Neural Dynamics

Patrick David Roberts
Washington State University, Vancouver
Systems Science Program, Portland State University
Biomedical Engineering, Department of Science & Engineering, Oregon Health Sciences University,
e-mail: robertpa@ohsu.edu

Current CV

PRESENT RESEARCH INTERESTS (detailed description)
To develop appropriate mathematical methods, both analytical and computational, to study the dynamics of neural activity patterns, and to help understand the relationship between these dynamics and behavior. Using mathematical methods drawn from statistical physics and dynamical systems, the specific areas of research are as follows:

Computational Pharmacology: Given that many biological mechanisms of schizophrenia are now understood, and that computational power and technique has reached the point for practical modeling of pathologies of schizophrenia, In Silico Biosciences, Inc is developing a computational platform to bridge the gap from pre-clinical and clinical trials. Computational models can combine the information from animal studies of brain circuitry with data from human clinical trials of drug actions. Furthermore, complex interactions of multiple receptor targets can be predicted by a biophysical model of brain function. We develop computational models of neural micro-circuits to predict the efficacy of drug actions on symptoms of mental diseases such as schizophrenia.
The storage of temporal patterns in cerebellum-like structures: We are investigating the dynamics of synaptic plasticity at the site of initial electrosensory information processing in mormyrid electric fish and mammalian dorsal cochlear nucleus. Using mathematical analyses and computer simulations, results from different experiments performed in electrophysiology labs are combined to predict changes in responses of neurons during changing sensory conditions (Click here for an introduction to the electrosensory system and spike-timing dependent plasticity presented at CNS*00 meeting, Brugge, Belgium).
Dynamics of neural activity in the auditory system: This collaborative projects investigated various hypothetical mechanisms underlying neuronal activity patterns in the auditroy pathways of the brainstem and midbrain. The modeling effort will help to bridge the gap between cellular- and systems-level experimental findings.
Biological learning rules: A research program is presently underway to analyze the neural dynamics that result from different biological learning rules. Since the timing relations of biological learning rules result from molecular events at the synapse, this line of research helps to link the implications of dynamics at the molecular level, through dynamics at the network level, to the behavior of whole organisms.

PUBLICATIONS
H. Geerts and A. Spiros and P. Roberts and S Potkin (2015) Understanding responder neu- robiology in schizophrenia using a quantitative systems pharmacology model: Application to iloperidone. J Psychopharmacol. [Epub ahead of print]

T. Nicholas , S. Duvvuri, C. Leurent, D. Raunig, T. Rapp, P. Iredale, C. Rowinski , R. Carr , P. Roberts, A. Spiros and H. Geerts (2013) Systems pharmacology modeling in neuroscience: Prediction and outcome of PF-04995274, a 5-HT4 partial agonist, in a clinical scopolamine impairment trial. Advances in Alzheimer’s Disease 2: 83-98.

A. Spiros, P. Roberts, H. Geerts (2013) Phenotypic screening of the Prestwick library for treat- ment of Parkinson’s tremor symptoms using a humanized quantitative systems pharmacology platform. J Parkinsons Dis 3: 569-580.

C.V. Portfors and P.D. Roberts (2014) Mismatch of structural and functional tonotopy for natural sounds in the auditory midbrain. Neuroscience 258: 192-203.

J. Liu, A. Ogden, T. A. Comery, A. Spiros and P. Roberts and H. Geerts (2014) Prediction of Efficacy of Vabicaserin, a 5-HT2C Agonist, for the Treatment of Schizophrenia Using a Quantitative Systems Pharmacology Model. CPT Pharmacometrics Syst. Pharmacol. 3: e111

H. Geerts, P. Roberts, A. Spiros (2013) A quantitative system pharmacology computer model for cognitive deficits in schizophrenia. CPT: Pharmacometrics & Systems Pharmacology 2: e36.

H. Geerts, A. Spiros, P. D. Roberts, and R. Carr (2013) Quantitative systems pharmacology as an extension of PK/PD modeling in CNS research and development. J Pharmacokinet Pharmacodyn [Epub ahead of print].

