Mathematical Biology Seminar
Department of Mathematical Sciences

New Jersey Institute of Technology

Fall 2014

All seminars are 11:40-12:40, in Cullimore Hall Room 611 (Math Conference Room) unless noted otherwise.  If you have any questions about a particular seminar, please contact the person hosting the speaker. The Math Department also hosts a number of other seminars and colloquia which can be accessed here: DMS Seminar Listing

Date	Speaker and Title	Host
Tuesday September 16 11:30 AM	Horacio Rotstein- New Jersey Institute of Technology
Tuesday  September 23	No Seminar
Tuesday September 30	No Seminar
Tuesday October 7	No Seminar
Tuesday October 14	Dave Stanley - Boston University Circadian rhythms, epilepsy and synchrony: A series of computational  and experimental investigations	Casey Diekman
Tuesday October 21	Victor Matveev - NJIT Modeling cell calcium dynamics: challenges and open problems
Tuesday October 28	James Rankin - New York University Perceptual bistability in auditory learning	Casey
Tuesday November 4	Xiaojun Yu - Stevens Institute of Technology Tissue Engineering for Peripheral Nerve Regeneration	Amit
Tuesday November 11	Hugh Piggins- University of Manchester Extrinsic and intrinsic regulation of the brain’s circadian clock	Casey
Tuesday November 18	Society for Neuroscience Meeting - No Seminar
Tuesday November 25	No Seminar
Tuesday December 2 11:30 AM	No Seminar	.
Tuesday   December 9   11:30 AM	Tim O'Leary - Brandeis University	Farzan

Abstracts

Dave Stanley - Boston University

Circadian rhythms, epilepsy and synchrony: A series of computational and experimental investigations 

For over a century epileptic seizures have been known to cluster at specific times of the day, but the mechanisms underlying this daily periodicity are not understood. We analyzed 24-hour rhythms in continuous long-term EEG recordings obtained from rats with temporal lobe epilepsy. We observed that both spontaneous hippocampal EEG spikes (SPKs) and EEG rhythms oscillated with near 24-hour periods. Following injury by status epilepticus (SE), a persistent phase shift hours emerged in animals that later went on to develop chronic spontaneous seizures. Using a combination of biophysical computer modeling and MRI data analysis, we provide a mechanistic theory for how such a phase shift could emerge. We conclude by discussing how abnormal circadian regulation may contribute to the daily rhythms of epileptic seizures. Additional topics, time permitting, will include modeling of intrinsic neural noise and a dynamical systems approach to synchrony detection.

Victor Matveev - NJIT

Modeling cell calcium dynamics: challenges and open problems

Over the past 30 years, computational modeling of intracellular calcium (Ca2+) dynamics has contributed key insights to our understanding of complex dynamics underlying spatio-temporal Ca2+ signaling, supplanting experimental data obtained by optical Ca2+ imaging. In particular, early modeling has shown that Ca2+ remains highly localized within the so-called "nanodomains" created by the opening of individual Ca2+ channels, further reinforcing the importance of modeling to probe fine temporal and spatial scales that are beyond the reach of Ca2+ imaging techniques. Despite the wide use of Ca2+ modeling in the studies of Ca2+-dependent physiological processes, there are many open question and challenges in this field. We will discuss some of these challenges, in particular the relationship between the two competing approaches to modeling Ca2+ dynamics: the continuous deterministic reaction-diffusion description and the stochastic simulations of Ca2+ ion movement combining stochastic brownian motion and stochastic reaction algorithms. We will also discuss novel analytic approximations describing the stationary distribution of Ca2+ within a single-channel nanodomain, which go beyond previously obtained asymptotic approximations that are valid in specific parameter regimes.

James Rankin - New York University

Perceptual bistability in auditory streaming

Perceptual bistability leads to spontaneous switches between competing interpretations of ambiguous sensory input. In auditory bistable perception sequences of alternating high and low tones can be perceived as grouped in a single rhythm or as split into separate streams. We present a physiologically motivated, low dimensional dynamical model with periodic input that takes into account mechanisms of mutual inhibition, slow adaptation and noise. The perceptual organisation for auditory perception in terms of stimulus parameters is captured; other model parameters are further constrained to match data from ongoing psychoacoustic experiments. Our model can account
for important differences between stimulus strength manipulations and attention that could generalise across sensory modalities. We propose further experiments to test our predictions.


Xiaojun Yu -Stevens Institute of Technologyes Rankin - New York University

Tissue engineering for peripheral nerve regeneration

Although many approaches have been examined for enhancing peripheral nerve regeneration, none have performed better than autograft procedures, the 'gold standard' for repairing peripheral nerve injuries. In particular, the treatment of peripheral nerve injuries involving large nerve gap is still challenging. Due to the inherent limitations of using autografts, tissue engineering has emerged as a powerful tool for developing viable alternative nerve grafts for peripheral nerve regeneration. In this talk, several tissue engineering strategies for promoting peripheral nerve regeneration will be discussed. The focus will be on novel structured nanofibrous nerve conduit that can meet the mechanical and nutrient transport requirements and provide directional guidance and augmented surface areas for enhancing cell invasion and peripheral nerve regeneration, and bioactive nanofibrous nerve conduits functionalized with extracellular matrix molecules and neurotrophic factors. Moreover, due to the abundance of variables that exist in tissue engineered nerve graft construction and multiple assessment types, there has been limited success in comparing nerve graft effectiveness among experiments. Another focus of the talk is on describing a new normalization technique based on nerve conduction velocity data from autografts. This technique allows for comparing the effectiveness of various tissue engineered nerve grafts, and further improving the design of tissue engineered nerve grafts for peripheral nerve regeneration.


Hugh Piggins - University of Manchester

Extrinsic and intrinsic regulation of the brain’s circadian clock

Endogenous daily or circadian rhythms in physiology and behavior emerge through the coordinated activity of thousands of clock cells in the brain’s suprachiasmatic nuclei (SCN) and the synchronization of the SCN to the recurrent signals in the external world. SCN clock cells contain an intracellular molecular clock that drives daily changes in neuronal activity, enabling the clock cells to communicate with one another and for the SCN to convey circadian time cues to the rest of the brain and body.  In this talk, I will report on recent studies examining how impairments in intercellular communication and the molecular clock affect SCN neuronal activity. Further, the utility of physical exercise as a stimulus to improve SCN clock function will be explored.