Urban Lab Department of Biological Sciences and Center for the Neural Basis of Cognition at Carnegie Mellon University

4400 Fifth Ave Mellon Institute
Pittsburgh PA 15213


Book Chapter
“Dendritic Neurotransmitter Release” in Dendrites, Stuart, Spruston and Häusser eds.  Oxford University Press 2nd edition.2007.

Journal Articles Published or In Press

  • Ermentrout GB, Galán, R.F, Urban NN. (2007) Relating neural dynamics to neural coding. Physical Review Letters. Physical Review Letters. 99. 248103.
    • Faculty of 1000 Must Read. In this paper we demonstrate that the two major approaches to understanding neural computation - neural dynamics and neural coding - are in fact closely related.  Specifically, we provide an analytic proof that the phase resetting curve of nonlinear dynamics can be easily computed from the spike triggered averaged used in analysis of neural coding and vice versa.  This work provides an important connection between these approaches and will allow for simple transitions from questions about coding to questions about dynamics and even biophysics.  This approach also may be applied to the interpretation of dynamics in non-neuronal oscillating systems.
  • Galán, R.F, Ermentrout GB, Urban NN. (2007) Stochastic dynamics of uncoupled neural oscillators: Fokker Planck studies with the finite element method. Physical Review E. 76 DOI: 10.1103/PhysRevE.76.056110
    • This paper describes how a powerful numerical tool - the finite element method - can be applied to solve problems relating to neuronal synchrony.
  • Galán, R.F, Ermentrout GB, Urban NN. (2007) Optimal time scale for spike-time reliability: Theory, simulations and experiments. J Neurophysiol. 2007 Oct 10; [Epub ahead of print]
    • This paper provides a detailed analysis of the dependence of spike time reliability on the time scale and the amplitude of fluctuating current injection.
  • Bagley, J, LaRocca, G, Jimenez, DA, and Urban, NN. (2007) Adult neurogenesis and specific replacement of interneuron subtypes in the mouse main olfactory bulb.  BMC Neuroscience. 2007 Nov 9;8(1):92.
    • Highly Accessed BMC This paper describes the fate of adult-born neurons in the olfactory bulb and shows that the fates chosen by new neurons migrating into the olfactory bulb closely reflects the distribution of existing interneuron subtypes in this structure.
  • Castro JB, Hovis KR, Urban NN. (2007)  Recurrent dendrodendritic inhibition of accessory olfactory bulb mitral cells requires activation of group I metabotropic glutamate receptors.  J. Neurosci. 27(21):5664-71.
  • Galán,R.F. Ermentrout, G.B. and Urban, N.N. (2007). Reliability and stochastic synchronization in type I vs. type II neural oscillators. Neurocomputing, 70: 2102-2106
  • Kapoor V. and Urban N.N., (2006) Glomerulus-specific, long latency activity in the olfactory bulb granule-cell network.  J. Neuroscience.  26(45):11709-19. 
    • Faculty of 1000 Recommended. This paper shows that activity of olfactory bulb granule cells occurs at latencies of up to 1000 ms after mitral cell activity. These long latencies are highly reliable from trial to trial and are input specific. We go on to show that mitral cells receive long latency inhibitory inputs that are as reliable as the granule cell spikes, and that granule cell activity is effective at generating specific patterns of spiking in the mitral cells projecting to olfactory cortex.  We suggest that these long-latency events may be critical for generating the slow temporal structure of mitral cell activity seen in vivo.
  • Egger, V and Urban N.N. (2006) Dynamic lateral inhibition in the mitral cell-granule cell microcircuit.  Seminars in Cell and Developmental Biology 17(4):424-32.
  • Galán,R.F. Ermentrout, G.B. and Urban, N.N.  (2006). Reliability, discriminability and noise-induced synchronization of olfactory neurons. Sensors and Actuators B: Chemical.  116(1-2), p.168-173.
  • Galán, R.F.,  Ermentrout, G.B. and Urban N.N. (2006). Predicting synchronized neural assemblies from experimentally estimated phase-resetting curves. Neurocomputing, 69(10-12), p.1112-1115.
  • Galán, R.F., Fourcaud-Trocme, N., Ermentrout, G.B. and Urban N.N. (2006). Correlation-induced synchronization of oscillations in olfactory bulb neurons. J. Neuroscience, 26(14):3646-55.
    • This paper demonstrates the constructive effects of correlated noise in generating synchronous neuronal oscillations. We also argue that this noise-induced oscillatory synchronization accounts for fast oscillatory synchronization in the olfactory bulb. Similar forms of noise-induced synchronization have been proposed in the theoretical literature and may account for a variety of biological phenomenon.
  • Fernández Galán, R. Ermentrout, G.B. and Urban, N.N. (2005 ) Efficient estimation of phase-resetting curves in real neurons and its significance for neural-network modeling.  Phys Rev Lett. Apr 22;94(15):158101. 
    • This paper describes a novel method for estimating the phase resetting curve of a neuron. The phase resetting curve is a highly reduced description of the dynamics of a firing neuron that allows the synchronization and coding properties of that neuron to be predicted.
