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

• Maida V, Ennis M, Kuziemsky C, Trozzolo L. Symptoms Associated with Malignant Wounds: A Prospective Case Series. J Pain Symptom Manage. 2008 Jul 9; [Epub ahead of print] 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
• Zhang YH, Ennis M. Inactivation of the periaqueductal gray attenuates antinociception elicited by stimulation of the rat medial preoptic area. Neurosci Lett. 2007 Dec 18;429(2-3):105-10. Epub 2007 Oct 11. PMID: 17980965
• Hayar A, Ennis M. Endogenous GABA and glutamate finely tune the bursting of olfactory bulb external tufted cells. J Neurophysiol. 2007 Aug;98(2):1052-6. Epub 2007 Jun 13. PMID: 17567771
• Dong HW, Hayar A, Ennis M. Activation of group I metabotropic glutamate receptors on main olfactory bulb granule cells and periglomerular cells enhances synaptic inhibition of mitral cells. J Neurosci. 2007 May 23;27(21):5654-63. PMID: 17522310

view complete list of references (pubmed link)