Administration Basic Sciences Clinical Sciences Centers of Excellence
Department Title
Spotlight Section New Orleans
 

Jeffrey D. Erickson, PhD

Associate Professor of Pharmacology and Neuroscience
 

LSU Health Sciences Center
2020 Gravier St.
New Orleans, LA 70112

Phone: (504) 599-0845

Fax: (504) 599-0488

jerick@lsuhsc.edu

 

Left, The 'leaky bathtub' model of filling mammalian CNS synaptic vesicles is dependent upon transporter number and the cytoplasmic transmitter concentration. Right, Homeostatic regulation of the excitation-inhibition (E/I) balance in cortical networks, according to Turrigiano and Nelson (2004). Prolonged hyperactivity induces increases in excitatory synaptic strength onto GABAergic neurons (Red, via recurrent feed-back inhibition) and decreases in strength onto pyramidal neuronal dendrites (Blue, via feed-forward excitation). Our working model is that vesicular transporter isoforms for glutamate control quantal size and quantal content at discrete synapses to determine presynaptic strength and restore E/I balance.

URL: http://www.medschool.lsuhsc.edu/faculty/docs/Research Summary-Retreat, Erickson.pdf
Degrees

1987-1992: PhD (Genetics), George Washington University, Washington, DC
1982-1984: MSc (Pharmaceutical Sciences), University of Colorado, Boulder, CO
1975-1981: BA (Molecular, Cellular, and Developmental Biology), University of Colorado, Boulder, CO
Bio

2002-present: Associate Professor of Pharmacology and Neuroscience, Neuroscience Center of Excellence, LSU Health Sciences Center, New Orleans, LA

1997-2002: Assistant Professor of Pharmacology and Neuroscience,Neuroscience Center of Excellence, LSU Health Sciences Center, New Orleans, LA

1993-1997: Postdoc, Laboratory of Cell Biology, NIMH, Bethesda, MD

1984-1987: Guest Researcher, Department of Pharmacology, University of Colorado, Denver, CO

Awards/Honorary Lectures:

2006-2009: NARSAD Independent Investigator Award

2004: Minisymposium in tribute to Frode Fonnum: From Neuroanatomy to Neurochemistry. University of Oslo, Oslo, Norway, November 5, 2004 (Keynote speaker)

1998: LSUMC Neuroscience Center Excellence Award

1995: NIH Fellows Award for Research Excellence
Research Interests

Keywords:
synaptic vesicle transporter proteins
molecular and cellular biology of vesicular neurotransmitter transporters

Current Research:

Vesicular glutamate transporters in the regulation
of quantal size and synaptic vesicle release probability

Presynaptic mechanisms that contribute to quantal variance and synaptic plasticity are poorly understood. Recent work has established that, for mammalian cortical glutamatergic synaptic vesicles that express VGLUT1, quantal size is determined by the number of transporters per vesicle, and that this density is endogenously regulated both across development and by prolonged changes in activity of mature neural networks (Wilson et al., 2005). Furthermore, VGLUT1 and VIAAT are oppositely (and bi-directionally) regulated by prolonged changes in neural activity in vitro (De Gois et al., 2005). This indicates that mechanisms of homeostatic plasticity include regulation of vesicle filling with glutamate and GABA in a manner that serves to restore E/I balance (Erickson et al., 2006). We have also shown that VGLUT1 plays an unanticipated role in synapses; it interacts with adaptor proteins within axonal boutons that likely alter the availability of excitatory vesicles for release, at least compared to VGLUT2 or VGLUT3 (De Gois et al., 2006). We use primary cortical dissociated cultures, organotypic hippocampal slice cultures, in vivo knockout animals, yeast two-hybrid analyses, and biochemical procedures to further address these issues. Our current research focuses on the differential role for VGLUT1 and VGLUT2 isoforms in the mechanisms of presynaptic plasticity in developing and adult cortical neuronal circuits in vitro and in vivo.
Selected Publications

1. Grewal, S, DeFamie, N., Zhang, X., De Gois, S., Shawki, A., Mackenzie, B., Chen, C., Varoqui, H., and Erickson, J.D. (2009) SNAT2 amino acid transporter is regulated by amino acids of the SLC6 GABA transporter subfamily in neocortical neurons and may play no role in delivering glutamine for glutamatergic transmission. J. Biol. Chem., 284, 11224-11236.

