Neuroendocrine responses to an emotional stressor: evidence for involvement of the medial but not the central amygdala

European Journal of Neuroscience - Tập 11 Số 7 - Trang 2312-2322 - 1999
Christopher V. Dayas1, Kathryn M. Buller2, Trevor A. Day2
1Department of Physiology, University of Queensland, Brisbane, QLD 4072, Australia.
2Department of Physiology and Pharmacology, University of Queensland, Brisbane, QLD 4072, Australia

Tóm tắt

AbstractThe amygdala plays a pivotal role in the generation of appropriate responses to emotional stimuli. In the case of emotional stressors, these responses include activation of the hypothalamic–pituitary–adrenal (HPA) axis. This effect is generally held to depend upon the central nucleus of the amygdala, but recent evidence suggests a role for the medial nucleus. In the present study, c‐fos expression, amygdala lesion and retrograde tracing experiments were performed on adult rats in order to re‐evaluate the role of the central as opposed to the medial amygdala in generating neuroendocrine responses to an emotional stressor. Brief restraint (15 min) was used as a representative emotional stressor and was found to elicit c‐fos expression much more strongly in the medial than central nucleus of the amygdala; relatively few Fos‐positive cells were seen in other amygdala nuclei. Subsequent experiments showed that ibotenic acid lesions of the medial amygdala, but not the central amygdala, greatly reduced restraint‐induced activation of cells of the medial paraventricular nucleus, the site of the tuberoinfundibular corticotropin‐releasing factor cells that constitute the apex of the HPA axis. Medial amygdala lesions also reduced the activation of supraoptic and paraventricular nucleus oxytocinergic neurosecretory cells that commonly accompanies stress‐induced HPA axis activation in rodents. To assess whether the role of the medial amygdala in the control of neuroendocrine cell responses to emotional stress might involve a direct projection to such cells, retrograde tracing of amygdala projections to the paraventricular nucleus was performed in combination with Fos immunolabelling. This showed that although some medial amygdala cells activated by exposure to an emotional stressor project directly to the paraventricular nucleus, the number is very small. These findings provide the first direct evidence that it is the medial rather than the central amygdala that is critical to hypothalamic neuroendocrine cell responses during an emotional response, and also provide the first evidence that the amygdala governs oxytocin as well as HPA axis responses to an emotional stressor.

Từ khóa


Tài liệu tham khảo

10.1038/30982

10.1016/0306-4522(92)90322-S

10.1159/000124652

10.1159/000124701

10.1016/S0306-4522(97)00577-0

10.1016/S0079-6123(08)61881-6

10.1016/S0006-8993(96)01281-4

10.1046/j.1365-2826.1998.00231.x

10.1016/0304-3940(87)90141-8

10.1159/000126301

10.1046/j.1365-2826.1997.00593.x

10.1002/cne.903600203

10.1016/0306-4530(87)90007-2

10.1046/j.1365-2826.1998.00179.x

10.1016/0306-4522(94)00532-A

10.1016/0006-8993(85)90045-9

10.1016/0306-4522(90)90126-O

10.1016/0306-4522(94)00355-9

10.1002/cne.902740107

10.1016/0006-8993(95)01486-1

10.1159/000124442

10.1523/JNEUROSCI.14-02-00897.1994

10.1016/S0006-8993(09)90005-1

10.1016/0149-7634(94)00062-6

10.1016/0006-8993(84)91257-5

10.1016/0024-3205(84)90241-8

10.1159/000124487

Gray T.S., 1996, Stress, Neuropeptides, and Systemic Disease, 37

10.1159/000125260

10.1159/000126400

10.1016/S0166-2236(96)10069-2

10.1111/j.1365-2826.1994.tb00604.x

10.1097/00001756-199210000-00007

10.1016/0006-8993(93)90199-W

10.1016/S0149-7634(05)80175-7

10.1002/(SICI)1096-9861(19980525)395:1<53::AID-CNE5>3.0.CO;2-G

10.1038/41097

10.1159/000123566

10.1016/0306-4522(94)90439-1

10.1002/(SICI)1096-9861(19980406)393:2<244::AID-CNE8>3.0.CO;2-2

10.1046/j.1460-9568.1998.00011.x

10.1016/0361-9230(95)00017-8

10.1016/0169-328X(94)90063-9

10.1016/0006-8993(92)91503-7

10.1016/S0166-2236(97)01125-9

10.1111/j.1749-6632.1994.tb39279.x

10.3109/10253899709013746

10.1016/0031-9384(91)90016-H

10.1111/j.1365-2826.1992.tb00196.x

Roozendaal B., 1997, The role of the central amygdala in stress and adaption. Acta Physiol., Scand. (Suppl.640), 51

10.1002/cne.902180202

10.1016/S0361-9230(81)80068-8

10.1523/JNEUROSCI.15-12-07979.1995

10.1016/S0166-2236(98)01265-X

10.1159/000123454

10.1016/0304-3940(96)12978-5

10.1016/0306-4522(81)90190-1

10.1159/000125856

Xu Y., 1998, Role of the central amygdala in HPA axis, oxytocin and central catecholamine responses to systemic IL‐1β., Eur. J. Neurosci, 10, 295

Thông tin
Thông tin xuất bản

European Journal of Neuroscience

Tập 11 Số 7

2312-2322

Thông tin tác giả