H. Geerts, P. D. Roberts, A. Spiros, and R. Carr (2013) A strategy for developing new treatment paradigms for neuropsychiatric and neurocognitive symptoms in Alzheimers disease. Frontiers in Pharmacology 4: 47.

A. Spiros, P. Roberts, H. Geerts (2012) A quantitative systems pharmacology computer model for schizophrenia efficacy and extrapyramidal side effects, Drug Dev Res 73: 1098-1109.

Z. Mayko, P. Roberts, and C. Portfors (2012) Inhibition shapes selectivity to vocalizations in the inferior colliculus of awake mice. Frontiers in Neural Circuits, 6: 73.

H. Geerts, A. Spiros, P. D. Roberts, and R. Carr (2012) Has the time come for predictive com- puter modeling in CNS drug discovery and development? CPT: Pharmacometrics & Systems Pharmacology, 1: e16.

P. D. Roberts, H. Geerts, and A. Spiros (2012) Simulations of symptomatic treatments for Alzheimers disease: Computational analysis of pathology and mechanisms of drug action. Alzheimer’s Research & Therapy, 4: 50.

H. Geerts, A. Spiros, P. Roberts, R. Twyman, L. Alphs, and A. A. Grace (2012) Blinded prospective evaluation of computer-based mechanistic schizophrenia disease model for predicting drug response. PLOS One 7: e49732.

C.V. Portfors, Z.M. Mayko, K Jonson, G.F. Cha, P.D. Roberts (2011) Spatial organization of receptive fields in the auditory midbrain of awake mouse. Neuroscience. 193: 429-39. (PDF)

L. Holmstrom, L.B.M. Eeuwes, P.D. Roberts, C.V. Portfors (2010) Efficient Encoding of Vocalizations in the Auditory Midbrain. J Neurosci 30: 802-819. (PDF)

P.D. Roberts and T.K. Leen (2010) Anti-Hebbian spike-timing-dependent plasticity and adaptive sensory processing. Front. Comput. Neurosci. 4:156. (PDF)

C.V. Portfors, P.D. Roberts (2009) Over-representation of species-specific vocalizations in the awake mouse inferior colliculus. Neuroscience 162: 486-500. (PDF)

V. Balakrishnan, S.P. Kuo, P.D. Roberts and L.O. Trussel (2009) Slow glycinergic transmission mediated by transmitter pooling. Nature Neuroscience 12: 286-294. (PDF)

P.D. Roberts, C.V. Portfors (2008) Design principles of sensory processing in cerebellum-like structures. Early stage processing of electrosensory and auditory objects. Biol Cybern. 98: 491-507. (PDF)

P.D. Roberts, R.A. Santiago, G. Lafferriere (2008) An implementation of reinforcement learning based on spike timing dependent plasticity. Biol Cybern. 99: 517523. (PDF)

L. Holmstrom, P.D. Roberts, C.V. Portfors (2007) Responses to Social Vocalizations in the Inferior Colliculus of the Mustached Bat are Influenced by Secondary Tuning Curves. J Neurophysiol 98: 3461-3472. (PDF)

C.V Portfors, P.D. Roberts (2007) Temporal and Frequency Characteristics of Cartwheel Cells in the Dorsal Cochlear Nucleus of the Awake Mouse. J Neurophysiol 98: 744-756. (PDF)

P.D. Roberts, R. Santiago, C. Mello, T. Velho (2007) Storage of Auditory Temporal Patterns in the Songbird Telencephalon. Neurocomputing 70: 2030-2034. (PDF)

O. Iancu, P.D. Roberts, J. Zhang, C.C. Bell (2007) Postsynaptic modulation of electrical EPSP size investigated using a compartmental model. Neurocomputing 70: 1685-1688. (PDF)

P.D. Roberts (2007) Stability of Complex Spike Timing-Dependent Plasticity in Cerebellar
Learning. J Compu Neurosci 22: 283-296.(PDF)

