Instructor, Anesthesiology, Perioperative and Pain Medicine
Residency: Stanford University Anesthesiology Residency (2021) CA
Internship: Stanford University Internal Medicine Residency (2018) CA
Medical Education: Columbia University College of Physicians and Surgeons (2017) NY
Illuminating complexity in serotonin neurons of the dorsal raphe nucleus.
2022; 110 (16): 2519-2521
The function of serotonin in the mammalian brain has been challenging to unravel. In this issue of Neuron, Paquelet etal. (2022) employ microendoscopy to record over 2,000 dorsal raphe serotonin neurons, yielding new insights into their activity from the single neuron to the population level.
View details for DOI 10.1016/j.neuron.2022.07.013
View details for PubMedID 35981523
Reward expectation differentially modulates attentional behavior and activity in visual area V4.
2015; 18 (11): 1656-63
Neural activity in visual area V4 is enhanced when attention is directed into neuronal receptive fields. However, the source of this enhancement is unclear, as most physiological studies have manipulated attention by changing the absolute reward associated with a particular location as well as its value relative to other locations. We trained monkeys to discriminate the orientation of two stimuli presented simultaneously in different hemifields while we independently varied the reward magnitude associated with correct discrimination at each location. Behavioral measures of attention were controlled by the relative value of each location. By contrast, neurons in V4 were consistently modulated by absolute reward value, exhibiting increased activity, increased gamma-band power and decreased trial-to-trial variability whenever receptive field locations were associated with large rewards. These data challenge the notion that the perceptual benefits of spatial attention rely on increased signal-to-noise in V4. Instead, these benefits likely derive from downstream selection mechanisms.
View details for DOI 10.1038/nn.4141
View details for PubMedID 26479590
View details for PubMedCentralID PMC4624579
Cytokinetic furrowing in toroidal, binucleate and anucleate cells in C. elegans embryos.
Journal of cell science
2008; 121 (Pt 3): 306-16
Classical experimental studies on echinoderm zygotes concluded that the juxtaposition of two astral microtubule arrays localizes the stimulus for cytokinetic furrowing. However, recent experimental and genetic studies in Caenorhabditis elegans, Drosophila and mammalian cultured cells implicate microtubules of the central spindle, and regulatory proteins associated with this structure, suggesting that the essential conditions for furrow induction may differ from one animal cell to another. We used micromanipulation and laser microsurgery to create, in three ways, the juxtaposition of astral microtubules in C. elegans embryonic cells. In toroidal cells we observe that furrows initiate both where astral microtubule arrays are juxtaposed, and where the cortex most closely approaches the central spindle. We find that binucleate cells successfully furrow not only across the spindles, but also between unconnected spindle poles. Finally, we find that anucleate cells containing only a pair of centrosomes nevertheless attempt to cleave. Therefore, in C. elegans embryonic cells, as in echinoderms, juxtaposition of two asters suffices to induce furrowing, and neither the chromatin nor the physical structure of the central spindle are indispensable for furrow initiation. However, furrows that cross a central spindle are more likely to complete than those that do not.
View details for DOI 10.1242/jcs.022897
View details for PubMedID 18198185