Nandakumar Narayanan

Dr. Nandakumar Narayanan

orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2006 in Neuron
Verified
Journal Article
Closed access
NNNandakumar Narayanan
Nandakumar Narayanan
MLMark Laubach
Mark Laubach

20 October 2013 in Nature Neuroscience
Verified
Journal Article
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NNNandakumar Narayanan
Nandakumar Narayanan
JCJames F Cavanagh
James F Cavanagh
MFMichael J Frank
Michael J Frank
MLMark Laubach
Mark Laubach
Adaptive control to improve performance after making mistakes in a given task is known to involve prediction error signaling in the anterior cingulate cortex (ACC). The current study examines adaptive control in humans and rats by using comparable time-estimation tasks for each organism, and the authors show that low-frequency oscillations within the ACC in humans and the medial frontal cortex (MFC) in rats are correlated with adaptive behavioral control. They also show that these frontal oscillations are phase locked to the oscillation in the motor regions in the brain and that inactivation of the MFC in rats can disrupt both behavioral control and oscillatory coupling. In this report we describe how common brain networks within the medial frontal cortex (MFC) facilitate adaptive behavioral control in rodents and humans. We demonstrate that after errors, low-frequency oscillations below 12 Hz are modulated over the midfrontal cortex in humans and within the prelimbic and anterior cingulate regions of the MFC in rats. These oscillations were phase locked between the MFC and motor areas in both rats and humans. In rats, single neurons that encoded prior behavioral outcomes were phase coherent with low-frequency field oscillations, particularly after errors. Inactivating the medial frontal regions in rats led to impaired behavioral adjustments after errors, eliminated the differential expression of low-frequency oscillations after errors and increased low-frequency spike-field coupling within the motor cortex. Our results describe a new mechanism for behavioral adaptation through low-frequency oscillations and elucidate how medial frontal networks synchronize brain activity to guide performance.

16 September 2019 in Journal of Clinical Investigation
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Journal Article
Closed access
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RCRong Cai
Rong Cai
YZYu Zhang
Yu Zhang
JSJacob Simmering
Jacob Simmering
JSJordan Schultz
Jordan Schultz
YLYuhong Li
Yuhong Li
LLLei Liu
Lei Liu
Parkinson’s disease (PD) is a common neurodegenerative disease that lacks therapies to prevent progressive neurodegeneration. Impaired energy metabolism and reduced ATP levels are common features of PD. Previous studies revealed that terazosin (TZ) enhances the activity of phosphoglycerate kinase 1 (PGK1), thereby stimulating glycolysis and increasing cellular ATP levels. Therefore, we asked whether enhancement of PGK1 activity would change the course of PD. In toxin-induced and genetic PD models in mice, rats, flies, and induced pluripotent stem cells, TZ increased brain ATP levels and slowed or prevented neuron loss. The drug increased dopamine levels and partially restored motor function. Because TZ is prescribed clinically, we also interrogated 2 distinct human databases. We found slower disease progression, decreased PD-related complications, and a reduced frequency of PD diagnoses in individuals taking TZ and related drugs. These findings suggest that enhancing PGK1 activity and increasing glycolysis may slow neurodegeneration in PD.

1 August 2015 in Basal Ganglia
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Journal Article
Closed access
SAStephanie L. Alberico
Stephanie L. Alberico
MCMartin D. Cassell
Martin D. Cassell
NNNandakumar Narayanan
Nandakumar Narayanan

1 June 2008 in Journal of Neuroscience Methods
Verified
Journal Article
Closed access
TATimothy Allen
Timothy Allen
NNNandakumar Narayanan
Nandakumar Narayanan
DKDianna B. Kholodar-Smith
Dianna B. Kholodar-Smith
YZYanjun Zhao
Yanjun Zhao
MLMark Laubach
Mark Laubach
TBThomas H. Brown
Thomas H. Brown

19 January 2014 in Nature Neuroscience
Verified
Journal Article
Open access
PDF file
BLBenjamin B Land
Benjamin B Land
NNNandakumar Narayanan
Nandakumar Narayanan
RLRong-Jian Liu
Rong-Jian Liu
CGCarol A Gianessi
Carol A Gianessi
CBCatherine E Brayton
Catherine E Brayton
RDRalph J DiLeone
Ralph J DiLeone
The authors show that dopamine receptor 1 (D1)-expressing neurons in the medial prefrontal cortex (mPFC) of mice show increased activity in response to food intake. Using optogenetic stimulation and inhibition, they show that mPFC D1 neuron projections to the medial basolateral amygdala can increase or decrease food intake, respectively. Although the prefrontal cortex influences motivated behavior, its role in food intake remains unclear. Here, we demonstrate a role for D1-type dopamine receptor–expressing neurons in the medial prefrontal cortex (mPFC) in the regulation of feeding. Food intake increases activity in D1 neurons of the mPFC in mice, and optogenetic photostimulation of D1 neurons increases feeding. Conversely, inhibition of D1 neurons decreases intake. Stimulation-based mapping of prefrontal D1 neuron projections implicates the medial basolateral amygdala (mBLA) as a downstream target of these afferents. mBLA neurons activated by prefrontal D1 stimulation are CaMKII positive and closely juxtaposed to prefrontal D1 axon terminals. Finally, photostimulating these axons in the mBLA is sufficient to increase feeding, recapitulating the effects of mPFC D1 stimulation. These data describe a new circuit for top-down control of food intake.