Medullary Norepinephrine Projections Release Norepinephrine into the Contralateral Bed Nucleus of the Stria Terminalis.
Central norepinephrine signaling influences a wide range of behavioral and physiological processes, and the ventral bed nucleus of the stria terminalis (vBNST) receives some of the densest norepinephrine innervation in the brain. Previous work describes norepinephrine neurons as projecting primarily unilaterally; however, recent evidence for cross-hemispheric catecholamine signaling challenges this idea. Here, we use fast-scan cyclic voltammetry and retrograde tracing to characterize cross-hemispheric norepinephrine signaling in the vBNST. We delivered stimulations to noradrenergic pathways originating in the A1/A2 and locus coeruleus and found hemispherically equivalent norepinephrine release in the vBNST regardless of stimulated hemisphere. Unilateral retrograde tracing revealed that medullary, but not locus coeruleus norepinephrine neurons send cross-hemispheric projections to the vBNST. Further characterization with pharmacological lesions revealed that stimulations of the locus coeruleus and its axon bundles likely elicit vBNST norepinephrine release through indirect activation. These experiments are the first to demonstrate contralateral norepinephrine release and establish that medullary, but not coerulean neurons are responsible for norepinephrine release in the vBNST.
Department of Chemistry, Neuroscience Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Megan E
ME
Fox
Department of Chemistry, Neuroscience Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Elizabeth S
ES
Bucher
Department of Chemistry, Neuroscience Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Justin A
JA
Johnson
Department of Chemistry, Neuroscience Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
R Mark
RM
Wightman
D000818:Animals; D004558:Electric Stimulation; D007839:Functional Laterality / Q000502:physiology; D007051:Ibotenic Acid; D008125:Locus Coeruleus / Q000166:cytology / Q000293:injuries / Q000378:metabolism; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology / Q000378:metabolism*; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism; D056347:Neuroanatomical Tract-Tracing Techniques; D056325:Neuronal Tract-Tracers; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D016627:Oxidopamine; D017207:Rats, Sprague-Dawley; D012686:Septal Nuclei / Q000166:cytology / Q000378:metabolism*; D013266:Stilbamidines
C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D056325:Neuronal Tract-Tracers; D013266:Stilbamidines; D007051:Ibotenic Acid; D016627:Oxidopamine; D009638:Norepinephrine
Norepinephrine; cross-hemispheric; fast-scan cyclic voltammetry; locus coeruleus; nucleus of the solitary tract; ventral bed nucleus of the stria terminalis