BACKGROUND AND PURPOSE Dopamine released from the endings of descending dopaminergic nerve fibres in the spinal cord may be involved in modulating functions such as locomotion and nociception. Here, we examined the effects of dopamine on spinal synaptic transmissions in rats. EXPERIMENTAL APPROACH Spinal reflex potentials, monosynaptic reflex potential (MSR) and slow ventral root potential (s...

Abstract Although the rates of response to first-line pharmacological treatments (serotonin reuptake inhibitors – SRIs) are generally twice that placebo, only 40-60% patients respond sufficiently or able tolerate traditional pharmacotherapy. Augmentation with dopamine antagonist medications is associated strongest evidence, yet antagonists benefit a minority those who try them and carry elevate...

The non-catechol, selective dopamine D2-agonist compound 3H-205-502 was used to localize dopamine D2 receptors by autoradiography after in vitro labeling of brain sections. The characteristics of the binding of this ligand to tissue sections were those expected from the labeling of dopamine D2 receptors. The binding of 3H-205-502 was inhibited selectively and stereospecifically by dopamine D2 a...

More than half a century ago, Delay and colleagues have discovered, quite accidentally, that antihistamine (chlorpromazine) relieves psychotic symptoms. This discovery prompted further investigation through a series of performed experiments aimed to elucidate the antipsychotic mechanism of action. Initial results have shown that antipsychotic drugs in experimental animals lead to "neuroleptic e...

Our current understanding of the relationship between the dopaminergic system and human brain disorders is based on two fundamental discoveries: dopamine-replacement herapy can alleviate Parkinson’s disease (1-3) and, secondly, many antipsychotic drugs are dopamine receptor antagonists (4-7). These discoveries have guided two major directions in dopamine-related basic research and drug design: ...

The possible interaction of melatonin receptors and D1 dopamine receptors was investigated in neural cells prepared from embryonic day 8 chick retinas and cultured for 6 d. Dopamine stimulated cAMP accumulation in cultured retinal cells. This effect of dopamine was antagonized by addition of dopamine receptor antagonists (haloperidol and SCH23390) or melatonin receptor agonists (melatonin, 2-io...

The reinforcing properties of cocaine have been related to increased extracellular concentrations of dopamine in the nucleus accumbens (NAc). M5 muscarinic acetylcholine receptors (mAChRs) on dopamine cells in the ventral tegmental area (VTA) facilitate mesoaccumbens dopamine transmission and are critically involved in mediating natural and drug reinforcement. We investigated the effects of pha...

ATTENUATION OF ANTAGONIST-INDUCED IMPAIRMENT IN DOPAMINE RECEPTOR ONTOGENY BY L-PROLYL-L-LEUCYL-GLYCINAMIDE by Mohamad Iqbal Saleh, M.D. It has been shown by others that the prenatal treatment of rats with haloperidol, a dopamine D2 receptor antagonist, leads to a permanent reduction in the number of striatal dopamine D2 receptors in adulthood. Conversely, postnatal treatment of lactating dams ...

Cortical neurons respond in a variety of ways to locally applied dopamine, perhaps because of the activation of different receptors within or among subpopulations of cells. This study was conducted to assess the effects of dopamine and the receptor subtypes that mediate the responses of a specific population of neurons, the pyramidal tract neurons (PTNs) in the rodent motor cortex. The specific...

In neurodegenerative disorders associated with primary or secondary mitochondrial defects such as Huntington's disease (HD), cells of the striatum are particularly vulnerable to cell death, although the mechanisms by which this cell death is induced are unclear. Dopamine, found in high concentrations in the striatum, may play a role in striatal cell death. We show that in primary striatal cultu...