PT  - JOURNAL ARTICLE
AU  - Carlos A. Mejías-Aponte
AU  - Candice Drouin
AU  - Gary Aston-Jones
TI  - Adrenergic and Noradrenergic Innervation of the Midbrain Ventral Tegmental Area and Retrorubral Field: Prominent Inputs from Medullary Homeostatic Centers
AID  - 10.1523/JNEUROSCI.4632-08.2009
DP  - 2009 Mar 18
TA  - The Journal of Neuroscience
PG  - 3613--3626
VI  - 29
IP  - 11
4099  - http://www.jneurosci.org/content/29/11/3613.short
4100  - http://www.jneurosci.org/content/29/11/3613.full
SO  - J. Neurosci.2009 Mar 18; 29
AB  - Adrenergic agents modulate the activity of midbrain ventral tegmental area (VTA) neurons. However, the sources of noradrenergic and adrenergic inputs are not well characterized. Immunostaining for dopamine β-hydroxylase revealed fibers within dopamine (DA) neuron areas, with the highest density in the retrorubral field (A8 cell group), followed by the VTA (A10 cell group), and very few fibers within substantia nigra compacta. A less dense, but a similar pattern of fibers was also found for the epinephrine marker, phenylethanolamine N-methyl transferase. Injection of the retrograde tracer wheat germ agglutinin-apo (inactivated) horseradish peroxidase conjugated to colloidal gold, or cholera toxin subunit b, revealed that the noradrenergic innervation of the A10 and A8 regions arise primarily from A1, A2, A5, and locus ceruleus neurons. Selective lesions of the ventral noradrenergic bundle confirmed a prominent innervation from A1 and A2 areas. Retrogradely labeled epinephrine neurons were found mainly in the C1 area. The identification of medullary noradrenergic and adrenergic afferents to DA neuron areas indicates new pathways for visceral-related inputs to reward-related areas in the midbrain.