Stephanie Cunningham

I am a 4th year Biology (B.A.) major.  I am a member of Tri beta - a biological sciences honor society - and am about to start volunteering as an EMT with a local fire department. I came to the University of Texas almost 2 years ago from a small private school in North Carolina. My first semester here I was fortunate to begin working as an undergraduate in the Gore lab. I was matched with Sarah Dickerson - her project on endocrine-disrupting chemicals (EDCs) really fascinated me. Coming into college I never saw myself doing research but after taking 2 courses: an intro to research and 'Environmental Toxicology' I was very interested in getting some experience and seeing how/if I liked it. I am so glad I did.

The project that I have been working on with Sarah is one of the EDC projects. We are looking at how developmental exposure to PCBs influences the neonate, pubertal, and adult rat. There is strong evidence to suggest that treatment during a 'critical window' in fetal development has both an immediate as well as a long-term effect on the animal. A landmark of interest in the adult animals is estrogen receptor (ER) alpha expression in the a region of the hypothalamus called the anteroventral periventricular nucleus (AVPV) that is involved in the control of reproduction. Currently I am quantifying the expression of this receptor in this region [AVPV].

Bailey Kermath

Background: I graduated from the University of Wisconsin-Madison in 2006 with a B.S. in Biology; Neurobiology option. As an undergraduate, I worked in the laboratory of Dr. John G. White studying the role of the protein STU-10 in the rotation of the mitotic spindle during asymmetric cell division in the C. elegans early embryo. Following my undergraduate studies, I volunteered as a research technician in Capullpam de M̬ndez, Mexico for a Union de Comunidades Zapoteca-Chinanteca (UZACHI) in their edible mushroom production lab and for Estudios Rulares y Asesora Campesina and Global Environmental Management (GEM) to test the local water quality. Next, I worked as an analyst for Covance Laboratories before beginning the PhD program at UT-Austin in the Institute for Neuroscience in 2007. I first worked in the laboratory of Dr. Tim Schallert investigating the neuroprotective effects of methylene blue in a rat model of Parkinson's disease. I am currently in Dr. Andrea Gore's laboratory studying hypothalamic mechanisms underlying the transition to menopause. While at UT, I have volunteered and held offices in the Neuroscience Graduate Students' Association (NGSA), am currently Chair of the student-run Annual Neuroscience Symposium, and volunteer as a science fair judge for Mathews Elementary School.

Research: I am interested in how the gonadotropin-releasing hormone (GnRH) neurons of the hypothalamus, and their network of afferent inputs, are regulated during reproductive aging, leading to menopause in women or reproductive senescence in the female rat. GnRH neurons are the driving force of the hypothalamic-pituitary-gonadal (HPG) axis, which controls reproductive function. GnRH neurons show age-related deficits in activity that are likely regulated through intrinsic changes, as well as through changes in afferent inputs. My project focuses on changes in glutamatergic inputs on GnRH terminals in the median eminence during reproductive aging. Specifically, I use an aging female rat model to describe modulation of the glutamatergic NMDA receptor (NMDAR), an important stimulatory input to GnRH neurons, during the transition to reproductive senescence. For my project, I will analyze the gene expression and localization of NMDAR subunits on the GnRH terminals in the median eminence in rats of varying age and cycle status.

Publications:
Rojas JC, Simola N, Kermath BA, Kane JR, Schallert T, Gonzalez-Lima F. Striatal Neuroprotection with Methylene Blue. Neuroscience, 2009; 877-889.

Presentations:
Striatal Neuroprotection with Methylene Blue. Bailey A Kermath, Julio C Rojas, Nicola Simola, Jacqueline R Kane, Timothy Schallert, F Gonzalez-Lima. University of Texas at Austin.
Institute for Neuroscience Symposium, 2008, Austin, TX.

A study of the role of stu-10(oj14) in cleavage plane specification of the P1 cell in Caenorhabditis elegans. Bailey A Kermath, Maria I Vidal, John G White. University of Wisconsin-Madison.
C. elegans. Development and Evolution Topic Meeting, 2006, Madison, WI.

