In our research we use the model organism C. elegans, a free-living soil based roundworm. Dr. Portman's lab uses several approaches, including a novel technique to sex-reverse the nervous system of our worms, to study the above questions. Former students and post-docs in the lab have investigated sex differences in olfaction and locomotion. Currently, we are working on understanding a sex difference in exploration. Males explore to a much greater extent than do hermaphrodites in this species. We find that the difference in exploration can be traced to a single gene product, expressed in a single pair of sensory neurons in C. elegans hermaphrodites. Forcing the expression of this gene in males, or sex reversing the nervous system can lead to hermaphrodite-like behavior in male worms. We are currently investigating the link between this gene and food sensation as well as what kind of evolutionary advantage this sex difference confers upon C. elegans males.
Additional projects I am pursuing with Dr. Portman include the investigation of a male-specific neuropeptide, FLP-23. Males lacking the flp-23 gene have behavioral deficits that may be traceable to developmental abnormalities in gonad morphogenesis. We are also using the CRISPR/Cas9 system to generate mutations in candidate receptors for FLP-23 in order to better understand the molecular signal transduction required for male specific behaviors and development. All of these projects ultimately help us to understand how sex differences in the brain are generated and regulated, what the physical substrates of the differences are, and how such differences interact with environmental stimuli to produce unique behavioral outputs and differential disease susceptibility.
- NSCI 201P: Basic Lab in Neurobiology
- NSCI 301: Senior Seminar
- BCSC 204: Lab in Cognitive Neuroscience
- NSCI/BCSC 243: Neurochemical Foundations of Behavior
- NSCI/BCSC 244: Neuroethology
- NSCI/BCSC 246: Biology of Mental Disorders
- DA Ryan, RM Miller, KH Lee, S Neal, K Fagan, P Sengupta and DS Portman. Sex, age and hunger regulate behavioral prioritization through dynamic modulation of chemoreceptor expression. Curr Biol. 2014 Nov 3;24(21):2509-17.
- RM Miller. Cognitive Bias in Fantasy Sports: Is your brain sabotaging your team? Xlibris Press, May 31, 2013. ASIN: B00D75PX1G
- Siehr MS, Koo PK, Sherlekar AL, Bian X, Bunkers MR, Miller RM, Portman DS, Lints R. Multiple doublesex-related genes specify critical cell fates in a C. elegans male neural circuit. Plos One. 2011;6(11):e26811.
- Miller, RM and Portman, DS. Wnt-directed asymmetry of the bHLH factor LIN-32 controls cell fate specification in sensory rays of C. elegans. (2011) J. Neurosci. Sep 14;31(37):13281-91.
- Zheng, B, Liao, Z, Locascio, JJ, Eklund, AC, Hauser, MA, Grunblatt, E, Moran, LB, Mandel, SA, Riederer, P, Miller, RM, Federoff, HJ, Wullner, U, Papapetropoulos, S, Youdim, MB, Cantuti-Castelvetri, I, Young, AB, Vance, JM, Davis, RL, Hedreen, JC, Adler, CH, Beach, TG, Graeber, MB, Middleton, FA, Rochet, J-C, and Scherzer, CR for the Global PD Gene Expression (GPEX) Consortium. (2010) PGC-1a, a potential therapeutic target for early intervention in Parkinson’s disease. Science Transl Med 2(52):52ra73.
- Hurd, DD*, Miller, RM*, Nunez, LB, and Portman, DS. (2010) Specific a- and b-tubulin isotypes optimize the functions of sensory cilia in Caenorhabditis elegans. Genetics 185(3):883-96.
- Miller, RM and Portman, DS. (2010) A latent capacity of the C. elegans polycystins to disrupt sensory transduction is repressed by the single-pass ciliary membrane protein CWP-5. Dis Model Mech. 3(7-8):441-50.
- Miller, RM and Federoff, HJ. (2008) Isoform specific effects of Apo E on HSV immediate early gene expression and establishment of latency. Neurobiol. Aging. 29(1):71-77.
- Miller, RM, Kiser, GL, Kaysser-Kranich, TM, Casaceli, C, Colla, E, Lee, MK, Palaniappan, C, and Federoff, HJ. (2007) Wild-type and mutant a-synuclein induce a multi-component gene expression profile consistent with shared pathophysiology in different transgenic mouse models of PD. Exp. Neurol. 204(1):421-432.
- Miller, RM, Kiser, GL, Kaysser-Kranich, TM, Sendera, TJ, Palaniappan, C, and Federoff, HJ. (2006) Robust dysregulation of gene expression in substantia nigra and striatum in Parkinson’s disease. Neurobiol. Dis. 21(2):305-313.
- Miller, RM, Chen, LL, Kiser, GL, Giesler, TL, Kaysser-Kranich, TM, Palaniappan, C, and Federoff, HJ. (2005) Temporal evolution of mouse striatal gene expression following MPTP injury. Neurobiol. Aging. 26(5):765-775.
- Miller, RM, Callahan, LM, Kiser, GL, Casaceli, C, Chen L, Chui B, Kaysser-Kranich, TM, Sendera, TJ, Palaniappan, C, and Federoff, HJ. (2004) Dysregulation of gene expression in the MPTP-treated mouse substantia nigra. J Neurosci. 24(34):7445-7454.