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Mary Heinricher

The interest of this laboratory is on brainstem mechanisms involved in pain modulation. Our focus is on opioid-sensitive circuits within the rostral ventral medulla, which is a crucial element in a pain-modulating network with links in the midbrain, medulla and spinal cord. This network contributes to the variability in pain sensitivity seen in different situations (for example under conditions of fear or extreme stress), and it is an important substrate for opioids and other analgesic drugs such as cannabinoids. We use single cell recording in combination with pharmacological tools to analyze how this system is activated, and we have identified two distinct classes of pain modulating neurons. ON cells are directly sensitive to opioids, and we recently showed that these neurons facilitate nociceptive transmission. OFF-cells exert a net inhibitory effect on nociception, and we were able to demonstrate that disinhibition of these neurons is central to the antinociceptive actions of opioids within the medulla. Currently, we are interested in identifying neurotransmitters that activate these two cell classes differentially to promote or suppress pain. We are also interested in how this modulatory system is activated under physiological conditions, and are looking at the inputs from limbic forebrain structures such as the hypothalamus to the rostral ventral medulla in an attempt to investigate this issue.

In addition to the degrees listed below, Dr. Heinricher was a postdoctoral fellow in neuroscience at the University of California, San Francisco, from 1983-86.

Dr. Heinricher holds joint faculty appointments in the Departments of Behavioral Neuroscience and Physiology and Pharmacology. Previous positions include Associate Professor, Depts. of Neurological Surgery, and Physiology and Pharmacology, OHSU, Portland, Ore. (1995-2001); Adjunct Assistant Professor of Neurophysiology, Department of Neurology, University of California, San Francisco, Calif. (1987-1995); Research Associate, Department of Neurology, University of California, San Francisco, Calif. (1986-87); Instructor, Department of Psychology, Division of Continuing Education, Northwestern University, Evanston, Ill. (1982-83).

Her non-academic interests include native plants and ethnobotany.