There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
In female rats the gonadal hormones estrogen and progesterone modulate dopamine (DA)
activity in the striatum and nucleus accumbens. For example, there is estrous cycle-dependent
variation in basal extracellular concentration of striatal DA, in amphetamine (AMPH)-stimulated
DA release, and in striatal DA-mediated behaviors. Ovariectomy attenuates basal extracellular
DA, AMPH-induced striatal DA release, and behaviors mediated by the striatal DA system.
Estrogen rapidly and directly acts on the striatum and accumbens, via a G-protein-coupled
external membrane receptor, to enhance DA release and DA-mediated behaviors. In male
rats, estrogen does not affect striatal DA release, and removal of testicular hormones
is without effect. These effects of estrogen also result in gender differences in
sensitization to psychomotor stimulants. The effects of the gonadal hormones on the
striatum and ascending DA systems projecting to the striatum and nucleus accumbens
are hypothesized to occur as follows: estrogen induces a rapid change in neuronal
excitability by acting on membrane receptors located in intrinsic striatal GABAergic
neurons and on DA terminals. The effect of these two actions results in enhanced stimulated
DA release through modulation of terminal excitability. These effects of gonadal hormones
are postulated to have important implications for gender differences in susceptibility
to addiction to the psychomotor stimulants. It is suggested that hormonal modulation
of the striatum may have evolved to facilitate reproductive success in female rats
by enhancing pacing behavior.