AI Article Synopsis
- The dorsal (DR) and median raphe (MR) nuclei house cell bodies that produce serotonin (5-HT), which influences emotional behavior through connections to the forebrain limbic areas.
- Recent advancements in electrophysiological techniques allowed researchers to analyze the properties of 5-HT and non-5-HT neurons in both nuclei, revealing both similarities and significant differences in their characteristics.
- Findings indicated that MR 5-HT neurons had distinct responses compared to DR 5-HT neurons, particularly regarding 5-HT(1A) receptor activation, highlighting the importance of these circuits in understanding emotional regulation and potential mental health conditions.
Article Abstract
The dorsal (DR) and median raphe (MR) nuclei contain 5-hydroxytryptamine (serotonin, 5-HT) cell bodies that give rise to the majority of the ascending 5-HT projections to the forebrain limbic areas that control emotional behavior. In the past, the electrophysiological identification of neurochemically identified 5-HT neurons has been limited. Recent technical developments have made it possible to re-examine the electrophysiological characteristics of identified 5-HT- and non-5-HT-containing neurons. Visualized whole cell electrophysiological techniques in combination with fluorescence immunohistochemistry for 5-HT were used. In the DR, both 5-HT- and non-5-HT-containing neurons exhibited similar characteristics that have historically been attributed to putative 5-HT neurons. In contrast, in the MR, the 5-HT-and non-5-HT-containing neurons had very different characteristics. Interestingly, the MR 5-HT-containing neurons had a shorter time constant and larger afterhyperpolarization (AHP) amplitude than DR 5-HT-containing neurons. The 5-HT(1A) receptor-mediated response was also measured. The efficacy of the response elicited by 5-HT(1A) receptor activation was greater in 5-HT-containing neurons in the DR than the MR, whereas the potency was similar, implicating greater autoinhibition in the DR. Non-5-HT-containing neurons in the DR were responsive to 5-HT(1A) receptor activation, whereas the non-5-HT-containing neurons in the MR were not. These differences in the cellular characteristics and 5-HT(1A) receptor-mediated responses between the MR and DR neurons may be extremely important in understanding the role of these two 5-HT circuits in normal physiological processes and in the etiology and treatment of pathophysiological states.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830647 | PMC |
| http://dx.doi.org/10.1152/jn.00744.2003 | DOI Listing |
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Article Synopsis
- The dorsal (DR) and median raphe (MR) nuclei house cell bodies that produce serotonin (5-HT), which influences emotional behavior through connections to the forebrain limbic areas.
- Recent advancements in electrophysiological techniques allowed researchers to analyze the properties of 5-HT and non-5-HT neurons in both nuclei, revealing both similarities and significant differences in their characteristics.
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