Repeated stimulation of D1 dopamine receptors causes time-dependent alterations in the sensitivity of both D1 and D2 dopamine receptors within the rat striatum

Tolerance to the procholinergic action of the D1 receptor full agonist dihydrexidine

“…In general, repeated administration of D1 receptor agonists over a course of time appears to result in tolerance to their behavior-stimulating effects in rodents (Hu et al 1992;Asin and Wirtshafter 1993;Asin et al 1995;Engber et al 1993;Wang et al 1993;Gulwadi et al 2001), although sensitization (Silverman 1991;Subramaniam et al 1992) or absence of change (Asin et al 1997;Gulwadi et al 2001) has also been reported. Clearly, the behavioral effects of repeated D1 receptor agonist administration are influenced by several parameters, including drug doses and treatment regimen, pharmacokinetic and pharmacological properties of the administered compound, as well as the behavioral paradigm examined and the sensitivity of DA receptors at the onset of treatment.…”

Endogenous Dopamine Regulates the Rhythm of Expression of the Clock Protein PER2 in the Rat Dorsal Striatum via Daily Activation of D2Dopamine Receptors

“…To investigate whether such treatments could also restore the normal rhythm of PER2 expression in the 6-OHDA-lesioned dorsal striatum, we gave systemic injections of the D 1 DA agonist, SKF 81297 (1 mg/kg), the D 2/3 DA agonist, quinpirole (0.5 mg/kg), or vehicle (1 ml/kg) at ZT1 for 10 d, beginning 15 d after surgery. Drug doses were in the range shown previously to enhance expression of immediate-early genes, striatal peptides, and electrophysiological responses of striatal neurons in 6OHDA-lesioned rats (Gerfen et al, 1990(Gerfen et al, , 1995Hu et al, 1992;Zhang et al, 2007;Ballion et al, 2009). We chose to give the daily agonist injection at ZT1, a time at which extracellular DA levels in the striatum are normally low, to determine whether exogenous stimulation of DA receptors would not only restore PER2 expression in the lesioned striatum, but also establish a new rhythm of PER2 expression whose phase was determined by the time of the agonist injection.…”

Morphine and amphetamine sensitization in rats demonstrated under moderate- and high-dose NMDA receptor blockade with MK-801 (dizocilpine)

“…Early interest focused on targets within the mesolimbic dopamine system (Wilcox et al 1986; Robinson et al 1988;White 1991, 1995a;Hu et al 1992;Segal and Kuczenski 1992;Duffy 1993a, 1993b;. Subsequently, a number of sensitization-induced alterations have been found in the afferents and efferents of the mesolimbic dopamine system (Nestler et al 1990;Terwilliger et al 1991;Hope et al 1992;Henry and White 1995;White et al 1995a, 1995bFitzgerald et al 1996Pierce et al 1996;Carlezon et al 1997Carlezon et al , 1999Cha et al 1997;Kalivas and Duffy 1998;Churchill et al 1999).…”