Locomotor responses caused by dopamine receptor agonists with presumed specificity for D-1 or D-2 subtypes were compared to apomorphine-induced locomotion in neonatally and adult 6-hydroxydopamine (6-OHDA)-treated rats. In 6-OHDA-treated rats, apomorphine the agonist, LY-171555, produced a marked, dose-related increase locomotor activity. Increases observed rats after LY-171555 administration less than one-third of those seen treated as adults 6-OHDA. Neonatally positive...

Abstract: The present investigation examined the effects of neonatal and adult 6‐hydroxydopamine (6‐OHDA)‐induced lesions dopaminergic neurons on opioid tachykinin peptides their gene expression in rat basal ganglia. This work was undertaken to determine if changes these neuropeptide systems were contributing differing behavioral responses observed between neonatally adult‐lesioned rats after dopamine agonist administration. [Met 5 ]Enkephalin (ME) content increased striatal tissue from both...

The ventral pallidum/substantia innominata (VP/SI) is an infracommissural extension of the dorsal globus pallidus (GP). Functional studies suggest that VP/SI indirectly influenced by dopamine (DA) via inputs from dopaminoceptive regions. However, recent anatomical evidence indicates a direct dopaminergic projection to VP/SI, but physiologic and pharmacologic consequences this input have not been evaluated. Thus, present study was designed electrophysiologically characterize neuronal...

Dysregulated dopamine transmission in striatal circuitry is associated with impulsivity. The current study evaluated the influence of dopaminergic inputs to dorsolateral striatum on impulsive choice, one aspect behavior. We implemented an operant task that measures choice rats via delay discounting wherein intracranial self-stimulation (ICSS) was used as positive reinforcer. To do so, were anesthetized allow implanting a stimulating electrode within lateral hypothalamus hemisphere and...

Abstract Methamphetamine (Meth) abuse may be a risk factor for Parkinson's disease ( PD ); problematic event as approximately 33 million people Meth worldwide. The current study determined if mild form of ‐like nigrostriatal pathology occurred following forced abstinence in self‐administering rats. average daily intake self‐administered was 3.6 ± 0.2 mg/kg/3 h over 14 sessions. Subsequently, animals were killed and the brains harvested at 1, 7, 28 or 56 days abstinence. Post mortem ,...

Enhancements in behavior that accompany repeated, intermittent administration of abused drugs (sensitization) endure long after drug has ceased. Such persistence reflects changes intracellular signaling cascades and associated gene transcription factors brain regions are engaged by drugs. This process is not characterized for the most potent psychomotor stimulant, methamphetamine. Using motor as an index state rats, we verified five once-daily injections 2.5 mg/kg methamphetamine induced...

The environmental context in which abused drugs are taken contribute to the drug experience and is a powerful persistent stimulus elicit memories of that even abstinent addict. Using amphetamine (AMPH) as unconditioned stimulus, present study compared two popular context-dependent paradigms rats, conditioned motor sensitization (CMS) place preference (CPP), ascertain whether particular brain regions were differentially involved. neuronal substrates underlying these behaviors poorly...

Abstract The ventral pallidum is a basal forebrain region recently shown to receive dopaminergic projections from the midbrain. Binding sites for D1 and D2 dopamine receptor families have been identified within pallidum, yet consequences of activating these receptors not studied. Thus, characterize physiological pharmacology subtypes extracellular single‐neuron recording microiontophoretic techniques were used in chloral hydrate‐anesthetized rats. Half 93 pallidal neurons tested sensitive...