MATTHEW ENNIS, PH.D.

Simon R. Bruesch Professor and Chair

Department of Anatomy and Neurobiology

The University of Tennessee College of Medicine

Address

The University of Tennessee Health Science Center

855 Monroe Avenue, Suite 515

Memphis, TN 38163

Tel: (901) 448-1225; Fax: (901) 448-7193;

Lab: 322 Wittenborg Anatomy Building

Education

Ph.D. Institution: New York University

Postdoctoral: University of Cincinnati College of Medicine, Departments of Physiology & Biophysics and Anatomy & Cell Biology

Research Interests

My primary interests are centered on the functional organization and physiological properties of neural networks involved in nociception/analgesia processing and the chemical senses (i.e., olfaction and gustation). My research utilizes an integrative, multidisciplinary approach combining tract tracing, immunocytochemistry, immediate early gene expression and electrophysiology to delineate cellular and circuit properties of functionally defined networks. The major current projects in my laboratory are:

• Regulation of Brainstem Opioid Analgesic Circuits. A well defined brainstem-spinal cord circuit is known to play a key role in opioid-mediated analgesia. We are investigating how higher levels of the CNS (cortical and subcortical sites) involved in emotions, motivational state and cognitive processing can regulate this brainstem analgesic circuit to allow for state-dependent modulation of pain thresholds. We are also investigating how sweet and fatty components of mothers milk produces profound opiate receptor-dependent analgesic and calming effects in newborn rats and humans.
  
  


• Synaptic Integration and Information Processing in the Olfactory Bulb. We are investigating how neuronal membrane properties and extrinsic/intrinsic neurotransmitter systems modulate information processing and output from the olfactory bulb circuit using functional imaging and neurophysiology approaches in vivo and in vitro.


• Integration in the Olfactory Bulb (OB)-Piriform Cortex (PC) Circuit. Olfactory receptor neurons that express a single common odorant receptor project to one glomerulus in the OB. The glomeruli thus form a map that mirrors receptor activity. Different odors stimulate different patterns of glomerular activity. The OB and PC comprise the major components of the neural network that decipher such patterns to arrive at the recognition of an odor. The goal of this research is to understand how glomerular activity is relayed to, and processed within PC using neuroanatomical and neurophysiological approaches.

Recent Publications

• Dong HW, Hayar A, Callaway J, Yang XH, Nai Q, Ennis M. Group I mGluR activation enhances Ca(2+)-dependent nonselective cation currents and rhythmic bursting in main olfactory bulb external tufted cells. J Neurosci. 2009 Sep 23;29(38):11943-53. PMID: 19776280
• Dong HW, Heinbockel T, Hamilton KA, Hayar A, Ennis M. Metabotropic glutamate receptors and dendrodendritic synapses in the main olfactory bulb. Ann N Y Acad Sci. 2009 Jul;1170:224-38. PMID: 19686141
• Nai Q, Dong HW, Hayar A, Linster C, Ennis M. Noradrenergic regulation of GABAergic inhibition of main olfactory bulb mitral cells varies as a function of concentration and receptor subtype. J Neurophysiol. 2009 May;101(5):2472-84. Epub 2009 Mar 11. PMID: 19279145
• Maida V, Ennis M, Kuziemsky C, Trozzolo L. Symptoms associated with malignant wounds: a prospective case series. J Pain Symptom Manage. 2009 Feb;37(2):206-11. Epub 2008 Jul 10. Review. PMID: 18619764
• Maida V, Ennis M, Irani S, Corbo M, Dolzhykov M. Adjunctive nabilone in cancer pain and symptom management: a prospective observational study using propensity scoring. J Support Oncol. 2008 Mar;6(3):119-24. PMID: 18402303
• Mandairon N, Peace S, Karnow A, Kim J, Ennis M, Linster C. Noradrenergic modulation in the olfactory bulb influences spontaneous and reward-motivated discrimination, but not the formation of habituation memory. Eur J Neurosci. 2008 Mar;27(5):1210-9. PMID: 18364038

view complete list of references (pubmed link)