Expression of D1 receptor mRNA in projections from the forebrain to the ventral tegmental area

Abstract

In situ hybridization was combined with Fluoro-Gold retrograde labeling to determine if cells projecting from the forebrain to the ventral tegmental area (VTA) express D1 receptor mRNA. Cell counts were made in the prefrontal cortex, shell of the nucleus accumbens, and ventral pallidum to estimate the percentage of neurons projecting to the VTA that express D1 receptor mRNA. Retrogradely labeled cells were observed in the infralimbic and prelimbic regions of the prefrontal cortex, and up to 37% of the retrogradely labeled cells expressed D1 receptor mRNA. Double-labeled cells constituted up to 89% of retrogradely labeled neurons in the rostral shell and up to 68% in the caudal shell of the nucleus accumbens. The number of retrogradely labeled cells in the ventral pallidum that were double-labeled ranged from 13% in the rostral to less than 10% in the caudal portions. These data provide anatomical support for a role of D1 receptors in the reciprocal innervation between the forebrain and VTA.

Ethanol Facilitates Glutamatergic Transmission to Dopamine Neurons in the Ventral Tegmental Area

“…In the VTA, D 1 Rs are expressed on GLUergic axons (Lu et al , 1997) but not on the soma of DA neurons (Mansour et al , 1992; Lu et al , 1997). The activation of D 1 Rs increases glutamate levels in the VTA (Kalivas and Duffy, 1995) as well as glutamatergic transmission in the globus pallidus (Hernandez et al , 2007).…”

Mechanism and Time Course of Cocaine-Induced Long-Term Potentiation in the Ventral Tegmental Area

“…The plasticity might be caused by direct activation of D 1 receptors expressed on DA neurons, but presynaptic D 1 receptors on non-DA cells (Lu et al, 1997) might contribute to the effect. Indeed, D 1 agonists microinjected into the VTA increase local release of neurotransmitters, including gluta-mate (Kalivas and Duffy, 1995).…”

Orexin/Hypocretin Modulates Response of Ventral Tegmental Dopamine Neurons to Prefrontal Activation: Diurnal Influences

“…Although anatomical studies have defined an mPFC-VTA pathway (Sesack and Pickel, 1992; Lu et al, 1997; Carr and Sesack, 2000; Geisler and Zahm, 2005; Geisler et al, 2007), physiological characterization of direct mPFC influence on DA neurons is lacking. Previously, PFC stimulation primarily produced excitations with latencies too long to be mediated by direct projections (Gariano and Groves, 1988; Tong et al, 1996).…”