Brainstem origins of glutamatergic innervation of the rat hypothalamic paraventricular nucleus
Version of Record online: 14 MAY 2012
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Comparative Neurology
Volume 520, Issue 11, pages 2369–2394, 1 August 2012
How to Cite
Ziegler, D. R., Edwards, M. R., Ulrich-Lai, Y. M., Herman, J. P. and Cullinan, W. E. (2012), Brainstem origins of glutamatergic innervation of the rat hypothalamic paraventricular nucleus. J. Comp. Neurol., 520: 2369–2394. doi: 10.1002/cne.23043
- Issue online: 14 MAY 2012
- Version of Record online: 14 MAY 2012
- Accepted manuscript online: 15 JAN 2012 08:48PM EST
- Manuscript Accepted: 7 JAN 2012
- Manuscript Revised: 4 SEP 2011
- Manuscript Received: 15 JUL 2011
- National Institutes of Health. Grant Numbers: MH69725, MH069860, DK078906
- HPA axis
Multiple lines of evidence document a role for glutamatergic input to the hypothalamic paraventricular nucleus (PVH) in stress-induced activation of the hypothalamic-pituitary-adrenocortical (HPA) axis. However, the neuroanatomical origins of the glutamatergic input have yet to be definitively determined. We have previously shown that vesicular glutamate transporter 2 (VGLUT2) is the predominant VGLUT isoform expressed in the basal forebrain and brainstem, including PVH-projecting regions, and that the PVH is preferentially innervated by VGLUT2-immunoreactive terminals/boutons. The present study employed a dual-labeling approach, combining immunolabeling for a retrograde tract tracer, Fluoro-Gold (FG), with in situ hybridization for VGLUT2 mRNA, to map the brainstem and caudal forebrain distribution of glutamatergic PVH-projecting neurons. The present report presents evidence for substantial dual labeling in the periaqueductal gray, caudal portions of the zona incerta and subparafascicular nucleus, and the lateral parabrachial nucleus. The current data also suggest that relatively few PVH-projecting neurons in ascending raphe nuclei, nucleus of the solitary tract, or ventrolateral medulla are VGLUT2 positive. The data reveal multiple brainstem origins of glutamatergic input to PVH that are positioned to play a role in transducing a diverse range of stressful stimuli. J. Comp. Neurol. 520:2369–2394, 2012. © 2012 Wiley Periodicals Inc.