Background Ketamine rapidly elicits antidepressive effects in humans and mice in which serotonergic activity is involved. Although α4β2 nicotinic acetylcholine receptor (α4β2 nAChR) in the dorsal raphe nucleus plays a key role in the ketamine-induced prefrontal serotonin release, the source of cholinergic afferents, and its role is unclear. Methods Prefrontal serotonin levels after ketamine i...

To investigate the release profile of met-enkephalin, β-endorphin, and dynorphin-A in ruminants' CNS, goats were stimulated by electroacupuncture of 0, 2, 40, 60, 80, or 100 Hz for 30 min. The pain threshold was measured using potassium iontophoresis. The peptide levels were determined with SABC immunohistochemisty. The results showed that 60 Hz increased pain threshold by 91%; its increasing r...

(Neuron 106, 498–514.e1–e8, May 6, 2020) In the original version of this paper, representative heatmap in lower panel Figure 5B was incorrectly presented as duplicate upper panel. The online figure has been updated with correct data. This mistake does not affect any other data and analysis paper. There is no associated change to text. authors apologize for error. Raphe Dopamine System Controls ...

Recent neuroanatomical and behavioral evidence has indicated that vasopressin (VA) increases pain threshold. The dorsal raphe nucleus (DRN) is an important nucleus in pain modulation. Anatomical studies have shown that DRN receives vasopressinergic fibers originating in the hypothalamic paraventricular nucleus. The aim of the present study was to examine the effects of intra-DRN injection of de...

The ascending serotonergic projections are derived mainly from mesencephalic raphe nuclei. Topographical projections from mesencephalic raphe nuclei to the striatum were examined in the rat by the retrograde transport technique of HRP (horseradish peroxidase). In 29 rats stereotaxically injection of HRP enzyme were performed in dorsal and ventral parts of striatum separately. The extent of the ...

Extracellular electrophysiological recordings in freely moving cats have shown that serotonergic neurons from the dorsal raphe nucleus (DRN) fire tonically during wakefulness, decrease their activity during slow wave sleep (SWS), and are nearly quiescent during paradoxical sleep (PS). The mechanisms at the origin of the modulation of activity of these neurons are still unknown. Here, we show in...

There is a dense serotonergic projection from nucleus raphe pallidus and nucleus raphe obscurus to the trigeminal motors nucleus and serotonin exerts a strong facilitatory action on the trigeminal motoneurons. Some serotonergic neurons in these caudal raphe nuclei increase their discharged during feeding. The objective of the present study was to investigate the possibility that the activity of...

Whether increased serotonin (5-HT) release in the forebrain attenuates or enhances anxiety has been controversial for over 25 yr. Although there is considerable indirect evidence, there is no direct evidence that indicates a relationship between acute 5-HT release and anxiety. In particular, there is no known method that can reversibly, selectively, and temporally control serotonergic activity....

The aim of this study was to track the immunoreactivity of parvalbumin and calbindin D28k buffering proteins in neurons of the dorsal raphe nucleus DRN of the adult male chinchilla. The reaction of peroxidase-antiperoxidase (PAP) using specific antibodies against these proteins was performed. In most neurons, with the exception of small oval and medium-sized, stellate neurons, weak immunostaini...

The nucleus paragigantocellularis (PGI) is located in the rostral ventrolateral medulla and has noticeable connections with some other brain nuclei, such as locus ceruleus, nucleus raphe magnus and periaqueductal gray. In rats it is 3 mm in rostrocaudal and 1 mm in mediolateral and 1 mm in the dorsolateral aspect. Anatomically and functionally, PGI has been divided into two subnuclei, retrofaci...