    • This work was chosen by Scientific American as one of fifty emerging trends in research, business and policy in 2005: “Watching the brain at work" by Michael Szpir, Scientific American, December 2005, p.62. [PDF article]
    • Also see: "Fearful symmetry: Probing the limits of brain modeling", by Fred Hapgood, Cerebrum, the Dana forum on brain science, Vol. 7(3),Summer 2005.
    • "Carnegie Mellon and U. of Pittsburgh create tool to understand neuron rhythms, learning. Work will aid neural-network modeling, studies of learning and disease", by Lauren Ward, EurekAlert!, April 11, 2005.
  • Castro J. and Urban, N.N. (2005) Tuft calcium spikes in accessory olfactory bulb mitral cells.  J Neurosci. 25(20):5024-8.
    • This paper provides the first description of the biophysical properties of dendrites of accessory olfactory bulb mitral cells. These biophysical properties combine to make these cells function as “neuronal electoral colleges”.  Each dendritic tuft has a local threshold, and contributes to the initiation of somatic action potentials in an all-or-none fashion, effectively casting one “vote” for a somatic action potential.  In turn, a somatic action potential is generated only when a certain fraction of tufts vote in favor of spiking. 
  • Gonzalez-Burgos G, Krimer L.S., Urban N.N., Barrionuevo G., Lewis D.A. (2004)  Synaptic efficacy during repetitive activation of excitatory inputs in primate dorsolateral prefrontal cortex.  Cereb Cortex. 2004 May;14(5):530-42.
  • Schoppa, N.S. and Urban, N. N.  (2003) Dendritic processing within olfactory bulb circuits.  Sep;26(9):501-6. Trends in Neurosciences.
  • Urban, N.N.  (2002)  Lateral inhibition in the olfactory bulb and in olfaction.  Physiol Behav. Dec;77(4-5):607-12.
  • Gonzalez-Burgos G, Kroner S, Krimer L.S., Seamans J.K., Urban N.N., Henze D.A., Lewis D.A., Barrionuevo G.  (2002)  Dopamine modulation of neuronal function in the monkey prefrontal cortex.  Physiol Behav.  77(4-5):537-43.
  • Urban, N.N. and Sakmann, B.  (2002) Reciprocal intraglomerular excitation and intra and interglomerular lateral inhibition between olfactory bulb mitral cells.  J. Physiology. 542.2: 355-367.
  • Urban N.N., Gonzalez-Burgos G., Henze D.A., Lewis D.A., Barrionuevo G.  (2002)  Selective reduction by dopamine of excitatory synaptic inputs to pyramidal neurons in primate prefrontal cortex.  J Physiol. 539(Pt 3):707-12.
  • Margrie, T.W. Sakmann, B. Urban, N.N. (2001)  Action potential propagation in mitral cell lateral dendrites is decremental and controls recurrent and lateral inhibition in the mammalian olfactory bulb. PNAS, Vol. 98, Issue 1, 319-324.
  • Urban, N.N., Henze, D.A. and Barrionuevo, G. Revisiting the role of the hippocampal mossy fiber synapse.  Hippocampus.  11(4):408-17.
  • Henze, D.A., González-Burgos, G., Urban, N.N., Lewis, D.A., and Barrionuevo, G..  (2000) Dopamine increases excitability of pyramidal neurons in primate prefrontal cortex. J Neurophysiol. 84(6):2799-809.
  • Thiels, E., Urban, N.N., Gonzales-Burgos, G.R., Kanterewicz, B.I., Barrionuevo, G., Chu, C.T., Oury, T.D. and Klann, E. (2000) Impairment of long-term potentiation and associative memory in mice that overexpress extracellular superoxide dismutase. Journal of Neuroscience. 20: 7631-7639
  • Kanterewicz*, B. I., Urban*, N. N., McMahon, D. B. T., Norman, E.  D., Giffen, L. J., Favata, M. F., Scherle, P. A., Barrionuevo, G., and Klann, E. (2000)  The Extracellular Signal-Regulated Kinase Cascade Is Required for NMDA Receptor-Independent LTP in Area CA1 But Not Area CA3 of the Hippocampus.  J. Neuroscience. 20: 3057-3066. *indicates that these authors contributed equally to this work
  • Henze, D.A. Urban, N.N., and Barrionuevo, G.  (2000) The mulitfarious hippocampal mosy fiber pathway: a review. Neuroscience. 98:407-427
  • Urban, N.N., and Barrionuevo, G. (1998) Active summation of excitatory postsynaptic potentials in hippocampal CA3 pyramidal neurons. PNAS. 95(19):11450-5.
  • Urban, N.N., Henze, D.A., and Barrionuevo, G. (1998) Amplification of perforant-path EPSPs in CA3 pyramidal cells by LVA calcium and sodium channels. J Neurophysiol. 80(3):1558-61.
  • Berzhanskaya, J. Urban, N.N. and Barrionuevo, G. (1998) Electrophysiological and pharmacological characterization of the direct perforant path input to hippocampal area CA3. J Neurophysiol. 79(4):2111-8.
  • Henze, D.A., Urban, N.N., and Barrionuevo., G. (1997) Origin of the apparent asynchronous activity of hippocampal mossy fibers. J Neurophysiol. 78: 24-30.
  • Urban, N.N., Henze, D.A., Lewis, D.A., and Barrionuevo, G. (1996) Properties of LTP induction in area CA3 of the primate hippocampus. Learning and Memory 3:86-95.
  • Urban N.N., Barrionuevo G. (1996) Induction of Hebbian and non-Hebbian LTP at the hippocampal mossy fiber synapse by distinct patterns of high frequency stimulation. J Neurosci. 16(13): 4293-4299.
  • Chinestra P., Diabira D., Urban N.N., Barrionuevo G., Ben-Ari Y. (1994) Major differences between long-term potentiation and ACPD-induced slow-onset potentiation in hippocampus. Neuroscience Letters 182:177-180.
  • Coon, D.D., Sorar, E., Bandara, K.M.S.V., Urban, N. (1991) New degrees of freedom in resonant tunneling heterostructure devices. Journal of Applied Physics, 69(1):4344-8.