A study of the role of stu-10(oj14) in cleavage plane specification of the P1 cell in Caenorhabditis elegans. Bailey A Kermath, Maria I Vidal, John G White. University of Wisconsin-Madison.
International Worm Meeting 1043A, 2005, Los Angeles, CA

Michelle Naugle

I graduated Magna cum laude from Georgia State University with a B.S. in Neuoscience in December of 2006. While earning my degree I worked in Dr. Paul Katz's lab studying serotonergic modulation of the central pattern generator that controls the escape swim behavior of the mollusk Tritonia diomedea.

I joined Dr. Gore's lab in the spring of 2008. I am interested in how the brain compensates for the changes in hormone levels that accompany menopause. I will be investigating how the hypothalamus responds to hormone treatment at different ages. I am currently looking at changes in hormone receptor expression using immunohistochemistry, and will soon be looking at ultra-structural changes with electron microscopy.

Published Abstracts:

• Sakurai A, Calin-Jageman RJ, Naugle M, & Katz PS. (2005). Serotonergic enhancement of transmitter release mediates the synaptic potentiation phase of spike timing-dependent neuromodulation. Society for Neuroscience Abstracts, 31, 177.13.
• Sakurai A, Calin-Jageman RJ, Naugle M, & Katz PS. (2006). Serotonergic enhancement of transmitter release mediates the synaptic potentiation phase of spike timing-dependent neuromodulation. Southeast Nerve Net.

Honors:

• Georgia State University, Howard Hughes Biotechnology Fellowship, 2006

Penny Riha, Ph.D

I became interested in neurological research during my undergraduate studies at UT Austin.  After graduating with a BA in Psychology, I decided to attend graduate school at UT Austin with a major focus in Behavioral Neuroscience and supporting work in Toxicology.  I was interested in both normal brain aging and neurodegeneration.  I decided to study under Dr. Gonzalez-Lima due to his expertise in metabolic brain imaging and his unique perspective of the mitochondrial cause of Alzheimer's disease.  I began my graduate studies examining behavior and brain effects of metabolic-enhancing drugs on learning and memory in both young and aged rats.  For my dissertation, I independently created a unique rodent model of early-stage Alzheimer's disease called mild cognitive impairment.  After earning my Ph.D. in 2007, I decided to learn more about molecular aspects of disease and aging, and worked as a postdoctoral fellow under Dr. Michelle A. Lane in the Division of Nutritional Sciences at UT Austin.  I studied the chemotherapeutic mechanisms of retinoids in colorectal cancer cell lines.  Learning techniques ranging from RNA assays to transfection allowed me to appreciate the molecular mechanisms underlying disease. 

After finishing my postdoctoral position, I began working in June 2009 in the Laboratory of Dr. Andrea Gore within the Division of Pharmacology & Toxicology.  One major focus in the laboratory is studying reproductive function and the primary regulator, gonadotropin-releasing hormone (GnRH).  GnRH is released in the median eminence, and as such, is a major area of interest.  In addition to my role as Senior Laboratory Manager, I also manage projects that include characterizing the hypothalamic changes in ovariectomized rats receiving hormone replacement therapy.  Specifically, we are testing the hypothesis that there are critical windows of opportunity and durations of hormone treatment that will affect hypothalamic circuits regulating reproduction in aging female rats.  Another major project is based on the hypothesis that glutamate is critical in normal reproductive function and may mediate the transition to acyclicity at middle age.  We are testing the effects of chronic glutamatergic NMDA receptor agonists and antagonists on reproductive behavior and hypothalamic function.  In both projects, we are measuring steroid hormone levels using radioimmunoassays as well as quantitating membrane receptor changes using both light and confocal microscopy.  In addition, we are using electron microscopy to describe qualitative changes in the synaptic ultrastructure of the median eminence, including neural-glial relationships. 

Studying the neural mechanisms of reproductive development and aging was a natural transition from my graduate studies.  Working in the Gore Lab has allowed me to use my existing skills as well as expand my skill set in the laboratory.  I feel fortunate to work in a lab that values teamwork and encourages innovative ideas. 

Peer-Reviewed Publications

Riha PD, Rojas JC, Colorado RA, & Gonzalez-Lima F. (2008).  Animal model of posterior cingulate cortex hypometabolism implicated in amnestic MCI and AD.  Neurobiology of Learning and  Memory, 90, 112-124.

