Joel D. Hahn

Assistant Professor Of Research in Biological Sciences
Neurobiology Section
Dornsife College of Letters, Arts and Sciences

Research Topics

  • The structural organization of brain circuits.
  • The neurobiology of aggression.
  • Additional collaborative research: 1) The neurobiology of ingestive behavior (with Dr. Scott Kanoski); 2) Mouse brain architecture (with Dr. Hongwei Dong).

Research Images

The connections of two regions of the lateral hypothalamic with the sensory, state, cognitive and motor subsystems of the nervous system, presented in the context of a basic schematic for nervous system functional organization. Numbers are the percentage by subsystem of total inputs and outputs (also represented by the diameter of the discs, and more approximately by arrow line thickness). Note that most of the connections are with the cognitive and motor subsystems, and also the bidirectional nature of connections with all subsystems. (Hahn & Swanson, Frontiers in Systems Neuroscience, 2015).

Research Overview

My field of research is systems neuroscience (the structure and function of neuronal circuits). Within this broad field, my main research interests are 1) neuronal network architecture, and 2) the structure and function of specific neuronal circuits (especially hypothalamic) involved in the control of physiological and behavioral processes that support survival and reproduction.

The image shown above (from Hahn & Swanson 2015) represents the overall connectivity of two regions of the hypothalamus with the sensory, state, cognitive, and motor subsystems of the nervous system. Underlying this summary diagram are data obtained from pathway tracing experiments. See the referenced article for further details (weblink below in Selected Publications).

Interested NGP students, please note: As a current Associate Member of the NGP Training Faculty, I am available to co-mentor students with faculty colleagues who are current full members. If this may interest you, please first approach the latter.

Contact Information

Mailing Address
Office Location HNB416B
Office Phone (213) 821-1837
Lab Location HNB426
Lab Phone
Office Location HNB416B



  • PhD in Neuroanatomy and Neuroendocrinology (King's College London, UK, 2004).

Selected Publications

  • Hahn, J.D., Sporns, O., Watts, A.G., Swanson, L.W. (2019). Macroscale intrinsic network architecture of the hypothalamus. Proc Natl Acad Sci USA. 116. (Epub ahead of print). PubMed Link
  • Hahn, J.D., Swanson, L.W. (2015) Connections of the juxtaventromedial region of the lateral hypothalamic area in the male rat. Front. Syst. Neurosci. 9(66).  PubMed Link
  • Swanson, L.W., Sporns, O., Hahn, J.D. (2015) Network architecture of the cerebral nuclei (basal ganglia) association and commissural connectome. Proc Natl Acad Sci USA 113(40):E5972-E5981.  PubMed Link
  • Rangel, M.J., Baldo, M.V.C., Canteras, N.S., Hahn, J.D. (2016) Evidence of a role for the lateral hypothalamic area juxtadorsomedial region (LHAjd) in defensive behaviors associated with social defeat. Front. Syst. Neurosci.  PubMed Link
  • Hsu, T.M., Hahn, J.D., Konanur, V.R., Lam, A., Kanoski, S.E. (2014) Hippocampal GLP-1 receptors influence food intake, meal size, and effort-based responding for food through volume transmission. Neuropsychopharmacol. 40(2):327-37. PubMed Link