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Marco Tizzano


Assistant Member, Monell Chemical Senses Center
Adjunct Assistant Professor, School of Dental Medicine, University of Pennsylvania


Ph.D., Congenital Metabolic Physiopathology, University of Verona, Italy

Research Summary

Chemical irritation of the airways and other mucosae is my main focus. I study solitary chemosensory cells (SCCs), a specialized chemosensitive nasal epithelial sentinel cell type innervated by the trigeminal nerve, which responds to bitter compounds, irritants, and bacterial metabolites. When activated, SCCs trigger protective reflexes and inflammatory/immune responses.

At the behavioral level I’m interested in motivated avoidance responses to inhaled irritants which activate the SCCs. There are classes of irritants that are connected to non-allergic and allergic inflammation and we are interested in determining how SCCs and the trigeminal system may interact with either of these. We are also investigating which epithelial cell type is the progenitor of SCCs and other mucosa chemosensory cells (like brush cells and tuft cells) and how irritants/allergens can affect the frequency of SCCs and the mucosa microbiome. Finally, I’m also particularly interested in long-range inflammation of the meninges as a consequence of nasal irritation and the mechanisms underlying neurovascular pathophysiology, such as headaches and migraines, which are triggered by exposure to airborne irritants, odorants, and bacterial molecules.

My lab’s current research projects include: (1) testing whether activation of the SCCs by irritants/odorants triggers long-range meningeal inflammation and studying the mechanisms underlying migraine pathophysiology, (2) better understanding the avoidance behavior responses to inhaled irritants, (3) studying the effect of nicotine and bacterial compounds on mucosal proliferation, inflammation, immune cells response, mucosal repair and microbiome alteration and the link between SCCs and cystic fibrosis, (4) studying the effect of irritants and allergens on airway inflammation and the role of SCCs in allergic and non-allergic inflammation, (5) identifying the progenitor cell type for SCCs and other chemosensory cells, and (6) understanding the interaction between the SCC/trigeminal pathway and the olfactory reception/perception of odorants.


Solitary chemosensory cells, extra-oral taste receptors, irritants, Pseudomonas aeruginosa, nicotine, trigeminal, allergic and non-allergic inflammation, proliferation, olfaction, avoidance behavior, airway diseases, migraine, Cystic fibrosis

Recent Publications

Tizzano, M.; Grigereit, L.; Shultz, N.; Clary, M.S.; Finger, T.E. (2015) Immunohistochemical analysis of human vallate taste buds. Chemical Senses, (in press).

Saunders, C.J.; Christensen, M.; Finger, T.E.; Tizzano, M. (2014) Cholingeric Neurotransmission Links Solitary Chemosensory Cells to Nasal Inflammation. Proceedings of the National Academy of Sciences USA, 111, 6075-6080.

Tizzano, M.; T. E. Finger. (2013) Chemosensors in the nose: guardians of the airways. Physiology (Bethesda), 28, 51-60.

Barham, H.P.; Anderson, C.B.; Tizzano, M.; Cooper, S.E.; Kingdom, T.T.; Finger, T.E.; Kinnamon, S.C.; Ramakrishnan, V.R. (2013) Solitary chemosensory cells and bitter taste transduction elements in human sinonasal mucosa. International Forum of Allergy & Rhinology, 3, 450-457.

Aherne, C.M.; Collins, C.B.; Masterson, J.C.; Tizzano, M.; Boyle, T.A.; Westrich, J.A.; Parnes, J.A.; Furuta, G.T.; Rivera-Nieves, J.; Eltzschig, H.K. (2012) Neuronal guidance molecule netrin-1 attenuates inflammatory cell trafficking during acute experimental colitis. Gut, 61, 695-705.

Tizzano, M.; Cristofoletti, M.; Sbarbati, A.; Finger, T.E. (2011) Expression of taste receptors in solitary chemosensory cells of rodent airways. BMC Pulmonary Medicine. doi:10.1186/1471-2466-11-3.

Vandenbeuch, A.; Tizzano, M.; Anderson, C.B.; Stone, L.M.; Goldberg, D.; Kinnamon, S.C. (2010) Evidence for a role of glutamate as an efferent transmitter in taste buds. BMC Neuroscience. doi: 10.1186/1471-2202-11-77.

Tizzano, M.; Gulbransen, B.D.; Vandenbeuch, A.; Clapp, T.R.; Herman, J.P.; Sibhatu, H.M.; Churchill, M.E.; Silver, W.L.; Kinnamon, S.C.; Finger, T.E. (2010) Nasal Chemosensory Cells Utilize Bitter Taste Signalling to Detect Irritants and Bacterial Signals. Proceedings of the National Academy of Sciences USA, 107, 3210-3215.

Sbarbati, A.; Tizzano, M.; Merigo, F.; Benati, D.; Nicolato, E.; Boschi, F.; Cecchini, M.P.; Scambi, I.; Osculati, F. (2009) Acyl homoserine lactones induce early response in the airway. Anatomical record (Hoboken), 292, 439-448.

Tizzano, M.; Dvoryanchikov, G.; Barrows, J.K.; Kim, S.; Chaudhari, N.; Finger, T.E. (2008) Expression of Galpha14 in sweet-transducing taste cells of the posterior tongue. BMC Neuroscience. doi: 10.1186/1471-2202-9-110.

Tizzano, M.; Merigo, F.; Sbarbati, A. (2006) Evidence of solitary chemosensory cells in a large mammal: the diffuse chemosensory system in Bos taurus airways. Journal of Anatomy, 209, 333-337.