Natasha Kumar

Senior Lecturer

Research: 

My lab investigates cellular and physiological mechanisms used by autonomic systems; cardiovascular, respiratory and glucoregulatory. Physiological reflexes (e.g. baroreflex, chemoreflex, glucose counterregulation) function to maintain homeostasis in the healthy state. They are integrated by neuronal circuits in the brain, and their long term and short term patency is continually regulated by genetic and environmental factors. Pathological regulation can form the basis for disease (respiratory disorders, hypertension, diabetes). How do homeostatic systems - which are vital for survival - adapt to changing environmental conditions? How do environmental challenges contribute to neuronal excitability, physiological processes and drug action?

We have expertise in cutting-edge tools and techniques (molecular methods, mouse genetics, imaging techniques, viral mediated gene rescue and knockdown) that are currently revolutionizing neuroscience. We use these skills to interrogate alterations in autonomic systems following physiological/environmental stress and provide avenues for therapy based on molecular understanding of disease processes.

Qualifications: BMedSc (Hons1) USYD, PhD USYD

 

PhD and Honours projects/topics available include:

TOPIC - Respiratory chemoreception: Inhibitory neuropeptides in respiratory chemoreceptors: what is their contribution to ventilatory behaviour? How is this role altered during chronic respiratory/environmental stress (e.g. sleep apnea, chronic obstructive pulmonary disease, obesity hypoventilation syndrome, apnea of prematurity).

Project 1: This project will investigate human infant brain chemoreceptor populations. The effects of acute versus chronic intermittent hypercapnic hypoxia on protein expression in these chemoreceptor populations will be determined. Finally, protein expression changes in Sudden Infant Death Syndrome (SIDS), compared to control infants will be investigated.

Project 2: Does chronic hypercapnia exposure cause neuroinflammation? Implications for sleep apnea and apnea of prematurity

Project 3: Does chronic hypercapnia exposure alter neuropeptide protein expression in brain respiratory chemoreceptor populations? Implications for sleep apnea

 

TOPIC - Glucose counterregulation: Nearly all sympathetic preganglionic neurons that are activated by hypoglycaemia, to execute adrenalin release via adrenal chromaffin cells, are enkephalinergic. In human studies, the similarities between hypoglycemia associated autonomic failure (HAAF) and exercise associated autonomic failure (EAAF) suggest that they share a common pathophysiology. How do endogenous opioid neuropeptides regulate the glucose countergulatory response to hypoglycemia? How is deterioration in the response to hypoglycemia seen in Type 1 diabetic patients also induced by exercise? 

 

Teaching:  Contributions to pharmacology teaching for both science and medical students. Particular areas of expertise are autonomic neuroscience, animal behaviour and cardiorespiratory physiology.

Society Memberships & Professional Activities: Society for Neuroscience, American Physiological Society, Australasian Neuroscience Society, Franklin Women.

 

