High-resolution Scatchard analysis shows D1 receptor binding on pyramidal and nonpyramidal neurons

Abstract

In order to better understand the mechanism of action of atypical antipsychotic drugs (APDs), it is important to clarify how the dopamine system is integrated within local corticolimbic circuits. Toward this end, a high-resolution (HR) Scatchard technique has been used to measure the relative density (Bmax) and affinity (Kd) of D1 receptors on large neurons (> 100 microm2), on small neurons (< 100 microm2), and in neuropil (NPL) of rat medial prefrontal cortex (mPFC) and to determine the laminar distribution of these receptors for each neuronal compartment. Using [3H] SCH23390 as a ligand, all Kd and Bmax values were found to be similar indicating that D1 receptor activity is not preferentially localized to either large or small neuronal subtypes in mPFC. The density of D1 receptor binding in all three compartments was found to be almost twice as great in layers V and VI, as compared to superficial layers II and III. These results suggest that the blockade of D1 receptors associated with some atypical APDs may involve both pyramidal and nonpyramidal neurons in the PFC.

Mesocorticolimbic Dopamine Pathways Across Adolescence: Diversity in Development

“…Both pyramidal and GABAergic interneurons in the PFC express DA receptors of the D1 (D1 and D5) and D2 (D2, D3, D4) families (Gaspar et al, 1995 ; Vincent et al, 1995 ; Knable and Weinberger, 1997 ; Lu et al, 1997 ; Davidoff and Benes, 1998 ; Le Moine and Gaspar, 1998 ; Mitrano et al, 2014 ). DA receptors are seven transmembrane G-protein coupled receptors that initiate intracellular cascades by increasing cAMP (D1-type) or decreasing cAMP (D2-type; Seamans and Yang, 2004 ; Tritsch and Sabatini, 2012 ).…”

Transient D1Dopamine Receptor Expression on Prefrontal Cortex Projection Neurons: Relationship to Enhanced Motivational Salience of Drug Cues in Adolescence

“…In contrast, postadolescent D 1 expression appeared largely on GABAergic interneurons, which has been previously found in fluorescent ligand binding studies (Vincent et al, 1995). Davidoff and Benes (1998) suggest, rather, that D 1 is evenly distributed on pyramidal and nonpyramidal cells in the adult rat PFC. The current adult data suggests that more interneurons than NActerminating neurons express D 1 .…”