Physiology and Pharmacology
Driven by anatomical data, prior literature, models, and thought experiments, we develop hypotheses about how neuromodulatory signaling interacts with local brain circuits. We test those models in behaving animals using electrophysiological and psychophysical measures as a readout of circuit activity, and task engagement and pharmacological manipulations to achieve causal control.
Current projects in the lab make use of:
- Linear electrode arrays to record single- and multi-unit activity, and field potentials generated by neurons across the layers of cortex.
- Pressure ejection and retrodialysis for drug delivery at different spatial and temporal scales.
- Passive viewing to explore modifications to basic visual receptive field properties by neuromodulators.
- Detection and discrimination tasks to ascertain the perceptual consequences of changes to receptive field tuning and other basic response properties of visual cortical neurons.
Neuromodulators modify processing by local circuits in ways that enable computational flexibility on fast timescales.
We study the means by which that flexibility is conferred by investigating modulator-induced changes in neural responses in the primary visual cortex, V1.
Questions we're currently working on in this domain include:
- In what ways does serotonin modify the gain of visual responses in the layers of V1 that receive ascending input from the thalamus?
- To what extent, and in what form, do gain changes induced by acetylcholine and serotonin acting at the input layer propagate through the V1 circuit?
- Under what circumstances do these gain changes modify perception?
- Are there differences in the ways that neuromodulators target the magnocellular and parvocellular visual pathways in V1?