Journal articles
add
Toor RUAS; Sun QJ; Kumar NN; Le S; Hildreth CM; Phillips JK; McMullan S, 2019, 'Neurons in the Intermediate Reticular Nucleus Coordinate Postinspiratory Activity, Swallowing, and Respiratory-Sympathetic Coupling in the Rat', The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 39, pp. 9757 - 9766, http://dx.doi.org/10.1523/JNEUROSCI.0502-19.2019
2019
Dereli AS; Yaseen Z; Carrive P; Kumar NN, 2019, 'Adaptation of Respiratory-Related Brain Regions to Long-Term Hypercapnia: Focus on Neuropeptides in the RTN', Frontiers in Neuroscience, vol. 13, http://dx.doi.org/10.3389/fnins.2019.01343
2019
Parker LM; Le S; Wearne TA; Hardwick K; Kumar NN; Robinson KJ; McMullan S; Goodchild AK, 2017, 'Neurochemistry of neurons in the ventrolateral medulla activated by hypotension: Are the same neurons activated by glucoprivation?', Journal of Comparative Neurology, vol. 525, pp. 2249 - 2264, http://dx.doi.org/10.1002/cne.24203
2017
Shi Y; Abe C; Holloway BB; Shu S; Kumar NN; Weaver JL; Sen J; Perez-Reyes E; Stornetta RL; Guyenet PG; Bayliss DA, 2016, 'Nalcn is a “leak” sodium channel that regulates excitability of brainstem chemosensory neurons and breathing', Journal of Neuroscience, vol. 36, pp. 8174 - 8187, http://dx.doi.org/10.1523/JNEUROSCI.1096-16.2016
2016
Guyenet PG; Bayliss DA; Stornetta RL; Ludwig MG; Kumar NN; Shi Y; Burke PGR; Kanbar R; Basting TM; Holloway BB; Wenker IC, 2016, 'Proton detection and breathing regulation by the retrotrapezoid nucleus', Journal of Physiology, vol. 594, pp. 1529 - 1551, http://dx.doi.org/10.1113/JP271480
2016
Le S; Turner AJ; Parker LM; Burke PG; Kumar NN; Goodchild AK; McMullan S, 2016, 'Somatostatin 2a receptors are not expressed on functionally identified respiratory neurons in the ventral respiratory column of the rat', Journal of Comparative Neurology, vol. 524, pp. 1384 - 1398, http://dx.doi.org/10.1002/cne.23912
2016
Kumar NN; Velic A; Soliz J; Shi Y; Li K; Wang S; Weaver JL; Sen J; Abbott SBG; Lazarenko RM; Ludwig MG; Perez-Reyes E; Mohebbi N; Bettoni C; Gassmann M; Suply T; Seuwen K; Guyenet PG; Wagner CA; Bayliss DA, 2015, 'Regulation of breathing by CO2 requires the proton-activated receptor GPR4 in retrotrapezoid nucleus neurons', Science, vol. 348, pp. 1255 - 1260, http://dx.doi.org/10.1126/science.aaa0922
2015
Parker LM; Kumar NN; Lonergan T; McMullan S; Goodchild AK, 2013, 'Distribution and neurochemical characterization of neurons in the rat ventrolateral medulla activated by glucoprivation', Brain Structure and Function, vol. 220, pp. 117 - 134, http://dx.doi.org/10.1007/s00429-013-0642-3
2013
Parker LM; Kumar NN; Lonergan T; Goodchild AK, 2013, 'Neurochemical codes of sympathetic preganglionic neurons activated by glucoprivation', Journal of Comparative Neurology, vol. 521, pp. 2703 - 2718, http://dx.doi.org/10.1002/cne.23310
2013
Pardey MC; Kumar NN; Goodchild AK; Cornish JL, 2013, 'Catecholamine receptors differentially mediate impulsive choice in the medial prefrontal and orbitofrontal cortex', Journal of Psychopharmacology, vol. 27, pp. 203 - 212, http://dx.doi.org/10.1177/0269881112465497
2013
Bowman BR; Kumar NN; Hassan SF; McMullan S; Goodchild AK, 2013, 'Brain sources of inhibitory input to the rat rostral ventrolateral medulla', Journal of Comparative Neurology, vol. 521, pp. 213 - 232, http://dx.doi.org/10.1002/cne.23175
2013
Turner A; Kumar N; Farnham M; Lung M; Pilowsky P; Mcmullan S, 2013, 'Rostroventrolateral medulla neurons with commissural projections provide input to sympathetic premotor neurons: Anatomical And Functional Evidence', European Journal of Neuroscience, vol. 38, pp. 2504 - 2515, http://dx.doi.org/10.1111/ejn.12232
2013
Zhou C; Douglas JE; Kumar NN; Shu S; Bayliss DA; Chen X, 2013, 'Forebrain HCN1 channels contribute to hypnotic actions of ketamine', Anesthesiology, vol. 118, pp. 785 - 795, http://dx.doi.org/10.1097/ALN.0b013e318287b7c8
2013
Wang S; Benamer N; Zanella S; Kumar NN; Shi Y; Bévengut M; Penton D; Guyenet PG; Lesage F; Gestreau C; Barhanin J; Bayliss DA, 2013, 'TASK-2 channels contribute to pH sensitivity of retrotrapezoid nucleus chemoreceptor neurons', Journal of Neuroscience, vol. 33, pp. 16033 - 16044, http://dx.doi.org/10.1523/JNEUROSCI.2451-13.2013
2013
Parker LM; Tallapragada VJ; Kumar NN; Goodchild AK, 2012, 'Distribution and localisation of Gα proteins in the rostral ventrolateral medulla of normotensive and hypertensive rats: Focus on catecholaminergic neurons', Neuroscience, vol. 218, pp. 20 - 34, http://dx.doi.org/10.1016/j.neuroscience.2012.05.037
2012
Pardey MC; Kumar NN; Goodchild AK; Clemens KJ; Homewood J; Cornish JL, 2012, 'Long-term effects of chronic oral ritalin administration on cognitive and neural development in adolescent Wistar Kyoto rats', Brain Sciences, vol. 2, pp. 375 - 404, http://dx.doi.org/10.3390/brainsci2030375
2012
Kumar NN; Allen K; Parker L; Damanhuri H; Goodchild AK, 2010, 'Neuropeptide coding of sympathetic preganglionic neurons; focus on adrenally projecting populations', Neuroscience, vol. 170, pp. 789 - 799, http://dx.doi.org/10.1016/j.neuroscience.2010.07.047
2010
Kumar NN; Ferguson J; Padley JR; Pilowsky PM; Goodchild AK, 2009, 'Differential muscarinic receptor gene expression levels in the ventral medulla of spontaneously hypertensive and Wistar - Kyoto rats: Role in sympathetic baroreflex function', Journal of Hypertension, vol. 27, pp. 1001 - 1008, http://dx.doi.org/10.1097/HJH.0b013e3283282e5c
