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Department of Biology Faculty and Research |
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Department
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Study Abroad - Biology at St Andrews University, Scotland W&L Links
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Education Undergraduate Degree: University College of Wales, Aberystwyth, Great Britain Graduate Degree: University of Kentucky, Lexington, KY Postdoc: University of Michigan, Ann Arbor, MI
Joined W&L Faculty in 1995
Courses Taught at W&L Fundamentals of Biology (Biology 111)
Reproductive Physiology (Biology 255)
Current Research Interests Neurobiology
of Puberty - This is an ongoing project in which I am attempting to
determine the metabolic signals and sensors within the brain
which transduce metabolic information and the neurotransmitter
pathways which transmit this metabolic information to the brain region
which controls reproduction (the hypothalamus).
Currently, we are determining the role of specific metabolic
signals (eg. glucose) in the timing of puberty onset using the
developing female rat as our research model. Dr. Harney
(University of Hartford, CT) and I are long-term collaborators on the
role of metabolism in onset and frequency of seizures during development
using the developing rat fed a ketogenic diet as a model.
This rat model was originally developed as a model for juvenile
epilepsy. It has been known
since the 1920s, that treating children with ketogenic diets decreases
the frequency of epileptic seizures. However, the side effects of using
such a diet have prompted scientists to investigate the mechanism of the
dietary-induced neuroprotective effects, in the hopes of producing
appropriate drug therapies without the side effects. We have performed a
series of experiments in which we tested the hypothesis that
preferential metabolism of fatty acids in the ketogenic diet causes a
decrease in the latency to seizure in developing rats. Our results
suggest that metabolism of fatty acids preferentially induces a
neuroprotective effect such that seizure onset is delayed.
Future studies will investigate the mechanisms by which fatty
acid metabolism provides neuroprotection. Dr. K-I Maeda, Dr. H. Tsukamura (University of Nagoya, Japan) and I continue our long-term collaboration on the site of brain glucose sensors which monitor available brain glucose levels. Specifically we are interested in the mechanism of action of these glucose sensors and transduction of the resultant signal to regulate reproductive function using the adult female rat as our model. This collaboration has been ongoing since April 1999, and has continued through my 6 month sabbatical in their lab (June-Dec, 2000). Our current work has focused on specific populations of glucose sensing cells within the brainstem. Publications I'Anson, H., Manning, J.M., Herbosa, M.C., Pelt, C., Wood, R.I., Bucholtz, D.C. and Foster, D.L.: Central inhibition of gonadotropin-releasing hormone secretion in the growth-restricted hypogonadotropic female sheep. Endocrinology 141:520-527,2000. Messer, N.A. and I’Anson, H.: The nature of the metabolic signal capable of triggering onset of puberty in food-restricted, prepubertal female rats. Physiol. Behav., 68:377-382, 2000. Reyes, B.A., Estacio, M.A., I'Anson, H., Tsukamura, H. and Maeda, K.I.: Glucoprivation increases estrogen receptor alpha immunoreactivity in the brain catecholaminergic neurons in ovariectomized rats. Neurosci Lett., 299(1-2):109-12, 2001. Reyes, B.A.S., Tsukamura, H., I’Anson, H., Estacio, M.A.C., and Maeda, K-I. Estrogen receptor a expression in the hypothalamus and medulla oblongata during fasting in ovariectomized rats: a time course study and the role of catecholaminergic neurons. Endocrinology (in revision) 2002. I’Anson, H., Starer, C.A. and Bonnema, K.R.: Glucoprivic regulation of estrous cycles in the rat. Hormones and Behavior, (in revision), 2002. Harney,
J.P., Madara, J., Madara J. D. and I'Anson,
H.: Effects of acute inhibition of fatty acid oxidation on latency
to seizure and concentrations of *
hydroxybutyrate in plasma of rats maintained on calorie restriction
and/or the ketogenic diet. Epilepsy
Res. (in press), 2002. Hickman, C.P., Roberts, L.S., Larson, A. and I’Anson, H.: “ Integrated Principles of Zoology” 12th edition, McGraw Hill (pubs), 2003.
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