The novel adenosine A2A antagonist Lu AA47070 reverses the motor and motivational effects produced by dopamine D2 receptor blockade.

Dopamine D2 and adenosine A(2A) receptors interact to regulate aspects of motor and motivational function, and it has been suggested that adenosine A(2A) antagonists could be useful for the treatment of parkinsonism and depression. The present experiments were performed to characterize the effects of Lu AA47070, which is a phosphonooxymethylene prodrug of a potent and selective adenosine A(2A) receptor antagonist, for its ability to reverse the motor and motivational effects of D2 antagonism. In the first group of studies, Lu AA47070 (3.

Oral tremor induced by galantamine in rats: a model of the parkinsonian side effects of cholinomimetics used to treat Alzheimer's disease.

Anticholinesterases are the most common treatment for Alzheimer's disease, and, in recent years, a new group of cholinesterase inhibitors (i.e. rivastigmine, galantamine, and donepezil) has become available.

Interactions between adenosine and dopamine receptor antagonists with different selectivity profiles: Effects on locomotor activity.

Forebrain dopamine (DA) is a critical component of the brain circuitry regulating behavioral activation. Adenosine A(2A) antagonists reverse many of the behavioral effects of DA antagonists, and A(2A) receptors are co-localized with D(2) receptors on striatal medium spiny neurons. The present work was undertaken to determine if the ability of an A(2A) antagonist, a non-selective adenosine antagonist, or an A(1) antagonist to reverse the locomotor effects of DA blockade in rats differed depending upon whether D(1) or D(2) family receptors were being antagonized.

Oral tremor induced by the muscarinic agonist pilocarpine is suppressed by the adenosine A2A antagonists MSX-3 and SCH58261, but not the adenosine A1 antagonist DPCPX.

Tremulous jaw movements in rats, which can be induced by dopamine (DA) antagonists, DA depletion, and cholinomimetics, have served as a useful model for studies of tremor. Although adenosine A(2A) antagonists can reduce the tremulous jaw movements induced by DA antagonists and DA depletion, there are conflicting reports about the interaction between adenosine antagonists and cholinomimetic drugs. The present studies investigated the ability of adenosine antagonists to reverse the tremorogenic effect of the muscarinic agonist pilocarpine.

Differential actions of adenosine A1 and A2A antagonists on the effort-related effects of dopamine D2 antagonism.

Adenosine and dopamine receptors in striatal areas interact to regulate a number of different functions, including aspects of motor control and motivation. Recent studies indicate that adenosine A(2A) receptor antagonists can reverse the effects of dopamine (DA) D(2) antagonists on instrumental tasks that provide measures of effort-related choice behavior. The present experiments compared the ability of the adenosine A(2A) antagonist KW6002, the nonselective adenosine antagonist caffeine, and the adenosine A(1) receptor selective antagonist DPCPX, to reverse the behavioral effects of the DA D(2) antagonist haloperidol.

The adenosine A2A antagonist MSX-3 reverses the effects of the dopamine antagonist haloperidol on effort-related decision making in a T-maze cost/benefit procedure.

Rationale: Mesolimbic dopamine (DA) is a critical component of the brain circuitry regulating behavioral activation and effort-related processes. Research involving choice tasks has shown that rats with impaired DA transmission reallocate their instrumental behavior away from food-reinforced tasks with high response requirements and instead select less effortful food-seeking behaviors.

Objective: Previous work showed that adenosine A(2A) antagonism can reverse the effects of the DA antagonist haloperidol in an operant task that assesses effort-related choice.

Telencephalic ablation results in decreased startle response in goldfish.

Our investigation concerns the connection between the telencephalon and the startle response, mediated by reticulospinal neurons. Before surgery fish respond to the startle stimulus in 95% of the trials and 66% of the time with complete full turns. Following telencephalon removal fish respond in only 50% of the trials but make complete full turns only 7% of the time.