Wrubel KM, Riha PD, Maldonado, MA, McCollum D, & Gonzalez-Lima F. (2007).  The brain metabolic enhancer methylene blue improves discrimination learning in rats.  Pharmacology, Biochemistry & Behavior, 86(4), 712-717.

Riha PD, Bruchey AK, Echevarria DJ, & Gonzalez-Lima F. (2005). Memory facilitation by methylene blue: dose-dependent effect on behavior and brain oxygen consumption. European Journal of Pharmacology, 511, 151-158.

Callaway NL, Riha PD, Bruchey AK, Munshi Z, & Gonzalez-Lima F. (2004). Methylene blue improves brain oxidative metabolism and memory retention in rats. Pharmacology, Biochemistry and Behavior, 77, 175-181.

Callaway NL, Riha PD, Wrubel KM, McCollum D, & Gonzalez-Lima F. (2002). Methylene blue restores spatial memory retention impaired by an inhibitor of cytochrome oxidase in rats. Neuroscience Letters, 332, 83-86.

Lindsay Thompson

I graduated from the University of North Texas in 2008 with a B.S. in Biochemistry. After graduating I worked at UT Southwestern where I helped to develop transgenic rats and improved the cell culturing methods involved in maintaining rat spermatogonial stem cells.
 
I joined Dr. Gore's lab in November of 2009. I am currently a lab manager overseeing a project that is dedicated to studying the effects of polychlorinated biphenyls (PCBs) on the neuroendocrine system. The first goal of this project is to study the effects of PCBs on gene expression of steroid hormone receptors in the hypothalamus. The next goal of this project is to determine if fetal exposure to PCBs causes permanent effects in the hypothalamus through DNA methylation and histone modifications of steroid hormone receptors. Previous studies have shown that prenatal exposure to PCBs has an effect on the neuroendocrine system throughout development and therefore it is my goal to determine if those effects continue across three generations.

Deena Walker

Background:
I graduated from UT in 2002 with a B.S. in biology. As an undergraduate, I worked under Dr. Tom Mabry studying the estrogenic nature of compounds extracted from several plant species native to central Texas. Following this, I began research in the lab of Dr. Su Dharmawardhane and was given an independent project determining the role of TGF-Beta in breast cancer metastasis. In addition to my work in research laboratories, I worked with Dr. Delia Brownson, supervising the preparations for the upper and lower-division molecular biology lab courses at UT-Austin.
After graduation, I was hired as a technician in Dr. Cheryl Walker's laboratory at the MD Anderson Cancer Center, Research Division in Smithville, TX. While there, I studied the effects of diethylstilbesterol (DES) on the development of uterine leiomyomas in rats. The research I conducted in Dr. Walker's lab was instrumental in establishing an interest in endocrine disrupting chemicals (EDCs) and their effects on the developing fetus.
I worked for two years as a technician in Dr. Gore's laboratory prior to graduate school. While there, I served as the molecular biology specialist for the lab. I established a real-time PCR protocol and developed assays to substitute for our RNase Protection Assay (RPA) protocols, such as assays measuring the primary transcript for GnRH. I was involved in a number of molecular based projects, but was interested in those projects concerning EDCs and development in rats. I completed my own project which sought to elucidate the role of GnRH gene expression in pubertal development in male rats using real-time PCR.

Research:
I started graduate school in 2006. Since being in graduate school, I have expanded my interest in the molecular mechanisms underlying the onset of puberty in rats by studying gene expression changes in sex steroid hormone receptors in the developing preoptic area. Along with Lorenzo Perez, an undergraduate in our lab, I have also begun work identifying sex differences in gene expression in both the preoptic area and the medial basal hypothalamus. We are also interested to determine if the changes in gene expression that we have observed are associated with changes in serum hormone concentrations. Finally, I would like to determine if developmental exposure to EDCs can alter the gene expression profiles in both male and female rats. Together, I hope these studies will help to identify basic molecular mechanisms required for the onset of puberty in mammals.

Published Papers:

1. Walker DM, Gore AC (2007) Endocrine-disrupting chemicals and the brain. In: Gore AC (ed), Handbook of Endocrine-disrupting Chemicals, Humana Press, pp 63 - 109.