2. Mackenzie, B., Illing, A.C., Morris, M.E.K., Varoqui, H., and Erickson, J.D. (2008) Analysis of a vesicular glutamate transporter (VGLUT2) supports a cell leakage mode in addition to vesicular packaging. Neurochem Res. 33, 238-247.

3. Burkhalter, J., Fiumelli, H, Erickson, J.D., and Martin, J.L. (2007) A critical role for system A amino acid transport in the regulation of dendritic development by BDNF. J. Biol. Chem. 282, 5152-5159.

4. De Gois, S., Jeanclos, E., Morris, M., Grewal, S., Varoqui, H., and Erickson, J.D. (2006) Identification of endophilins 1 and 3 as selective binding partners for VGLUT1 and their co-localization in neocortical glutamatergic synapses: implication for vesicular glutamate transporter trafficking and excitatory vesicle formation. Cell. Mol. Neurobiol. 26:677-691.

5. Erickson, J.D., De Gois, S., Varoqui, H., Schafer, M.K., and Weihe, E. (2006) Activity-dependent regulation of vesicular glutamate and GABA transporters: a means to scale quantal size. Neurochem. Int. 48:643-649.

6. De Gois, S., Schafer, M.K., Defamie, N., Chen, C., Ricci, A., Weihe, E., Varoqui, H., and Erickson, J.D. (2005) Homeostatic scaling of vesicular glutamate and GABA transporter expression in rat neocortical circuits. J. Neurosci. 25:7121-7133.

7. Wilson, N.R., Kang, J., Hueske, E.V., Leung, T., Varoqui, H., Murnick, J.G., Erickson, J.D., and Liu, G. (2005) Presynaptic regulation of quantal size by VGLUT1. J. Neurosci. 25:6221-6234.

8. Mackenzie, B., and Erickson, J.D. (2004) Sodium-coupled neutral amino acid (System N/A) transporters of the SLC38 gene family. Pflugers Arch. 447:784-795.

9. Schäfer, M.K.-H., Varoqui, H., Defamie, N., Weihe, E., and Erickson, J.D. (2002) Molecular cloning and functional identification of mouse vesicular glutamate transporter 3 and its expression in subsets of novel excitatory neurons. J. Biol. Chem. 277:50734-50748.

10. Varoqui, H., Schäfer, M.K.-H. Zhu, H., Weihe, E., and Erickson, J.D. (2002) Identification of the differentiation-associated Na+/Pi transporter as a novel vesicular glutamate transporter expressed in a distinct set of glutamatergic synapses.J. Neurosci. 22:142-155.

11. Zhu, H., Varoqui, H., Duerr, J., McManus, J.R., Rand, J., and Erickson, J.D. (2001) Analysis of unc-17 point mutants in Caenorhabditis elegans reveals domains of the vesicular acetylcholine transporter involved in substrate translocation. J. Biol. Chem. 276:41580-41587.

12. Erickson, J.D. and Varoqui, H. (2000) Molecular analysis of vesicular amine transporter function and targeting to secretory organelles. FASEB J. 14:2450-2458.

13. Varoqui, H. and Erickson J.D. (1997) Vesicular neurotransmitter transporters: potential sites for the regulation of synaptic function. Mol. Neurobiol. 15, 165-191.
Additional Info

Funding:

“Vesicular Transporter Specificity”
Principle Investigator: Jeffrey D. Erickson, PhD
Agency: NINDS/NIH (2RO1NS36936-10).
Period: 04/01/04 – 03/31/10

 “Scaling of Vesicular Glutamate and GABA Storage in Neocortical Synapses”
Principle Investigator: Jeffrey D. Erickson, PhD
Agency: NARSAD (NARSAD Southwest Florida Invesigator)
Period: 09/15/06 – 09/14/09
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