The Characteristics of Supramammillary Cells Projecting to the Hippocampus in Stress Response in the Rat.
10.4196/kjpp.2012.16.1.17
- Author:
Woong Ki CHOI
1
;
David WIRTSHAFTER
;
Hyun Jung PARK
;
Mi Sook LEE
;
Song HER
;
Insop SHIM
Author Information
1. Acupuncture & Meridian Science Research Center, College of Oriental Medicine, Kyung Hee University, Seoul 130-701, Korea. ishim@khu.ac.kr
- Publication Type:Original Article
- Keywords:
Immobilization stress;
Supramammillary region;
Hippocampus;
Fluorogold;
Immunohistochemistry
- MeSH:
Adrenocorticotropic Hormone;
Animals;
Axis, Cervical Vertebra;
Choline O-Acetyltransferase;
Dopamine;
gamma-Aminobutyric Acid;
Glutamate Decarboxylase;
Hippocampus;
Immobilization;
Immunohistochemistry;
Nitric Oxide;
Rats;
Serotonin;
Tyrosine 3-Monooxygenase
- From:The Korean Journal of Physiology and Pharmacology
2012;16(1):17-24
- CountryRepublic of Korea
- Language:English
-
Abstract:
The hypothalamus-pituitary-adrenocortex (HPA) axis is the central mediator of the stress response. The supramammillary (SuM) region is relatively unique among the hypothalamic structures in that it sends a large, direct projection to the hippocampal formation. It has been shown that mild stress could activate the SuM cells that project to the hippocampus. However, the role of these cell populations in modulating the stress response is not known. The present study examined the effect of stress on different populations of SuM cells that project to the hippocampus by injecting the fluorescent retrograde tracer, fluorogold (FG), into the hippocampus and utilizing the immunohistochemistry of choline acetyltransferase (ChAT), corticotrophin releasing factor (CRF), serotonin (5-HT), glutamate decarboxylase (GAD), tyrosine hydroxylase (TH) and NADPH-d reactivity. Immobilization (IMO) stress (2 hr) produced an increase in the expression of ChAT-immunoreactivity, and tended to increase in CRF, 5-HT, GAD, TH-immunoreactivity and nitric oxide (NO)-reactivity in the SuM cells. Fifty-three percent of 5-HT, 31% of ChAT and 56% of CRF cells were double stained with retrograde cells from the hippocampus. By contrast, a few retrogradely labeled cells projecting to the hippocampus were immunoreactive for dopamine, gamma-aminobutyric acid (GABA) and NO. These results suggest that the SuM region contains distinct cell populations that differentially respond to stress. In addition, the findings suggest that serotonergic, cholinergic and corticotropin releasing cells projecting to the hippocampus within the SuM nucleus may play an important role in modulating stress-related behaviors.
