Neuroscience 2005 Abstract
| Presentation Number: | 114.4 |
|---|---|
| Abstract Title: | Afferents from the A2 area of the nucleus of the solitary tract to A8 dopaminergic neurons of the retrorubral area. |
| Authors: |
Mejias-Aponte, C. A.*1
; Aston-Jones, G.1
1Dept Psychiatry, Univ. of Pennsylvania, Philadelphia, PA |
| Primary Theme and Topics |
Disorders of the Nervous System - Addiction and Drugs of Abuse -- Neurobiology of reward |
| Secondary Theme and Topics | Homeostatic and Neuroendocrine Systems<br />- Stress and the Brain<br />-- Stress-modulated pathways |
| Session: |
114. Neurobiology of Reward Poster |
| Presentation Time: | Saturday, November 12, 2005 4:00 PM-5:00 PM |
| Location: | Washington Convention Center - Hall A-C, Board # VV88 |
| Keywords: | NOREPINEPHRINE, DOPAMINE, Retrorubral , Solitary tract |
The nucleus of the solitary tract (NTS) is one of the major targets for visceral afferents to the central nervous system. Within the NTS, norepinephrine (NE) neurons of the A2 group are located within the medial and commissural subnuclei, areas that are densely innervated by the vagus nerve. We reported last year that the NE innervation of the midbrain dopamine (DA) cell areas largely originates in the A1 and A2 neurons (Mejias-Aponte et al., SfN 2004, 465.4). This was of interest as visceral (e.g., food-related) inputs to these DA cells may be involved in reward processing. Here, we extend those studies by examining ascending projections of A2 area neurons to the retrorubral area of A8 DA neurons. Immunostaining for dopamine beta-hydroxylase showed a high density of adrenergic fibers among A8 DA neurons. A less dense, but similar, pattern of fibers was also found for the epinephrine marker, phenylethanolamine N-methyl transferase, indicating that NE is the major adrenergic neurotransmitter. Retrograde labeling with the tracers cholera toxin subunit b, or wheat germ agglutinin-apo (inactivated) horseradish peroxidase conjugated to colloidal gold, confirmed that the adrenergic innervation from the NTS is primarily from NE neurons, and not from epinephrine neurons. Axonal projections from the A2 area to the retrorubral A8 area were also confirmed using the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHAL). Following injections into the A2 area, PHAL+ axons with bouton-like structures were observed in the vicinity of A8 DA neurons. Currently we are performing neurophysiology experiments to determine the effects of A2 area stimulation on A8 DA neurons. Like DA neurons of the A10 ventral tegmental area, A8 DA neurons send projections to the nucleus accumbens and the ventral pallidum, among other targets in reward circuitry. Thus, a projection from NTS A2 neurons to these cells may reveal novel circuits for visceral regulation of reward-related behaviors.
Supported by PHS grants F32DA016877 and R37DA06214
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
Copyright © 2005-2026 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
