Research

Our laboratory is investigating the cellular mechanisms of cortical function.

Cortext as a Dynamic Functional Connectivity Machine:

Our working hypothesis is that what makes us human is the ability of our cortex to weave together the past (memories), present (context) and future (goals) into a logical flow through dynamic functional connectivity. We are examining this question through whole cell recordings, either in primary auditory, visual, or somatosensory cortical areas, in vivo in awake mice performing perceptual discrimination tasks while walking on a wheel. We are also performing targeted patch clamp recordings in vivo in waking animals using two photon microscopes, with auditory or visual stimulation, to dissect the contribution of different subtypes of neurons. Finally, extracellular recordings from identified cells using state of the art imaging-recording "optrodes" are being performed to access deeper portions of the neocortex.

Gain Modulation:

One of the most important aspects of cortical function is the rapid control of neuronal gain (responsiveness), which yields dynamic functional connectivity in the cortex. The precise mechanisms by which neuronal gain is controlled through synaptic barrages in awake, behaving mice is being actively investigated through the methods quoted above, as well as the use of optogenetic tools.

Cortical Coding Efficiency:

Stimulation of the cortex with natural stimuli, particularly in the waking, attentive state, gives rise to highly efficient and reliable neuronal responses. We are examining the mechanisms underlying this efficiency and reliability.

Subcellular Processing in Forebrain neurons:

We are examining the precise mechanisms by which information is processed in dendritic and axonal regions of neurons using state of the art voltage sensitive dye and confocal imaging techniques. We are particularly interested in our finding that local circuits may use both a "digital" and "analog" coding scheme.