Alan S. Bloom, PhD
University of Louisville (1974)
Phone: 414 955-8609
Functional magnetic resonance imaging (fMRI) is a specialized application of MRI technology that allows the study of functional activity in the brain. Localized intrinsic signal changes that correlate with increases in neuronal activity are non-invasively detected allowing the acquisition of high-resolution images that are dependent on brain activity rather than anatomy. We are using fMRI to examine the effects of adjuvant cancer chemotherapy on cognition and brain function “also known as chemobrain” in breast cancer patients and in a rodent model of breast cancer. We are also using this technology to better understand the actions of abuse substances in human and animal brain. The Laboratory has multiple ongoing projects.
Effects of Cancer Chemotherapy on Cognition and Brain Function in Breast Cancer Patients. Numerous anecdotal and research reports of cognitive deficits both during and after cancer chemotherapy are found in the literature. This phenomenon has been referred to as “chemobrain”. Breast cancer patients often receive adjuvant treatment with chemotherapy and many go on to become long-term cancer survivors. Thus it is important for us to better understand the possible immediate and chronic cognitive effects of systemic chemotherapy. We are using fMRI techniques to determine the nature of the changes in brain function that underlie the cognitive deficits that can result from chemotherapy and how long they last. This research is being carried out in women being treated for breast cancer. These women are examined while performing cognitive tasks using fMRI before, during and after their course of chemotherapy treatment. These studies will enable us to determine what changes in brain function are associated with chemotherapy, which chemotherapy regimens are most likely to cause them and how recovery occurs. We are also performing similar studies using a rodent model of breast cancer. This should also give us information about the biochemical causes of chemobrain and insights into what can be done during chemotherapy to minimize effects on cognition.
Investigating Cortical Function in Chronic Cannabis: Combined and Rodent and Human Imaging Studies. (Joint study with U. of Hawaii – Human Studies) The purpose of this study is to examine, using high-field (9.4 T) fMRI, the brain responses to forepaw sensory stimulation in rats treated with THC or other cannabinoids, rats chronically treated with THC but subsequently withdrawn from treatment, rats treated with CB1-antagonist, and drug-naïve rats Our hypothesis is the BOLD fMRI responses of the rat brain to forepaw sensory stimulation will show characteristic changes depending on the dose of THC administered acutely, the animal’s history of administration of THC or other cannabinoids, the duration of withdrawal from THC, and treatment with CB1-antagonist, SR14716A.
We feel that using fMRI to study the neurocognitive effects of cannabis use in humans, and to relate these findings to an animal model of THC administration should enable us (a) to gain a stronger understanding about the consequences for the brain of continuing active use of cannabis, and (b) to develop testable hypotheses for future work examining long-term use and abstinence.
Recent Publications Bloom AS, Terschner SL, Fuller SA and Stein EA: Effects of delta-9-tetrahydrocannabiol on regional cerebral blood flow in the rat. Pharmacology Biochemistry and Behavior 57: 625-631, 1997.
Stein EA, Pankiewicz J, Harsch HH, Cho JK, Fuller SA, Hoffmann RG, Hawkins M, Rao SM, Bandettini PA, Bloom AS: Nicotine-induced limbic cortical activation in the human brain: A functional MRI study. American Journal of Psychiatry 155:1009-1015, 1998.
Bloom AS, Hoffmann RG, Fuller SA, Pankiewicz J, Harsch HH, Stein EA: The determination of drug-induced changes in functional MRI signal using a pharmacokinetic model. Human Brain Mapping 8: 235-244,1999.
Garavan H, Pankiewicz J, Bloom AS, Cho-J-K, Sperry L, Ross T, Salmeron BJ, Risinger R, Kelley D, Stein EA: Cognitive dimensions of cue-induced cocaine craving. Am. J. Psychiatry 157: 1789-1798, 2000.
Risinger RC, Salmeron, BJ, Ross, TJ, Amen SL, Sanfillipo MJ, Hoffmann R, Bloom AS, Garavan H, Stein EA: Neural correlates of high and craving during cocaine self-administration using BOLD fMRI. Neruoimage 26: 1097-1108, 2005.
Kufahl P, Li Z, Risinger R, Rainey C, Wu G, Bloom AS, Li S: Neural responses to acute cocaine administration in the human brain detected by fMRI. Neuroimage 28: 905-914, 2005.
Liu H, Rainey C, Lauer KK Piacentine L, Bloom AS, Risinger R, Ward D, Stein EA, Li SJ, Peripheral blood pressure changes induced by dobutamine do not alter BOLD signals in the human brain. Neuroimage 30:745-752, 2006.
Murphy K, Dixon V, LaGrave K, Kaufman J, Risinger R, Bloom AS, Garavan H: The validation of event-related fMRI comparisons between drug groups and controls. Am J. Psychiatry 163: 1245-1251, 2006.
Kufahl P, Li Z, Risinger R, Rainer C, Piacentine L, Wu G, Bloom AS, Yang Z, Li SJ, Expectation modulates human brain responses to acute cocaine: A functional magnetic resonance imaging study. Biol. Psychiatry 63: 222-230, 2008.
Liu X, Yang Z, Li R, Xie J, Yin Q, Bloom AS, Li SJ: Responses of dopaminergic, serotonergic and noradrenergic networks to acute levo-tetrahydropalmatine administration in naïve rats detected at 9.4 Tesla. Magnetic Resonance Imaging 30: 261-270. 2012.