Sawtell NB, Williams A, Roberts PD, von der Emde G, Bell CC (2006) Effects of sensing behavior on a latency code. J Neurosci. 26:8221-34. (PDF)

P. D. Roberts, C.V. Portfors, N. Sawtell, and R. Felix (2006) Model of auditory prediction in the dorsal cochlear nucleus via spike-timing dependent plasticity. Neurocomputing, 69:1191–1194. (PDF)

P. D. Roberts, G. Lafferriere, N. Sawtell, A. Williams, C.C. Bell (2006) Dynamic regulation of spike-timing dependent plasticity in electrosensory processing. Neurocomputing, 69: 1195–1198. (PDF)

P. D. Roberts (2005) Recurrent neural network generates a basis for sensory image cancellation. Neurocomputing, 65-66: 237–242. (PDF)

C. V. Mello and P. D. Roberts (2005) Neuronal substrates of sensory processing for songperception and learning in songbirds: Lessons from the mormyrid electric fish. In J. S. Kanwaland G. Ehret, editors, Behavior and Neurodynamics for Auditory Communication, pp 265-293, Cambridge England, Cambridge University. (PDF)

McCollum G, Roberts PD (2004) Dynamics of everyday life: rigorous modular modeling in neurobiology based on Bloch's dynamical theorem. J Integr Neurosci. 3:397-413. (PDF)

Williams A, Leen TK, Roberts PD (2004) Random walks for spike-timing-dependent plasticity. Phys Rev E 70:021916 (PDF)

Roberts PD (2004) Recurrent biological neural networks: the weak and noisy limit. Phys Rev E 69:031910. (PDF)

Williams A., Roberts P.D., Leen, T.K.(2003) Stability of Negative Image Equilibria in Spike-Timing Dependent Plasticity, Phys. Rev. E 68, 021923 (arXiv.org:physics/0304062)

C. Mohr, P. D. Roberts, and C. C. Bell (2003) Cells of the mormyrid electrosensory lobe: I. Responses to the electric organ corollary discharge and to electrosensory stimuli. J. Neurophysiology 90: 1193-1210. (PDF)

C. Mohr, P. D. Roberts, and C. C. Bell (2003) Cells of the mormyrid electrosensory lobe: II. Responses to input from central sources. J. Neurophysiology 90: 1211-1223. (PDF)

Roberts PD (2003) Recurrent Biological Neural Networks: The Weak and Noisy Limit, (in press) Phys. Rev. E (arXiv.org:cond-mat/0305515) (PDF)

Roberts P. D. (2003) Effects of noise on recurrence in networks of spiking neurons. Neurocomputing 52-54:893-899. (PDF)

P. D. Roberts and C. C. Bell (2003) Active Control of Spike-Dependent Synaptic Plasticity inan Electrosensory System. J.Physiol. (Paris), 96: 445-449. (PDF)

P. D. Roberts and C. C. Bell (2002) Spike-Timing Dependant Synaptic Plasticity: Mechanisms and Implications. Biol. Cybern. 87, 392–403. (PDF) (The original publication is available at http://link.springer.de or at http://link.springerny.com.)

P. D. Roberts and C. C. Bell (2001) Mutual Inhibition Increases Adaptation Rate in an Electrosensory System. Neurocomputing 38-40:845-850. (PDF)

PD Roberts (2001) Cooperative field theory is critical for embodiment, Beh. Brain Sci. 24:59-60 (PDF)

P. D. Roberts (2000) Modeling Inhibitory Plasticity in the Electrosensory System of Mormyrid Electric Fish. J. Neurophys.84: 2035-2047(PDF)

P. D. Roberts (2000) Dynamics of temporal learning rules. Phys. Rev. E 62: 4077-4082 (PDF)

P. D. Roberts (2000) Electrosensory response mechanisms in mormyrid electric fish. Neurocomputing 32-33:243-248. (PDF)

P. D. Roberts and C. C. Bell (2000) Computational consequences of temporally asymmetric learning rules: II. Sensory image cancellation. J. Compu. Neurosci. 7: 67-83. (PDF)

