The Interdisciplinary Biomedical Sciences Ph.D. Program

Big enough to be on the forefront of research

Small enough for one on one interactions with experts

We foster a cooperative climate for training and research that has an established record of timely graduations and alumni successes.  We also provide competitive stipends in a vibrant region with a low cost of living.

Featuring Yong-jie Xu Lab

The Xu lab studies the checkpoint mechanism that coordinates DNA replication with cell cycle progression. Various factors such as DNA damage and polymerase toxins can block DNA replication, which activates the checkpoint to slow down mitosis so that the cells can have enough time to properly finish the DNA synthesis before cell division. Progress in this research will advance our knowledge of the mechanisms that control cell proliferation and prevent oncogenesis. His lab also studies therapeutics identified from basic research for better treatment of cancer or infectious diseases.

Integrative Biology and Toxicology

Are you interested in studying the mammalian organism as an entire system or investigating a specific organ system as a part of the whole organism? If so, consider the Integrative Biology and Toxicology area of concentration.

Molecular Genetics and Cell Biology

Research training opportunities in the Molecular Genetics and Cell Biology area of concentration extend across the molecular, cellular, intercellular and organismal levels of biology.


Neuroscience and Physiology

The Neuroscience and Physiology area of concentration involves investigating the function of the cell, the organ and the whole animal, using molecular, cellular, physiological and behavioral approaches.

Structural and Quantitative Biology

Traditional biological research and computational science methods have come together to form the next wave in research. This combination is maximized in the Structural and Quantitative Biology area of concentration.

Research Spotlight

Ph.D. Candidate Amr Mahrous


Burst firing in motoneurons represents the basis for generating meaningful movements. Neuromodulators and inhibitory receptor blockers cocktails have been used for years to induce burst firing in vitro; however, the ionic mechanisms in the motoneuron membrane which contribute to burst initiation and amplitude modulation are not fully understood. Small conductance Ca2+-activated potassium channels (SK channels) regulate excitatory inputs and firing output of motoneurons and interneurons and, therefore, are a candidate for mediating bursting behavior. The present study examines the role of SK channels in the generation of synchronized bursting using an in vitro spinal cord preparation from adult mice. Our results show that SK channel inhibition is required for both initiation and amplitude modulation of burst firing. Specifically, administration of the synaptic inhibition blockers strychnine and picrotoxin amplified the spinal circuit excitatory drive but not enough to evoke bursting. However, when SK channels were inhibited using various approaches, the excitatory drive was further amplified and synchronized bursting was always evoked. Also, graded SK channel inhibition modulated the amplitude of the burst in a dose-dependent manner, which was reversed using SK channel activators. Importantly, modulation of neuronal excitability using multiple approaches failed to mimic the effects of SK modulators, suggesting a specific role for SK channel inhibition in generating bursting. Both NMDA and AMPA receptors were found to drive the synchronized bursts. Blocking gap junctions did not disturb the burst synchrony. These results demonstrate a novel mechanistic role for SK channels in initiating and modulating burst firing of spinal motoneurons. 

J Neurophysiol. 2017 Mar 29:jn.00929.2016. doi: 10.1152/jn.00929.2016. [Epub ahead of print]



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