Serotonergic mechanisms in the 6-Hz psychomotor seizures in mice

Abstract

<jats:p> Serotonin (5-hydroxytrytamine (5-HT)) plays an important role in experimental seizures. Recently, we reported the depletion of 5-HT by parachlorophynylalanine (PCPA) in whole brain to enhance 6-Hz psychomotor seizures in mice. In the present work, we investigated the effect of 5-HT depletion in cortex and hippocampus, brain regions relevant for epilepsy, on behavioral and ultra-structural changes following 6-Hz psychomotor seizures in mice. In addition, we studied the effect of sodium valproate (SVP) on behavioral, biochemical, and ultra-structural effects induced by 6 Hz. Behavioral changes induced by 6 Hz stimulation were characterized as the increased duration of Straub’s tail, stun position, twitching of vibrissae, forelimb clonus, and increased rearing and grooming. PCPA administration further enhanced while SVP reduced these behaviors in mice. The 6-Hz psychomotor seizure induced ultra-structural changes in both cortex and hippocampus in mice treated with PCPA. Furthermore, PCPA administrations followed by 6Hz-induced seizures were accompanied by reduced hippocampal and cortical 5-HT. SVP attenuated the PCPA-induced ultra-structural changes and alterations of 5-HT content in the mouse brain. The study suggests the involvement of 5-HT in the 6 Hz psychomotor seizures and in the mechanisms of action of SVP against such seizures in mice. </jats:p>

Regular Aerobic Exercise Attenuates Pain and Anxiety in Mice by Restoring Serotonin-Modulated Synaptic Plasticity in the Anterior Cingulate Cortex

“…Serotonin (S4244; Selleck, USA), 4-chloro-DL-phenylalanine (PCPA) (S4586; Selleck, USA), WAY100635 (S2663; Selleck, USA), and SB269970 (S2849; Selleck, USA) were purchased from Selleck. The concentrations of these drugs and vehicle for cannular delivery in the present study were in accordance with those described previously (27)(28)(29)(30). A c-Fos (1:3000; 2250S; Cell Signaling Technology) antibody was purchased from Cell Signaling Technology.…”

“…3B). Serotonin in the ACC was depleted by five consecutive pretreatments of parachlorophenylalanine (PCPA, 300 mg•kg −1 •d −1 ) as previously described (28). Next, the subjects were subdivided into PCPA and vehicle groups.…”

Central Histaminergic Signaling, Neural Excitability and Epilepsy

“…Moreover, it has been found that histamine content was decreased in amygdala of amygdala kindling-induced focal seizure with secondary generalized seizure (Kamei, Ishizawa, Kakinoki & Fukunaga, 1998). Besides, a reduction of brain histamine level has been found in transauricular kindling rats (Li, Liu, Zhu, Zhou & Chen, 2006), and 6-Hz stimulation mice (Jahan, Pillai & Vohora, 2017). In the audiogenic DBA/2 mice, a decrease of histamine level has been detected in the hypothalamus (Tuomisto, Sturman, Freeman & Tarhanen, 2003).…”