The Effects of Dopamine and Serotonin on Yawning Behavior in the Rat Model of Social Isolation

A sample of 80 Male rats (21-day post weaning) were chosen, and were put for 6 weeks in separate cages with black plastic buffers. Eight rats were put in one group of 8 rats in a single cage (the control group) and the rest were put in individual cages: one male rat in each cage. In group 1 or the control group (social conditions) 8 rats were put in one cage. They received saline carrier and their yawning behavior was recorded for 60 minutes. Group 2 (n=8; in separate cages) (social isolation conditions) received no treatment with serotonin and dopamine agonist and antagonist and were kept in separate cages with one rat in each cage. Their yawning behavior was also recorded for 60 minutes. Group 3 (n=8; in separate cages) included the rats that received Apomorphine (dopamine agonist) at a dose of 0.08 mg/kg via subcutaneous injection (SC), and their yawning behavior was recorded for 60 minutes. Rats in group 4 (n=8; in separate cages) received serotonin agonist (m-CPP) at a dose of 0.5 mg/kg via subcutaneous injection, and their yawning behavior was recorded for 60 minutes. Group 5 (n=8; in separate cages) included rats that received Serotonin Antagonist (Mianserin) at a dose of 0.2 mg/kg via subcutaneous injection, and their yawning behavior was recorded for 60 minutes. Group 6 (n=8; in separate cages) included rats receiving dopamine antagonist (haloperidol) at a dose of 0.1 mg/kg via Intraperitoneal (IP) injection, and their yawning behavior was recorded for 60 minutes. Group 7 (n=8; in separate cages) included rats receiving Serotonin antagonist (Mianserin) at a dose of 0.2 mg/kg via subcutaneous injection 15 minutes before injection of apomorphine (dopamine agonist) and their yawning behavior was recorded for 60 minutes. Rats in group 8 (n=8; in separate cages) received dopamine antagonist (haloperidol) at a dose of 0.1 mg/kg via intraperitoneal injection (IP) 15 minutes before the injection of serotonin agonist (m-ccp), and their yawning behavior was recorded for 60 minutes. Rats in group 9 (n=8; in separate cages) received Apomorphine (dopamine agonist) at a dose of 0.08 mg/kg and Serotonin agonist (m-CPP) injected subcutaneously (SC) at a dose of 0.5 mg/kg and their yawning behavior was recorded for 60 minutes. Group 10 (n=8; in separate cages) included rats that received dopamine antagonists (haloperidol) at 0.1 mg/kg via intraperitoneal injection (IP) and antagonist serotonin (Mianserin) at 0.2 mg/kg injected subcutaneously and their yawning belabor was recorded for 60 minutes. Dopamine agonist (apomorphine) and serotonin antagonist (Mianserin) induce yawning in the social conditions and injection of haloperidol (dopamine antagonist) before serotonin agonist (m-ccp) reduces yawning in social conditions. Yawning is different in social conditions and social isolation conditions. Using Meta-Chlorophenylpiperazineserotonin (serotonin agonist), Mianserin (serotonin antagonist), apomorphine (dopamine agonist), haloperidol (dopamine antagonist) the role of serotonin and dopamine in yawning, fear, erection etc. can be investigated as a model for human studies.

Reversible Cerebral Vasoconstriction Syndrome in Pediatrics: A Case Series and Review

Reversible cerebral vasoconstriction syndrome is a transient vasculopathy associated with severe headaches and stroke. In most cases of reversible cerebral vasoconstriction syndrome, there is a precipitating event or trigger, such as pregnancy, serotonin agonist treatment or illicit drug use. The authors present 2 pediatric cases of reversible cerebral vasoconstriction syndrome and review the previous 11 pediatric cases in the literature. In many instances, the clinical and radiographic features are similar in both pediatric and adult cases. In the pediatric group, reported potential triggers include trauma (1/13), exercise (2/13), water to the face (3/13), hypertension (3/13), and medication or substance use (4/13). One surprising difference is that 11 out of 13 pediatric patients with reversible cerebral vasoconstriction syndrome are male while most cases in adults are female. Many of the pediatric patients with reversible cerebral vasoconstriction syndrome were treated with a calcium channel blocker and the overall outcome of pediatric reversible cerebral vasoconstriction syndrome was good, with most patients experiencing a full recovery.

The effects of acute fluoxetine administration on temporal discounting in youth with ADHD

BackgroundSerotonin is under-researched in attention deficit hyperactivity disorder (ADHD), despite accumulating evidence for its involvement in impulsiveness and the disorder. Serotonin further modulates temporal discounting (TD), which is typically abnormal in ADHD relative to healthy subjects, underpinned by reduced fronto-striato-limbic activation. This study tested whether a single acute dose of the selective serotonin reuptake inhibitor (SSRI) fluoxetine up-regulates and normalizes reduced fronto-striato-limbic neurofunctional activation in ADHD during TD.MethodTwelve boys with ADHD were scanned twice in a placebo-controlled randomized design under either fluoxetine (between 8 and 15 mg, titrated to weight) or placebo while performing an individually adjusted functional magnetic resonance imaging TD task. Twenty healthy controls were scanned once. Brain activation was compared in patients under either drug condition and compared to controls to test for normalization effects.ResultsRepeated-measures whole-brain analysis in patients revealed significant up-regulation with fluoxetine in a large cluster comprising right inferior frontal cortex, insula, premotor cortex and basal ganglia, which further correlated trend-wise with TD performance, which was impaired relative to controls under placebo, but normalized under fluoxetine. Fluoxetine further down-regulated default mode areas of posterior cingulate and precuneus. Comparisons between controls and patients under either drug condition revealed normalization with fluoxetine in right premotor-insular-parietal activation, which was reduced in patients under placebo.ConclusionsThe findings show that a serotonin agonist up-regulates activation in typical ADHD dysfunctional areas in right inferior frontal cortex, insula and striatum as well as down-regulating default mode network regions in the context of impulsivity and TD.

Mechanism of action of flibanserin, a multifunctional serotonin agonist and antagonist (MSAA), in hypoactive sexual desire disorder

Flibanserin is a novel multifunctional serotonin agonist and antagonist (MSAA) that improves sexual functioning in premenopausal women who suffer from reduced sexual interest and desire.