currently investigating the role played by distinct types of inhibitory circuits in modulating the dynamic range of neuronal populations.
Our work on the mechanisms by which elementary circuits operate is revealing the function and logic by which basic building blocks of cortical architecture orchestrate cortical activity.
Pouille F, Scanziani M. (2004). Routing of spike series by dynamic circuits in the hippocampus. Natur. 429(6993):717-723.
Gabernet L, Jadhav SP, Feldman DE, Carandini M, Scanziani M. (2005). Somatosensory integration controlled by dynamic thalamocortical feed-forward inhibition. Neuron 48(2):315-327.
Glickfeld LL, Scanziani M. (2006). Distinct timing in the activity of cannabinoid-sensitive and cannabinoid-insensitive basket cells. Nat. Neurosci. 9(6):807-815.
Kapfer C, Glickfeld LL, Atallah BV, Scanziani M. (2007). Supralinear increase of recurrent inhibition during sparse activity in the somatosensory cortex. Nat. Neurosci. 10(6):743-753.
Glickfeld LL, Roberts JD, Somogyi P, Scanziani M (2008) Interneurons hyperpolarize pyramidal cells along their entire somatodendritic axis. Nat Neurosci. Published online: 23 November 2008; (doi:10.1038/nn.2230).