the mesolimbic dopamine (da) system contains both d1-like and d2-like receptors, has been connected to control of locomotor behavior. an apparent role for d1 and d2 receptors throughout the mesolimbic system in the alteration of locomotor behavior has been demonstrated in pharmacological studies. the nucleus accumbens (nac) is comprised of a core and a shell subregion, which is a component of t...

Schizophrenia is considered to be associated with an abnormal functioning of the hippocampal output. The high clinical potency of antipsychotics that act as antagonists at dopamine (DA) receptors indicate a hyperfunction of the dopaminergic system. The subiculum obtains information from area CA1 and the entorhinal cortex and represents the major output region of the hippocampal complex. To clar...

Destruction of the substantia nigra produces striatal D1 dopamine receptor supersensitivity without increasing receptor number or affinity, thus implicating postreceptor mechanisms. The nature of these mechanisms is unknown. Increased striatal c-fos expression ipsilateral to a unilateral lesion of the substantia nigra in rats treated with appropriate dopamine agonists provides a cellular marker...

Two families of G protein-coupled receptors of the neurotransmitter dopamine, i.e., dopamine 1-like family (D1-like receptor) and dopamine 2-like family (D2-like receptor), show dopaminergic activity in nerve cells. The D2-like receptor family, composed of D2, D3, and D4 receptors, downregulates the intracellular cAMP signaling pathway, and dopamine receptor agonists reduce the cAMP level in ne...

In the present study, the effects of intra-cerebral hippocampus (CA1) injections of apomorphine D1, D2-like receptors agonists on morphine-induced place preference in male Wistar rats have been investigated. Subcutaneous administration of different dose of morphine sulphate (1, 3, 6 and 9 mg/kg) produced a dose-dependent conditioned place preference (CPP). Intra-cerebral hippocampus (CA1) admin...

Age-related dopamine (DA) losses have been extensively demonstrated for the D2 receptor subtype. Comparatively little is known about adult age changes regarding D1 receptors. In this study, we demonstrate marked age-related D1 receptor losses in striatal, limbic, and cortical areas using positron emission tomography and the radioligand [(11)C]SCH23390 in humans. Interregional correlations of bi...

The mechanisms that lead to the maintenance of chronic pain states are poorly understood, but their elucidation could lead to new insights into how pain becomes chronic and how it can potentially be reversed. We investigated the role of spinal dorsal horn neurons and descending circuitry in plasticity mediating a transition to pathological pain plasticity suggesting the presence of a chronic pa...

The neostriatum is critically involved in the control of movement. The activity of neostriatal neurons is regulated by two major inputs: a glutamatergic input from the cortex and a dopaminergic input from the substantia nigra. Ionotropic glutamate receptors mediate synaptic transmission and plasticity in the neostriatum through intrinsic ligand-gated ion channels. In contrast, dopamine receptor...

In the present study, the effects of intra-cerebral hippocampus (CA1) injections of apomorphine D1, D2-like receptors agonists on morphine-induced place preference in male Wistar rats have been investigated. Subcutaneous administration of different dose of morphine sulphate (1, 3, 6 and 9 mg/kg) produced a dose-dependent conditioned place preference (CPP). Intra-cerebral hippocampus (CA1) admin...

Overactivity in the subthalamic nucleus (STN) is believed to contribute to the pathophysiology of Parkinson's disease. It is hypothesized that dopamine receptor agonists reduce neuronal output from the STN. The present study tests this hypothesis by using in vivo extracellular single unit recording techniques to measure neuronal activity in the STN of rats with 6-hydroxydopamine-induced lesions...