Histamine is an accepted neurotransmitter and/or neuromodulator in the central nervous system (CNS). Its neuronal system in the brain is well organized, with cell bodies localized in a small area of the posterior hypothalamus. Diverse biological actions of histamine are mediated via three classes of receptors termed H1, H2, and H3. The existence of other histamine receptor subtypes is likely in...

background: high levels of histamine and dopamine are found in the hippocampus. furthermore, interaction between histamine and dopaminergic d2 receptors has been demonstrated in the modulation of some behaviors. in the present study, interaction between histamine and dopaminergic d2 receptor in the dorsal hippocampus in the anxiety behavior has been investigated. methods: in this experimental s...

Introduction: The protective and antisecretory effects of dopamine agonists on the stomach have been already reported, but the effect of bromocriptine (D2 dopamine agonist) on histamine stimulated gastric acid secretion (GAS) needs to be investigated. Methods: For gastric sampling, animals were anesthetized and a polyethylen tube was introduced into the stomach through esophagus. A cannula ...

Histamine is a well known amine which controls many physiological functions of the CNS, including; fluid balance, appetite, thermoregulation, cardiovascular control, learning and stress response. All these functions are done via three membranous H1, H2 and H3 receptors, which in laboratory animals feeding behaviour is under the control of H1 type. In order to investigate the central effect of h...

Anxiety-related behaviors increase histamine and dopamine release in the brain. On the other hand, central histamine counteracts reward and reinforcement processes mediated by the mesolimbic dopamine system. We investigated the effects of the histaminergic system and dopamine D2 receptors agents and their interactions on anxiety-related behaviors using the elevated plus-maze (EPM). The intra-hi...

introduction: the protective and antisecretory effects of dopamine agonists on the stomach have been already reported, but the effect of bromocriptine (d2 dopamine agonist) on histamine stimulated gastric acid secretion (gas) needs to be investigated. methods: for gastric sampling, animals were anesthetized and a polyethylen tube was introduced into the stomach through esophagus. a cannula was ...

Adenosine can induce hypothermia, as previously demonstrated for adenosine A1 receptor (A1AR) agonists. Here we use the potent, specific A3AR agonists MRS5698, MRS5841, and MRS5980 to show that adenosine also induces hypothermia via the A3AR. The hypothermic effect of A3AR agonists is independent of A1AR activation, as the effect was fully intact in mice lacking A1AR but abolished in mice lacki...

Adenosine can induce hypothermia, as previously demonstrated for adenosine A1 receptor (A1AR) agonists. Here we use the potent, specific A3AR agonists MRS5698, MRS5841, and MRS5980 to show that adenosine also induces hypothermia via theA3AR. The hypothermic effect of A3ARagonists is independent of A1AR activation, as the effect was fully intact in mice lacking A1AR but abolished in mice lacking...

The superior vestibular nucleus (SVN), which holds a key position in vestibulo-ocular reflexes and nystagmus, receives direct hypothalamic histaminergic innervations. By using rat brainstem slice preparations and extracellular unitary recordings, we investigated the effect of histamine on SVN neurons and the underlying receptor mechanisms. Bath application of histamine evoked an excitatory resp...

the present study investigated the effects of intra-dentate gyrus microinjection of naloxone (an opioid antagonist) and thioperamide (an antagonist of histamine h3 receptors) in the formalin test in rats. subcutaneous injection of formalin (50 μl, 2.5 %) in the ventral surface of right hind paw produced a biphasic pattern (first phase: 0-5 min and second phase: 15 - 60 min) of licking/biting an...