BACKGROUND Descending inhibitory pain control contributes to the endogenous defense against chronic pain and involves noradrenergic and serotonergic systems. The clinical efficacy of antidepressants suggests that serotonin may be particularly relevant for neuropathic pain conditions. Serotonergic signaling is regulated by synthesis, metabolisms, reuptake and receptors. RESULTS To address the ...

Agonistic aggression has provided an excellent framework to study how conserved circuits and neurochemical mediators control species-specific and context-dependent behavior. The principal inhibitory control upon aggression is serotonin (5-HT) dependent, and the activation of 5-HT(1A) receptors is involved in its action. To address whether the serotonergic system differentially regulates differe...

The lateral habenula (LHb) plays essential roles in behavioral responses to stressful events. Stress is tightly linked autonomic such as cardiovascular responses, yet how the LHb regulates these not well understood. To address this issue, we electrically stimulated rats, measured its effects on heart rate (HR) and mean arterial pressure (MAP), investigated neural circuits that mediate LHb-induc...

Present knowledge about the serotonergic system in birdbrains is very limited, although the pigeon was used as an animal model in various studies focused on the behavioral effects of serotonergic transmission. In the mammalian brain the 5-HT(1A) receptor is the most widespread serotonin receptor type, and is involved in various functions. Less is known about the distribution of 5-HT(1A) recepto...

Serotonin increases the level of cyclic AMP in incubated rabbit corneas; the concentration of agonist producing half-maximal stimulation is approximately 1.5 microM. Nialamide, an inhibitor of monoamine oxidase, potentiates the response to serotonin but not to epinephrine. Amitriptyline, an inhibitor of neuronal uptake of serotonin, does not potentiate the stimulation of cyclic AMP synthesis. L...

The prefrontal cortex receives a dense serotonergic innervation that plays an important role in its regulation. However, how serotonin regulates different pyramidal and interneuron cell classes in this area is incompletely understood. Previous work in rats has shown that serotonin differentially regulates two classes of pyramidal cells in layer 5. It excites one class by activating 5-HT2A recep...

BACKGROUND AND OBJECTIVES Although the mechanism of action of laser phototherapy (LPT) is not known, it is a promising analgesic method. The aim of this study was to evaluate whether the action of LPT depends on the activation of peripheral opioid or serotonergic receptors. METHOD Inflammatory pain was induced through the injection of carrageenin in the left posterior paw of male Wistar rats....

Dopamine receptors were examined by Scatchard analysis in the striatal and olfactory tubercle regions of 11 inbred mouse strains. Simultaneous determinations of the binding characteristics of 3H-labeled 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene (ADTN), a dopaminergic agonist, and [3H]spiroperidol, a dopaminergic antagonist, were examined. Among the 11 strains, the equilibrium dissocia...