Notes:
|
Emotional and motivational dysfunctions
observed in Parkinson’s disease, schizophrenia, and drug
addiction are associated to an alteration of the mesocortical
and mesolimbic dopaminergic pathways, which include
axons projecting to the prefrontal cortex, the ventral striatum,
and the amygdala. Subpopulations of catecholaminergic
neurons have been described in the cortex and
striatum of several mammals, but the presence of such cells
in the adult amygdala is unclear in murine rodents, and in
other rodents appears to show variations depending on the
species. Moreover, the embryonic origin of telencephalic
tyrosine hydroxylase (TH) cells is unknown, which is
essential for trying to understand aspects of their evolution,
distribution and function. Herein we investigated the
expression of TH mRNA and protein in cells of the striatum
and amygdala of developing and adult mice, and
analyzed the embryonic origin of such cells using in vitro
migration assays. Our results showed the presence of TH
mRNA and protein expressing cells in the striatum
(including nucleus accumbens), central and medial extended
amygdala during development, which are persistent in
adulthood although they are less numerous, generally show
weak mRNA expression, and some appear to lack the
protein. Fate mapping analysis showed that these cells
include at least two subpopulations with different
embryonic origin in either the commissural preoptic area of
the subpallium or the supraopto-paraventricular domain of
the alar hypothalamus. These data are important for future
studies trying to understand the role of catecholamines in
modulation of emotion, motivation, and reward.
Supported by a grant to L.M. from the Spanish Ministry of Science and Innovation, and Fondo Europeo de Desarrollo Regional (DGICYT-FEDER: grant reference BFU2009-07212/BFI), Spanish Ministry of Economy and Competitivity (grant reference BFU2012-33029). M.B. and A.V. had predoctoral fellowships from the Spanish Ministry of Education and Science. We thank Dr. Faustino Marı´n (Univ. of Murcia, Spain), who kindly sent us the cDNA for TH. |