PiN Faculty Member - Richard Born, MD

Richard Born, MD

Professor of Neurobiology

Harvard Medical School
Department of Neurobiology
Warren Alpert Building, Room 218
200 Longwood Avenue
Boston, MA 02115
Tel: 617-432-1307
Fax: 617 432 1321
Email: richard_born@hms.harvard.edu
Visit my lab page here.



Goal: We seek to understand the circuitry of the mammalian cerebral cortex and how it endows us with the ability to see . . . and hear and think and talk.

Approach: We study visual cortex of alert monkeys trained to report specific aspects of their visual experience. This allows us to define the neural correlates of specific percepts and then study their underlying mechanisms by activating or inactivating components of the circuit.

Techniques: Our primary tools are extracellular electrophysiology—both with single electrodes and multi-electrode arrays—and psychophysics. They are complemented by techniques that allow us to dissect and probe cortical circuitry:

· circuit tracing with genetically modified viruses (rabies and VSV)
· cortical cooling (cryoloops) to reversibly inactivate circuit elements
· microstimulation to insert specific signals into cortical circuits
· pharmacogenetics to allow us to manipulate neurons based on where they project

Current Projects:

Probing cortico-cortical feedback. Several projects in the lab are aimed at deciphering this ubiquitous, but poorly understood, aspect of cortical connectivity. We have recently shown that feedback from V2 and V3 has a relatively selective effect on the non-classical surrounds of V1 receptive fields (Nassi et al. 2013; Nassi et al. 2014). These surrounds are critical for vision, because they allow local, feature-selective responses to be modulated by the context in which they occur. This modulation is surprisingly sophisticated, and appears well suited to reduce redundancy and create sprase representations in visual cortex via input-gain control (Trott & Born 2015).

1) Using multi-electrode arrays and cortical cooling, we are exploring the role of feedback in creating feature-specific surround suppression (Alex Trott, PiN Graduate Student).
2) Using multi-contact “V-probes” to record across layers in V1 while inactivating MT with a new class of MRI-compatible cryoloops, we are testing hypotheses regarding layer-specific feedback and the role of MT feedback in generating motion-selective surround suppression (Till Hartmann, Postdoctoral Fellow).
3) In animals trained to discriminate the orientation of noisy Gabor stimuli, we are testing the predictions of a hierarchical Bayesian model of perceptual inference. This involves recordings in V1 with multi-electrode arrays while inactivating V2 feedback (Camille Gomez-Laberge, Postdoctoral Fellow).
4) Using trans-synaptically transported viruses and immunocytochemistry, we are examining how feedback interacts with local cortical circuits (Vladimir Berezovskii, Imaging Specialist).



Last Update: 3/23/2015



Publications

For a complete listing of publications click here.

 


 



© 2014 by the President and Fellows of Harvard College