Dopamine is a neuromodulator involved in the control of key physiological functions. Dopamine-dependent signal transduction is activated through the interaction with membrane receptors of the seven-transmembrane domain G protein-coupled family. Among them, dopamine D2 receptor is highly expressed in the striatum and the pituitary gland as well as by mesencephalic dopaminergic neurons. Lack of D...

By stimulating distinct receptor subtypes, dopamine (DA) exerts presynaptic and postsynaptic actions on both large aspiny (LA) cholinergic and fast-spiking (FS) parvalbumin-positive interneurons of the striatum. Lack of receptor- and isoform-specific pharmacological agents, however, has hampered the progress toward a detailed identification of the specific DA receptors involved in these actions...

ATTENUATION OF ANTAGONIST-INDUCED IMPAIRMENT IN DOPAMINE RECEPTOR ONTOGENY BY L-PROLYL-L-LEUCYL-GLYCINAMIDE by Mohamad Iqbal Saleh, M.D. It has been shown by others that the prenatal treatment of rats with haloperidol, a dopamine D2 receptor antagonist, leads to a permanent reduction in the number of striatal dopamine D2 receptors in adulthood. Conversely, postnatal treatment of lactating dams ...

Dopaminergic neurons are present in both plexuses of the murine bowel and are upregulated after extrinsic denervation but play unknown roles in enteric nervous system (ENS) physiology. Transcripts encoding dopamine (DA) receptors D1-D5 were analyzed by reverse transcription-PCR in stomach approximately duodenum approximately ileum approximately proximal > > distal colon. Dissected muscle and my...

The mesolimbic dopamine system and cAMP-dependent protein kinase A (PKA) pathways are strongly implicated in addictive behaviors. Here we determine the role of dopamine D2 receptors (D2) in PKA signaling responses to -opioid (DOR) and cannabinoid (CB1) receptors. We find in NG108-15 D2 cells and in cultured primary neurons that a brief exposure to saturating concentrations of DOR and CB1 agonis...

Dopamine D3 receptor pharmacology differs from that of the dopamine D2 receptor despite a high degree of receptor sequence similarity. The greatest divergence of the primary sequences of D3 and D2 receptors occurs in the predicted third intracellular loops of the receptors, a region implicated in G protein binding and function. To determine whether this domain specifies the distinct ligand bind...

The striatum receives prominent dopaminergic innervation that is integral to appetitive learning, performance, and motivation. Signaling through the dopamine D2 receptor is critical for all of these processes. For instance, drugs with high affinity for the D2 receptor potently alter timing of operant responses and modulate motivation. Recently, in an attempt to model a genetic abnormality encou...

BACKGROUND Although the principal brain target that all antipsychotic drugs attach to is the dopamine D2 receptor, traditional or typical antipsychotics, by attaching to it, induce extrapyramidal signs and symptoms (EPS). They also, by binding to the D2 receptor, elevate serum prolactin. Atypical antipsychotics given in dosages within the clinically effective range do not bring about these adve...

Background: In the recent era, smoking has become fashionable. Seventy percent of the Indian population is continuously being exposed to smoking. Cigarette smoking produces various quantities of nicotine that is readily absorbed by the physiological system of smokers. Objectives: Adolescence is the period in which smokers typically begin their nicotine addiction. To date, no attempt has been ma...

Since high-affinity adenosine A2 receptors (A2a) are localized exclusively in dopamine-rich regions in the central nervous system and mediate inhibition of locomotor activity, we have examined the effect of A2a receptor activation on D1 and D2 receptor binding in membrane preparations of the rat striatum. The A2a agonist 2-[p-(2-carboxyethyl)phenethylamino]-5'- N-ethylcarboxamidoadenosine (CGS ...