Selective @entity935 D1 and D2 agonists were used to determine the contributions of each receptor subtype in the modulation of firing rate of ventral pallidum/substantia innominata ( @entity3548 /SI) neurons. Administration of cumulative doses of the D2 agonist, @entity11640 , decreased activity in 59% of the @entity3548 /SI cells tested. The decrease in firing rate was dose-dependent between 0.002-0.2 mg/kg i.v. and was blocked by the D2 antagonist, @entity3216 (12.5 mg/kg i.v.). In addition, the magnitude and the distribution of responses of @entity3548 /SI neurons was not changed following administration of @entity11640 as a single versus a divided cumulative dose of 0.1 mg/kg. In contrast, administration of the D1 agonist, @entity2344 , excited 69% of the neurons sampled. Similar maximal responses were observed following administration of either a single or a divided cumulative dose of 3.2 mg/kg of @entity2344 . The D1 receptor antagonist, @entity10095 (0.1-0.4 mg/kg i.v.) often attenuated the @entity2344 -induced increases. The results illustrate that, (1) @entity3548 /SI neurons are sensitive to systemically administered @entity935 agonists, (2) D1 or D2 receptor activation is sufficient to change the activity of these neurons and (3) these selective agonists mediate opposite effects on @entity3548 /SI neuronal activity. These differential responses contrast with effects observed for other dopaminoceptive brain regions, and distinguish @entity3548 /SI neurons from morphologically related neurons of the dorsal globus pallidus.

XXXX D1 and D2 receptor agonists induce opposite changes in the firing rate of ventral pallidal neurons.

@entity3548 :: ('MESH:C538659', 'Disease') :: ['VP'] @entity11640 :: ('MESH:D019257', 'Chemical') :: ['quinpirole'] @entity10095 :: ('MESH:C534628', 'Chemical') :: ['SCH23390'] @entity935 :: ('MESH:D004298', 'Chemical') :: ['dopamine'] @entity3216 :: ('MESH:D013469', 'Chemical') :: ['sulpiride'] @entity2344 :: ('MESH:D015647', 'Chemical') :: ['SKF38393']
@entity935 :: (MESH:D004298,Chemical) :: ['Dopamine']