P. D. Roberts (1999) Computational consequences of temporally asymmetric learning rules: I. Differential Hebbian learning. J. Compu. Neurosci. 7: 235-246. (PDF)

P. D. Roberts (1998) Rhythmic behavior generated by neural ensembles. Int. J. Theor Phys. 37: 3051-3068. (PDF)

P. D. Roberts (1998) Classification of temporal patterns in dynamic biological networks, Neural Comp. 10: 1831-1846. (PDF)

P. D. Roberts (1997) Stochastic recruitment in parallel fiber activity patterns. Beh. Brain Sci. 20: 263-264. (PDF)

P. D. Roberts (1997) Classification of temporal patterns in the stomatogastric ganglion, Neuroscience 81: 281-296. (PDF)

P. D. Roberts, G. McCollum, and J. E. Holly (1996) Cerebellar rhythms: Exploring another metaphor, Beh. Brain Sci. 19: 146-147. (PDF)

P. D. Roberts and G. McCollum (1996) The stomatogastric nervous system: A formal approach, Neuroscience 72: 1089-1105. (PDF)

P. D. Roberts and G. McCollum (1996) Dynamics of the sit-to-stand movement, Biol. Cybern. 74: 147-157. (PDF)

String Theory Publications:
S. Hwang and P. Roberts (1993) Interaction and modular invariance of strings on curved manifolds, In Pathways to Fundemental Theories L. Brink and R. Marnelius (eds.) World Scientific, Singapore, pp. 61-75. (LaTex version)

P. Roberts and H. Terao (1992) Modular invariants of Kac-Moody algebras from covariant lattices, Int. Jour. of Mod. Phys. A7: 2207-2218. (LaTex version, references)

M. Henningson, S. Hwang, P. Roberts and B. Sundborg1 (1991) Modular invariance of SU(1,1) strings, Phys. Lett. B267: 350-355. (LaTex version)

P. Roberts, (1990) Modular invariant partition functions of minimal models from self-dual lattices, Phys. Lett. B244: 429-434. (LaTex version, references)

B.E.W. Nilsson, P. Roberts and P. Salomonson (1989) Standard model-like string theories from covariant lattices, Phys. Lett. B222: 35-42. (LaTex version, references)

P.D. Roberts and C.C. Bell (2000) Electrosensory response mechanisms in mormyrid electric fish. Featured presentation at Ninth Annual Computational Neuroscience Meeting, Brugge, Belgium. (presentation)

P.D. Roberts (1999) Electrosensory response mechanisms in mormyrid electric fish. Presented at Eighth Annual Computational Neuroscience Meeting, CNS*99, Pittsburgh, PA.

P.D. Roberts (1999) Dynamics of temporal learning rules in adaptive biological networks. Presented at the American Physical Society Centennial Meeting, Atlanta, GA.

P.D. Roberts and C.C. Bell (1998) Consequences of temporal order in synaptic plasticity. Presented at the Electroreception and Electrocommunication, San Diego, CA.

P.D. Roberts and C.C. Bell (1997) Computational consequences of temporal order in synaptic plasticity. Presented at the Dynamical Neuroscience Satellite Symposium , New Orleans, LA.(poster)

P.D. Roberts (1996) Rhythms in dynamic biological networks. Presented at the Society for Mathematical Biology Annual Meeting, Seattle, WA.

P.D. Roberts and G. McCollum (1995) Temporal pattern generation in dynamic biological networks, Soc. Neurosci. Abstr. 21(1): 225.

P. Roberts and G. McCollum (1994) A formal approach to the function and behavior of the stomatogastric nervous system, Soc. Neurosci. Abstr. 20(1): 324. (poster)

P. Roberts and G. McCollum (1993) The dynamics of rising from a seated position, Soc. Neurosci. Abstr. 19(2): 1687. (poster)