2009
Kumar NN; Goodchild AK, 2009, 'Identification and distribution of inositol trisphosphate receptor subtypes in catecholaminergic cell groups in rat brainstem and midbrain', FASEB JOURNAL, vol. 23, http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000208621502032&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1
2009
Padley JR; Kumar NN; Li Q; Nguyen TBV; Pilowsky PM; Goodchild AK, 2007, 'Central command regulation of circulatory function mediated by descending pontine cholinergic inputs to sympathoexcitatory rostral ventrolateral medulla neurons', Circulation Research, vol. 100, pp. 284 - 291, http://dx.doi.org/10.1161/01.RES.0000257370.63694.73
2007
Kumar NN; Goodchild AK; Li Q; Pilowsky PM, 2006, 'An aldosterone-related system in the ventrolateral medulla oblongata of spontaneously hypertensive and Wistar-Kyoto rats', Clinical and Experimental Pharmacology and Physiology, vol. 33, pp. 71 - 75, http://dx.doi.org/10.1111/j.1440-1681.2006.04326.x
2006
Speirs HJL; Katyk K; Kumar NN; Benjafield AV; Wang WYS; Morris BJ, 2004, 'Association of G-protein-coupled receptor kinase 4 haplotypes, but not HSD3B1 or PTP1B polymorphisms, with essential hypertension', Journal of Hypertension, vol. 22, pp. 931 - 936, http://dx.doi.org/10.1097/00004872-200405000-00014
2004
Kumar N; Benjafield AV; Lin RCY; Wang WYS; Stowasser M; Morris BJ, 2003, 'Haplotype analysis of aldosterone synthase gene (CYP11B2) polymorphisms shows association with essential hypertension', Journal of Hypertension, vol. 21, pp. 1331 - 1337, http://dx.doi.org/10.1097/00004872-200307000-00022
2003
Book Chapters
add
Kumar NN; Bowman BR; Goodchild AK, 2012, 'Combined in situ hybridization and immunohistochemistry in rat brain tissue using digoxigenin-labeled riboprobe', in Badoer E (ed.), Visualization Techniques. Neuromethods, Humana Press, pp. 31 - 52, http://dx.doi.org/10.1007/978-1-61779-897-9_2
2012
Conference Papers
add
Kumar NN; Allen K; Damanhuri H; Parker L; Goodchild AK, 2009, 'NEUROPEPTIDE CODING OF ADRENALLY PROJECTING SYMPATHETIC PREGANGLIONIC NEURONS', in HYPERTENSION, LIPPINCOTT WILLIAMS & WILKINS, Sydney, AUSTRALIA, pp. 1499 - 1499, presented at 31st Annual Scientific Meeting of the High-Blood-Pressure-Research-Council-of-Australia, Sydney, AUSTRALIA, 01 December 2009 - 03 December 2009, http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000277848100065&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1
2009
Kumar NN; Goodchild AK, 2008, 'IDENTIFICATION AND DISTRIBUTION OF INOSITOL TRISPHOSPHATE RECEPTOR ISOFORMS IN CATECHOLAMINERGIC CELL GROUPS IN RAT BRAINSTEM', in HYPERTENSION, LIPPINCOTT WILLIAMS & WILKINS, Melbourne, AUSTRALIA, pp. 1110 - 1110, presented at 30th Annual Scientific Meeting of the High-Blood-Pressure-Research-Council-of-Australia, Melbourne, AUSTRALIA, 03 December 2008 - 05 December 2008, http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000266239300094&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1
2008
Pilowsky PM; Abbott SB; Burke PGR; Farnham MMJ; Hildreth CM; Kumar NN; Li Q; Lonergan T; McMullan S; Spirovski D; Goodchild AK, 2008, 'Metabotropic neurotransmission and integration of sympathetic nerve activity by the rostral ventrolateral medulla in the rat', in Clinical and Experimental Pharmacology and Physiology, pp. 508 - 511, http://dx.doi.org/10.1111/j.1440-1681.2008.04906.x
2008
Bowman BR; Kumar NN; Goodchild AK, 2008, 'ADENYLATE CYCLASE ISOFORM mRNA EXPRESSION WITHIN THE ROSTRAL VENTROLATERAL MEDULLA IN SPONTANEOUSLY HYPERTENSIVE RATS', in HYPERTENSION, LIPPINCOTT WILLIAMS & WILKINS, Melbourne, AUSTRALIA, pp. 1102 - 1103, presented at 30th Annual Scientific Meeting of the High-Blood-Pressure-Research-Council-of-Australia, Melbourne, AUSTRALIA, 03 December 2008 - 05 December 2008, http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000266239300055&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1
2008
Kumar NN; Li Q; Goodchild AK; Pilowsky PM, 2004, 'Differential gene expression of renin-angiotensin-aldosterone-nitric oxide components in the rat brainstem: SHR vs WKY', in CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, BLACKWELL PUBLISHING ASIA, Glasgow, SCOTLAND, pp. A15 - A15, presented at 30th International Geographical Congress 2004, Glasgow, SCOTLAND, http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000222184200059&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1
2004
Kumar NN; Benjafield AV; Morris BJ, 2002, 'T-344C variant of aldosterone synthase gene is associated with hypertension', in CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, BLACKWELL PUBLISHING ASIA, MELBOURNE, AUSTRALIA, pp. A43 - A43, presented at 24th Annual Scientific Meeting of High-Blood-Pressure-Research-Council-of-Australia-Inc, MELBOURNE, AUSTRALIA, 25 November 2002 - 29 November 2002, http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000184207100048&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1
2002
  • 2018-2020 NN Kumar, J Power, S McMullan, SBG Abbott. Australian Research Council Discovery Project grant. Adaptation of respiratory chemoreception: role of inhibitory neuropeptides. $400,000
  • 2018-2019 NN Kumar  Rebecca Cooper Foundation project grant $100,000
  • 2020-2021 NN Kumar NHMRC (65%) and UNSW Medicine/MWAC RIS (35%) infrastructure project grant. Zeiss microscope, ApoTome and MicroBrightfield software- fully integrated system $377,566