2. Dickerson SM, Walker DM, Reveron ME, Duvauchelle CL, Gore AC (2008) The recreational drug ecstasy disrupts the hypothalamic-pituitary-gonadal reproductive axis in adult male rats. Neuroendocrinology 88(2):95-102.


3. Maffucci JA, Walker DM, Ikegami A, Woller MJ, Gore AC (2008) The NMDA receptor subunit NR2b: Effects on LH release and GnRH gene expression in young and middle-aged rats, with modulation by estradiol. Neuroendocrinology 87(3):129-41.


4. Steinberg RM, Walker DM, Juenger TE, Woller MJ, Gore AC (2008) The effects of perinatal PCBs on adult female reproduction: Development, reproductive physiology, and second generational effects. Biology of Reproduction 78(6):1091-101.


5. Walker DM, Juenger TE, Gore AC (2009) Developmental profiles of neuroendocrine gene expression in the preoptic area in the male rat. Endocrinology 150: 2308-2316.

Abstracts:

1. Walker DM, Dubash A, Dharmawardhane SF, (2001) TGFB Signaling in Breast Cancer Progression, Undergraduate Research Poster Session, March 23, 2001 and UT-Austin Molecular Cell and Developmental Biology Departmental Retreat, March 31, 2001.
   


2. Gore AC, Steinberg RM, Walker DM (2005) Endocrine disrupting effects of PCBs on reproductive neuroendocrine function. Gulf Coast Society of Toxicology, Austin, TX.
   


3. Steinberg RM, Walker DM, Gore AC (2005) Altered adult gene expression following prenatal PCB exposure - a microarray study. Gulf Coast Society of Toxicology, Austin, TX.
   


4. Gore AC, Steinberg RM, Walker DM (2005) Fetal PCB exposure disrupts reproductive physiology and behavior in adulthood. NIEHS Grantee Meeting, Durham, NC.
   


5. Walker DM, LaPlant Q, Maffucci JA, Gore AC (2005) Hypothalamic GnRH gene expression profile in developing male rats, assayed by two quantitative methods. Endocrine Society, San Diego, CA.
   


6. Walker DM, LaPlant Q, Maffucci JA, Gore AC (2005) Hypothalamic GnRH gene expression profile in developing male rats, assayed by two quantitative methods. Endocrine Society Forum on Endocrine-Disrupting Chemicals, San Diego, CA.
   


7. Steinberg RM, Walker DM, Gore AC (2005) Prenatal PCB exposure results in altered development and sexual behaviors in female rats. Endocrine Society Forum on Endocrine-Disrupting Chemicals, San Diego, CA.
   


8. Dickerson SM, Walker DM, Steinberg RM, Dangleben NL, Gore AC (2005) Mechanisms for polychlorinated biphenyl actions on GnRH development. Endocrine Society Forum on Endocrine-Disrupting Chemicals, San Diego, CA.
   


9. Dickerson SM, Walker DM, Steinberg RM, Dangleben NL, Gore AC (2005) Mechanisms for Aroclor 1221 actions on GnRH development. SETAC South Central Regional Meeting, Marble Falls, TX.
   


10. Dickerson SM, Reveron ME, Walker DM, Duvauchelle CL, Gore AC (2006) MDMA disrupts the reproductive axis in male rats. Endocrine Society, Boston, MA.
    


11. Maffucci JA, Walker DM, Makos B, Woller MJ, Gore AC (2006) The NMDA receptor subunit NR2b affects GnRH gene expression and LH release in female rats, with modulation by estrogen but not aging. Endocrine Society, Boston, MA.
    


12. Steinberg RM, Walker DM, Juenger T, Gore AC (2006) Prenatal PCBs induce altered gene expression in the preoptic area of the female rat. Endocrine Society, Boston, MA.
    


13. Walker DM, Gore AC (2007) Neuroendocrine gene expression In the preoptic area in male rats: Effects of development and castration. Endocrine Society, Toronto ON.
    


14. Walker DM, Perez LF, Gore AC (2008) Sex differences in neuroendocrine gene expression in the preoptic area (POA) throughout development. Endocrine Society, San Francisco, CA.
    


15. Perez LF, Walker DM, Gore AC (2008) Neuroendocrine gene expression in the medial basal hypothalamus (MBH) throughout postnatal development, Endocrine Society, San Francisco, CA.