Julie S. Haas, Ph.D.
Department of Biological Sciences
Iacocca Hall, Room D226
111 Research Drive
Bethlehem, PA 18015
Dr. Haas's research is funded by the Brain & Behavior Foundation and the Whitehall Foundation.
- Positions Available
Our research is focused on electrical synapses. Formed by pores that connect the cytoplasm of coupled cells, these synapses allow ions and information to flow directly between neurons.
We are interested in determining the relationships between electrical synaptic strength, synchrony in circuits of coupled neurons, and the more abstract process of attention. These ideas coalesce within the thalamus, in a specific nucleus where electrical synapses are particularly dense; it is this nucleus that is thought to gate cortical attention to the sensory surround. I hypothesize that the strength of electrical synapses within this nucleus is a crucial component for the control of human attention.
To study electrical synapses, our main tool is dual whole-cell patch clamping. In the image above, two electrode tips are shown in preparation for patching the two cell bodies, which are connected by an electrical synapse (also known as a gap junction) where the ‘arms’ of the two neurons cross.
|The Haas Lab - 2014
(l-r) Jessica Sevetson (Lab Technician); Undergraduate Researchers: Sarah Fittro, Emily Heckman, Bijal Desai; Julie Haas, Ph.D., Principal Investigator
Haas JS (2015). A new measure for the strength of electrical synapses. Front. Cell. Neurosci. 9:378. doi: 10.3389/fncel.2015.00378.
Sevetson J and Haas JS (2014). Asymmetry and modulation of spike timing in electrically coupled neurons. J. Neurophysiol. doi: 10.1152/jn.00843.2014.
Vogels TP, Froemke R, Doyon N, Gilson M, Haas JS, Liu R, Maffei A, Miller P, Wierenga P, Woodin M, Zenke F and Sprekeler H (2013). Inhibitory synaptic plasticity: Spike-timing dependence and putative network function. Frontiers in Neural Circuits 7:119.
Haas JS and Landisman CE (2012) Bursts modify electrical synaptic strength. Brain Research, special issue on Electrical Synapses, in press.
Haas JS, Zavala B and Landisman CE (2011) Activity-dependent long-term depression of electrical synapses.
Haas JS and Landisman CE (2011) State-dependent modulation of gap junction signaling by the persistent sodium current. Frontiers in Cellular Neuroscience 5:31.
Haas JS, Kreuz T, Torcini A, Politi A, Abarbanel HDI (2010) Rate maintenance in spiking neurons driving with strong inputs of varying speeds. European Journal of Neuroscience 32(11):1930-9.
Kreuz T, Chicharro D, Andrzejak RG, Haas JS, Abarbanel HDI, Politi A (2009). Measuring multiple spike train synchrony. J. Neurosci. Methods 182(2):287-299.
Kreuz T, Haas JS, Morelli A, Abarbanel HDI, Politi A (2007). Measuring spike train synchrony. J. Neurosci. Methods 165(1):151-61.
Haas JS, Dorval AD, White JA (2007). Contributions of Ih to feature selectivity in layer II stellate cells of the entorhinal cortex. J. Computational Neuroscience 22(2):161-71.
Haas JS, Nowotny TN, Abarbanel HDI (2006). Spike-timing-dependent plasticity at inhibitory synapses in the entorhinal cortex. J. Neurophysiol 96: 3305-3313.
Netoff TI, Banks MI, Dorval AD, Acker CD, Haas JS, Kopell N, White JA (2004). Synchronization in hybrid neuronal networks of the hippocampal formation. J. Neurophysiol. 93(3):1197-1208.
Haas JS and White JA (2002). Frequency selectivity of layer II stellate cells in the medial entorhinal cortex.
J. Neurophysiol. 88(5): 2422-2429.
Abarbanel HDI, Haas JS, Talathi SS (2007) Synapses and neurons: Basic properties and their use in the recognition of environmental signals. In Lecture Notes in Supercomputational Neuroscience, Springer-Verlag.
White JA and Haas JS (2001) Noise from voltage-gated ion channels: effects on dynamics and reliability in intrinsically oscillatory neurons. In Handbook of Biological Physics, Vol. 4, F Moss and S Gielen (eds.), Elsevier Press, Amsterdam.
We seek a postdoctoral researcher who is highly motivated to study the plasticity of electrical synapses in mammalian brain slices using electrophysiological and optogenetic approaches, under the direction of Dr. Julie Haas. Our work relies on a combination of techniques, including dual-cell recordings in vitro, quantitative analyses, computational modeling and histology. Prior experience with in vitro electrophysiology, optogenetic methods and proficiency in MATLAB is highly desirable. Located proximally to NYC and Philadelphia, the Lehigh community provides an ambitious, supportive and collaborative research environment, and offers excellent training and career development opportunities.
Interested candidates should send their CV, a brief cover letter indicating your research interests and goals, and the names and contact information for three professional references to Dr. Julie Haas
Appointment is a renewable one-year contract at the appropriate NIH salary scale.