Given an abstract from a research paper, your task is to identify and label relationships between chemical compounds and genes mentioned in the abstract.

The relationship type must be one of ['DOWNREGULATOR', 'SUBSTRATE', 'INDIRECT-REGULATOR', 'PART-OF', 'MODULATOR-ACTIVATOR', 'REGULATOR', 'INHIBITOR', 'COFACTOR', 'UPREGULATOR', 'ACTIVATOR', 'ANTAGONIST', 'NOT', 'INDIRECT-DOWNREGULATOR', 'SUBSTRATE_PRODUCT-OF', 'INDIRECT-UPREGULATOR', 'AGONIST', 'PRODUCT-OF', 'MODULATOR', 'DIRECT-REGULATOR', 'UNDEFINED', 'AGONIST-INHIBITOR', 'AGONIST-ACTIVATOR', 'MODULATOR-INHIBITOR'].

Please format your output as a JSON array. Each entry in the array should express a single relation, formatted as ["<Entity_A>", "<RELATION_A_B>", "<Entity_B>"]. If no relations can be found, please output an empty JSON array [].

Abstract:

Dopamine D2/3 receptor binding potential and occupancy in midbrain and temporal cortex by haloperidol, olanzapine and clozapine. AIMS: Aberrant dopamine transmission in extrastriatal brain regions has been repeatedly illustrated among patients with schizophrenia. Differences between typical and second-generation antipsychotics in dopamine D (2) receptor modulation within various brain areas remain a topic for debate. The aim of the present study was therefore to investigate dopamine D (2/3) receptor apparent binding potential (BP (app)) and occupancy in midbrain and temporal cortex among clozapine-, olanzapine- and haloperidol-treated schizophrenia patients. METHODS: Dopamine D (2/3) binding was studied on single-photon emission computed tomography ligand [ (123) I]epidepride in 13 schizophrenia patients treated with medication (two with haloperidol, four with olanzapine and seven with clozapine), six drug-naive patients and seven healthy controls. RESULTS: Statistically significant differences in midbrain dopamine D (2/3) receptor BP (app) (P = 0.015) and occupancy (P = 0.016) were observed between the clozapine, olanzapine and haloperidol groups. The lowest occupancy was found in clozapine-treated patients (5%), followed by olanzapine-treated patients (28%), compared to haloperidol-treated patients (40%). No significant differences were observed in the temporal poles. Occupancy changed substantially depending on the comparison group used (either drug-naive vs healthy controls) in the examined brain areas (P = 0.001), showing an overestimation with all antipsychotics when the healthy control group was used. CONCLUSION: Both typical and second-generation antipsychotics occupy cortical dopamine D (2/3) receptors, thus mediating therapeutic efficacy. Observed differences in midbrain dopamine D (2/3) occupancy between classical antipsychotics and second-generation antipsychotics may have clinical relevance by modulating altered nigrostriatal dopamine neurotransmission during the acute phase of schizophrenia.
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