Previous studies in the auditory cortex of Mongolian gerbils on discrimination learning of the direction of frequency-modulated tones (FMs) revealed that long-term memory formation involves activation of the dopaminergic system, activity of the protein kinase mammalian target of rapamycin (mTOR), and protein synthesis. This led to the hypothesis that the dopaminergic system might modulate memor...

Brain cannabinoid CB(1) receptors are expressed in neural areas that contribute to movement such as basal ganglia, where they co-localize with dopamine D(1) and D(2) receptors. The objective of the present study was to further study the functional role of CB(1) receptors along with D(1) and D(2) dopamine receptors of basal ganglia by local injections of SR141716A (CB(1) receptor antagonist), SK...

The role of dopamine in regulating spinal cord function is receiving increasing attention, but its actions on spinal motor networks responsible for rhythmic behaviors remain poorly understood. Here, we have explored the modulatory influence of dopamine on locomotory central pattern generator (CPG) circuitry in the spinal cord of premetamorphic Xenopus laevis tadpoles. Bath application of exogen...

Polymorphisms in the gene coding for the adhesion G-protein coupled receptor LPHN3 are a risk factor for attention-deficit/hyperactivity disorder (ADHD). Transient down-regulation of latrophilin3.1 (lphn3.1), the zebrafish LPHN3 homologue, causes hyperactivity. Zebrafish injected with a lphn3.1-specific morpholino are hyperactive and display an impairment in dopaminergic neuron development. In ...

A neuropsychological hallmark of attention deficit/hyperactivity disorder (ADHD) is the reduced ability to tolerate delay of reinforcement, leading to impulsive choice. Genetic association studies have implicated several genes involved in dopaminergic neurotransmission in ADHD. In this study, we investigated whether differences in the expression level of these dopamine-related genes of rats pre...

Object recognition memory is the ability to identify previously seen objects and is an adaptive mechanism that increases survival for many species throughout the animal kingdom. Previously believed to be possessed by only the highest order mammals, it is now becoming clear that fish are also capable of this type of memory formation. Similar to the mammalian hippocampus, the dorsolateral pallium...

Impairment of renal dopamine D1 receptor (D1R)-mediated natriuresis is associated with hypertension in humans and animal models, including obese Zucker rats. We have previously reported that treatment of these rats with antioxidants or insulin sensitizers reduced insulin levels and oxidative stress, restored D1R-mediated natriuresis, and reduced blood pressure. Furthermore, the redox-sensitive ...

PURPOSE The electrophysiologic study using patch-clamp techniques demonstrated that NMDA-induced currents had properties similar to those recorded in the brain. METHODS Primary cultures obtained from the fetal rat retina (gestation days 16 to 19) were used for the experiment. Immunocytochemical and electrophysiologic studies were done to identify the cultured cells. The neurotoxic effects of ...

In the present study, we investigated the existence of a back-regulation of the catecholamine-degrading enzyme monoamine oxidase (MAO)-A by dopamine in rat renal cells. In proximal tubule cells, MAO-A expression was not modified after dopamine receptor stimulation. In contrast, in mesangial cells, enzyme assay and Western blots showed that MAO activity and protein increased by approximately 80%...

Activation of 5-HT(2A) receptors is thought to mediate the hallucinogenic effects of LSD. Nevertheless, in a previous report we provided evidence that a delayed temporal phase of the behavioral pharmacology of LSD is mediated by D(2)-like dopamine receptor stimulation. In this study rats were trained to discriminate LSD with either a 30 min preinjection time (LSD-30, N=12) or a 90 min preinject...