Clomipramine increases the responsiveness of raphe-cortical neurons in the rat.

Neuropsychobiology

Departamento de Fisiología, Universidad Veracruzana, México.

Published: December 1993

The cerebral cortex of the rat possesses 5-HT1A receptor subtype; however, whether the activation of this receptor by dorsal raphe nucleus stimulation produces a similar action on neuronal cortical firing as antidepressants acting on serotonin (5-HT) function is unknown. Single-unit extracellular recordings were obtained from parietal cortex in rats in which dorsal raphe nucleus or cerebellar peduncle was stimulated. Results compared groups long-term treated with clomipramine (1.25 mg/kg i.p., twice a day, during 30 days) or saline (0.15 ml i.p., twice a day, during 30 days). Amplitude of traces, firing rate, and response to treatment with clomipramine proved to be different between cortical neurons responding to dorsal raphe nucleus or cerebellar peduncle stimulation. Clomipramine increased a long-lasting cortical suppression of firing elicited by dorsal raphe nucleus stimulation. Obtained data suggests that the responses of nearby cortical neurons containing different kinds of 5-HT receptors may relate to the involved pathways and that clomipramine seems to act on 5-HT1A receptor subtype.

Download full-text PDF

Source
http://dx.doi.org/10.1159/000118981DOI Listing

Publication Analysis

Top Keywords

dorsal raphe
16
raphe nucleus
16
5-ht1a receptor
8
receptor subtype
8
nucleus stimulation
8
nucleus cerebellar
8
cerebellar peduncle
8
day days
8
cortical neurons
8
clomipramine
5

Similar Publications

The serotonergic raphe magnus (RMg) and dorsal raphe (DR) nuclei are crucial pain-regulating structures, which nociceptive activity is shown to be altered in gut pathology, but the underlying neuroplastic changes remain unclear. Considering the importance of 5-HT1A receptors in modulating both pain and raphe neuronal activity, in this study, we aimed to determine whether 5-HT1A-dependent visceral and somatic nociceptive processing within the RMg and DR is modified in postcolitis conditions. In anaesthetised male Wistar rats, healthy control and recovered from TNBS-induced colitis, the microelectrode recordings of RMg and DR neuron responses to noxious colorectal distension (CRD) or tail squeezing (TS) were performed prior and after intravenous administration of 5-HT1A agonist, buspirone.

View Article and Find Full Text PDF

Effect of antidepressants and social defeat stress on the activity of dorsal raphe serotonin neurons in free-moving animals.

J Pharmacol Sci

February 2025

Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan; Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, 565-0871, Japan; Project for Neural Networks, Drug Innovation Center, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, 565-0871, Japan. Electronic address:

Major depressive disorder (MDD) is among the most common mental disorders worldwide and is characterized by dysregulated reward processing associated with anhedonia. Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for MDD; however, their onset of action is delayed. Recent reports have shown that serotonin neurons in the dorsal raphe nucleus (DRN) are activated by rewards and play a vital role in reward processing.

View Article and Find Full Text PDF

Heat acclimation defense against exertional heat stroke by improving the function of preoptic TRPV1 neurons.

Theranostics

January 2025

Department of Critical Care Medicine and Department of Anaesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China, 710032.

Record-breaking heatwaves caused by greenhouse effects lead to multiple hyperthermia disorders, the most serious of which is exertional heat stroke (EHS) with the mortality reaching 60 %. Repeat exercise with heat exposure, termed heat acclimation (HA), protects against EHS by fine-tuning feedback control of body temperature (Tb), the mechanism of which is opaque. This study aimed to explore the molecular and neural circuit mechanisms of the HA training against EHS.

View Article and Find Full Text PDF

Non-image forming (NIF) pathways, a specialized branch of retinal circuitry, play a crucial role supporting physiological and behavioral processes, including circadian rhythmicity. Among the NIF regions, the dorsal raphe nucleus (DRN), a midbrain serotonergic cluster of neurons, is also devoted to circadian functions. Despite indirectly send photic inputs to circadian centers and modulating their activities, little is known about the organization of retina-DRN circuits in primate species.

View Article and Find Full Text PDF

A distributed subcortical circuit linked to instrumental information-seeking about threat.

Proc Natl Acad Sci U S A

January 2025

Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of Oxford, Oxford OX1 3TA, United Kingdom.

Daily life for humans and other animals requires switching between periods of threat- and reward-oriented behavior. We investigated neural activity associated with spontaneous switching, in a naturalistic task, between foraging for rewards and seeking information about potential threats with 7T fMRI in healthy humans. Switching was driven by estimates of likelihood of threat and reward.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!