BACKGROUND The central neuromodulator serotonin (5-HT) has been implicated in a wide range of behaviors and affective disorders, but the principles underlying its function remain elusive. One influential line of research has implicated 5-HT in response inhibition and impulse control. Another has suggested a role in affective processing. However, whether and how these effects relate to each othe...

It has been established that 5-HT(1A) receptors are expressed both presynaptically as autoreceptors by 5-HT containing neurones, and postsynaptically by a variety of other neurones. Activation of either somatodendritic 5-HT(1A) autoreceptors or postsynaptic 5-HT(1A) receptors induces hyperpolarisation and inhibition of action potential discharge of the neurones, but it is unclear whether 5-HT(1...

Serotonin's function in the brain is unclear. One challenge in testing the numerous hypotheses about serotonin's function has been observing the activity of identified serotonergic neurons in animals engaged in behavioral tasks. We recorded the activity of dorsal raphe neurons while mice experienced a task in which rewards and punishments varied across blocks of trials. We 'tagged' serotonergic...

Previous research has shown that the effect of exposure to uncontrollable stressors on conditioned fear responding and escape behavior in rats is dependent on serotonergic neural activity in the dorsal raphe nucleus (DRN). The role that norepinephrine released in the DRN plays in producing the behavioral consequences of exposure to inescapable tail shock in rats was investigated in the present ...

The inhibition of sensory responsivity is considered a core serotonin function, yet this hypothesis lacks direct support due to methodological obstacles. We adapted an optogenetic approach to induce acute, robust and specific firing of dorsal raphe serotonergic neurons. In vitro, the responsiveness of individual dorsal raphe serotonergic neurons to trains of light pulses varied with frequency a...

We previously reported that about 80% of vesicular glutamate transporter 3 (VGLUT3)-positive cells displayed immunoreactivity for serotonin, but the others were negative in the rat midbrain raphe nuclei, such as the dorsal (DR) and median raphe nuclei (MnR). In the present study, to investigate the precise distribution of VGLUT3-expressing nonserotonergic neurons in the DR and MnR, we performed...

Orexin-A and Orexin-B (also known as hypocretin 1 and 2) are, respectively, 33and 28-amino acid residue peptides that activate a G-protein-coupled ‘orphan’ receptor, i.e. which has no known ligand.1 Immuno-cytochemical studies show that orexin-positive neurons are located in the lateral hypothalamic area and arcuate and perifornical nuclei.2 They are also found in various sites beyond the hypot...

(2002) Prefrontal dopamine D1 receptors and working memory in schizophrenia. A microdialysis study of the in vivo release of 5-HT in the median raphe nucleus of the rat. Br. (1989) An in vivo dialysis and behavioural study of the release of 5-HT by p-chloroamphetamine in reserpine-treated rats. Br. In vivo brain dialysis study of the somatodendritic release of serotonin in the raphe nuclei of t...

Diabetes Mellitus (DM) is one of the most important metabolic disease causes in many side effects. The decrease of mental abilities and even some form of dementia followed prolonged diabetes has been reported. There are evidences that show hippocampus might be the site of neural involvement in patients with dementia followed diabetes. As hippocampus received main serotonergic efferents from bra...

The oxytocin receptor has been implicated in the regulation of reproductive physiology as well as social and emotional behaviors. The neurochemical mechanisms by which oxytocin receptor modulates social and emotional behavior remains elusive, in part because of a lack of sensitive and selective antibodies for cellular localization. To more precisely characterize oxytocin receptor-expressing neu...