Orexin/hypocretin neurons in the lateral hypothalamus and adjacent perifornical area (LH/PFA) innervate midbrain dopamine (DA) neurons that project to corticolimbic sites and subserve psychostimulant-induced locomotor activity. However, it is not known whether dopamine neurons in turn regulate the activity of orexin cells. We examined the ability of dopamine agonists to activate orexin neurons ...

The possible interaction between cholinergic and dopaminergic influences in the induction of yawning behavior in the rat is explored resorting to several experimental approaches: comparison of the ontogeny of yawning behavior induced by physostigmine (0.15 mg/kg) and apomorphine (0.05 mg/kg); simultaneous injection of both drugs; "crossed blocking" experiments, in which the action of the cholin...

Repeated psychostimulants induce electroencephalographic (EEG) changes, which reflect adaptation of the neural substrate related to dopaminergic pathways. To study the role of dopamine receptors in EEG changes, we examined the effect of apomorphine, the dopamine D1 receptor antagonist, SCH-23390, and the D2 receptor antagonist, haloperidol, on EEG in rats. For single and repeated apomorphine tr...

B dopaminergic receptor activation, either by levodopa or by direct dopamine receptor agonists, remains the bulwark of treatment of Parkinson’s disease.1 Levodopa and direct dopamine agonists are often used concurrently. Although it is known that apomorphine does not affect the pharmacokinetics of orally administered levodopa,2 it is not known whether dopamine agonists alter plasma levels of la...

Apomorphine has been used as a pharmacological probe of dopaminergic receptors in a variety of central nervous system disorders. The utility of apomorphine as an agent for the treatment of erectile dysfunction has also been demonstrated clinically. Apomorphine is a nonselective dopaminergic receptor agonist with potent binding affinity (Ki) of 101, 32, 26, 2.6, and 10 nM for D1, D2, D3, D4, and...

Apomorphine is a dopamine receptor agonist proposed to be a neuroprotective agent in the treatment of patients with Parkinson's disease. Both in vivo and in vitro studies have shown that apomorphine displays both antioxidant and pro-oxidant actions, and might have either neuroprotective or neurotoxic effects on the central nervous system. Some of the neurotoxic effects of apomorphine are mediat...

objective(s): the dopamine level of the nucleus accumbens changes during some stereotyped behaviors. to study dopamine level of the nucleus accumbens in intra infralimbic apomorphine-induced climbing, microdialysis probes were implanted into the nucleus accumbens shell of male sprague dawley rats weighting 275–400 g.   materials and methods: the rats were divided into two groups (apomorphine an...

Sensitization is a common feature of psychostimulants and sensitization effects are generally considered to be linked to the addictive properties of these drugs. We used a conventional paired/unpaired Pavlovian protocol to induce a context specific sensitization to the locomotor stimulant effect of a high dose of apomorphine (2.0mg/kg). Two days following a 5 session sensitization induction pha...

OBJECTIVE(S) The dopamine level of the nucleus accumbens changes during some stereotyped behaviors. To study dopamine level of the nucleus accumbens in intra infralimbic apomorphine-induced climbing, microdialysis probes were implanted into the nucleus accumbens shell of male Sprague Dawley rats weighting 275-400 g. MATERIALS AND METHODS The rats were divided into two groups (apomorphine and ...

Background: Fluctuation-related pain (worse in OFF periods) is a frequent and disabling symptom Parkinson’s disease (PD). As evidence-based treatments to treat PD are limited, exploring alternatives it imperative. Apomorphine the only antiparkinsonian agent compatible with levodopa improving motor symptoms usually well tolerated. We explored effects of apomorphine fluctuation-related pain. Meth...