My group investigates the mechanisms by which our respiratory system adapts to changes in blood pH. There are specific cells in the brain that drive breathing when stimulated. These neurons are called chemoreceptors because they are sensitive to different chemical signals, such as the level of acid or base in the blood. In an effort to maintain a normal blood pH, these cells monitor the acidity of the blood, which becomes increasingly acidic in the presence of carbon dioxide (CO2), a by-product of metabolism that must be expelled. If higher than normal levels of acid are detected in the blood, these cells become excited and increase breathing to expel the excess carbon dioxide.

Broader significance of chemoreception:

  • Acid sensing neurons in the brain drive ventilation to increase breathing (Kumar NN et al 2015, Science). There is potential for drugs that activate the acid sensing neurons, to help those afflicted by respiratory diseases, such as sleep apnea.
  • Rising atmospheric CO2 causing ocean acidification has a broad impact on marine ecosystems. pH sensing mechanisms are used by fish to locate food (Caprio J et al Science 2014), oysters to build shells (Service RF 2012 Science) and coral to control calcification rates (Holcomb M et al 2014). Identification and characterization of the molecules and cellular mechanisms conferring pH sensing in marine organisms may help better predict their responses to ocean acidification, which is up 30% since preindustrial times.
  • When CO2 levels rise in the hive, worker bees show up at the hive entrance and fan in place until CO2 levels in the hive decline
  • Mosquitoes are attracted to CO2 exhaled by mammals

Undergraduate teaching


Dr Natasha Kumar completed the Foundations of University Learning and Teaching (FULT) Program in 2016.

Dr Natasha Kumar is Honours convenor for the School of Medical Sciences (Neuroscience specialisation).

Other contributions include pharmacology and neurosciences teaching for both science and medical students at UNSW. Particular areas of expertise are autonomic neuroscience, animal behaviour and cardiorespiratory physiology. I have contributed teaching to the following courses: PHAR3101 (co-convenor), PHAR3102, PHAR3251, PHAR3202 (co-convenor), NEUR2201, NEUR3211, SOMS4001, NEUR4401, SOMS3001, PHAR3306 (convenor), Neuroscience Honours (convenor).