Nucleus Parabrachialis Pigmentosus

The second dot of pigmentation after Substantia Nigra is Nucleus Brachialis Pigmentosis.

Google Scholar contains several articles concerning this region of the amenta nerve tract dating back to 1992, over thirty years ago.

"Oligonucleotides and a full-length cDNA encoding a functional dopamine transporter (DAT1) hybridize to a 3.7 kb mRNA that is concentrated in mRNA prepared from midbrain and absent in specimens from cerebellum or cerebral cortex. In situ hybridization reveals substantial hybridization densities overlying neurons of the substantia nigra, pars compacta, and the [nucleus] parabrachialis pigmentosus region of the ventral tegmental area (VTA). Neurons in the linear and paranigral VTA regions display lower levels of expression."1 Keep in mind that hybridization refers to cross-polinating.

Another white paper publish in 1992, in Neuroscience states, "A dopaminergic projection from the ventral tegmental area to the ventral pallidum was identified in the rat using anterograde tract tracing and combined retrograde tracing-immunocytochemistry. The projection was found to be topographically organized such that fibers innervating the ventromedial ventral pallidum arose from neurons located along the midline nuclei of the ventral mesencephalon, including the nucleus interfascicularis and nucleus linearis caudalis. Ventral tegmental neurons situated more laterally, in the nucleus parabrachialis pigmentosus and nucleus paranigralis, projected to the ventromedial and dorsolateral ventral pallidum."*2

References

1. Dopamine transporter mRNA: dense expression in ventral midbrain neurons Shoichi Shimada; Shigeo Kitayama; Donna Walther; GeorgeUhl Laboratory of Molecular Neurobiology, Addiction Research Center, NIDA and Departments of Neurology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21224 USA
2. Topography and Functional Role of Dopaminergic Reactions from the Ventral Mesencephalic Tegmentum to the Ventral Pallidum, M.A. Klitenick, A.Y. Deutch; ["L. Churchill and P.W. Kalivas] Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Washington State University, Pullman, WA 99164-6520, U.S.A. Departments of Psychiatry and Pharmacology, Yale University School of Medicine, New Haven, Connecticut, U.S.A

euroscience Vol. 50, No. 2, pp. 371 386, 1992
Printed in Great Britain
0306-4522/92 $5.00+ 0.00
Pergamon Press Ltd
IBRO
T O P O G R A P H Y A N D F U N C T I O N A L ROLE OF
D O P A M I N E R G I C PROJECTIONS F R O M THE V E N T R A L
M E S E N C E P H A L I C T E G M E N T U M TO THE V E N T R A L
P A L L I D U M
M. A. KLITENICK,*A. Y. DEUTCH,'["L. CHURCHILL and P. W. KALIVAS
Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology,
Washington State University, Pullman, WA 99164-6520, U.S.A.
tDepartments of Psychiatry and Pharmacology, Yale University School of Medicine,
New Haven, Connecticut, U.S.A.
Abstract--A dopaminergic projection from the ventral tegmental area to the ventral pallidum was
identified in the rat using anterograde tract tracing and combined retrograde tracing-
immunocytochemistry. The projection was found to be topographically organized such that fibers
innervating the ventromedial ventral pallidum arose from neurons located along the midline nuclei of the
ventral mesencephalon, including the nucleus interfascicularis and nucleus linearis caudalis. Ventral
tegmental neurons situated more laterally, in the nucleus parabrachialis pigmentosus and nucleus
paranigralis, projected to the ventromedial and dorsolateral ventral pallidum. The substantia nigra did
not supply a major contribution to this projection. The proportion of ventral tegmental area dopaminergic
neurons projecting to the ventral pallidum ranged from approximately 30% to 60%. The functional
significance of the projection is indicated since intra-ventral pallidum microinjections of dopamine elicited
a dose-dependent increase in locomotor activity. Furthermore, whereas pretreatment of the ventral
pallidum with the GABAA agonist muscimol has been shown to attenuate opioid-induced locomotor
activity elicited from the ventral pallidum, it did not attenuate the dopamine-induced motor response.