Proceedings of the Australian Physiological and Pharmacological Society Symposium: The Hypothalamus HYPOTHALAMIC PARAVENTRICULAR NUCLEUS AND CARDIOVASCULAR REGULATION

Clinical and Experimental Pharmacology and Physiology - Tập 28 Số 1-2 - Trang 95-99 - 2001
Emilio Badoer1
1Department of Medical Laboratory Science, RMIT University, Melbourne, Victoria, Australia.

Tóm tắt

SUMMARY1. The hypothalamic paraventricular nucleus (PVN) is an important integrative site within the brain composed of magnocellular and parvocellular neurons. It is known to influence sympathetic nerve activity.2. The parvocellular PVN contains neurons that project to the intermediolateral cell column of the thoraco–lumbar spinal cord (IML). This defines the PVN as an autonomic ‘premotor nucleus’, one of only five present within the brain.3. Another projection arising from the PVN is a prominent innervation of the pressor region of the rostral ventrolateral medulla (RVLM), also a premotor nucleus. The distribution of the PVN neurons projecting to the RVLM is similar to that of the PVN neurons that project to the IML.4. It has been found that up to 30% of spinally projecting neurons in the PVN also send collaterals to the RVLM. Thus, there are neurons in the PVN that can: (i) directly influence sympathetic nerve activity (via PVN–IML connections); (ii) indirectly influence sympathetic nerve activity (via PVN–RVLM connections); and (iii) both directly and indirectly influence sympathetic nerve activity (via neurons with collaterals to the IML and RVLM).5. In the rat, results of studies using the protein Fos to identify activated neurons in the brain suggest that neurons in the PVN with projections to the IML or RVLM may be activated by decreases in blood volume.6. In conclusion, the PVN can influence sympathetic nerve activity. Within the PVN are neurons with anatomical connections that enable them to affect sympathetic nerve activity either directly, indirectly or via both mechanisms (via collaterals). Studies that have examined the role of specific subgroups within the PVN suggest that PVN neurons with connections to the IML or to the RVLM may play a role in the reflex changes in sympathetic nerve activity that are involved in blood volume regulation.

Từ khóa


Tài liệu tham khảo

10.1146/annurev.ne.06.030183.001413

10.1016/0304-3940(75)90004-X

10.1016/0165-1838(87)90094-4

Kannan H, 1987, Increase in sympathetic outflow by paraventricular nucleus stimulation in awake rats., Am. J. Physiol., 256, R1325

Porter JP., 1988, Electrical stimulation of paraventricular nucleus increases plasma renin activity., Am. J. Physiol., 254, R325

10.1016/0165-0270(82)90036-X

Malpas S, 1994, Role of vasopressin in sympathetic response to paraventricular nucleus stimulation in anaesthetised rats., Am. J. Physiol., 266, R228

10.1152/physrev.1994.74.2.323

10.1002/cne.901940306

10.1016/s0006-8993(98)00587-3

10.1016/0006-8993(92)90150-8

10.1016/0006-8993(93)91403-F

10.1016/0304-3940(93)90821-2

10.1016/s0306-4522(97)00232-7

10.1016/s0165-1838(98)00124-6

10.1016/s0006-8993(98)00140-1

10.1016/S0006-8993(98)00560-5

10.1152/ajprenal.1985.248.1.F15

10.1111/j.1748-1716.1980.tb06632.x

10.1152/ajpregu.1998.274.2.R383

Morita H, 1985, Effects of volume expansion on renal nerve activity, renal blood flow, and sodium and water excretion in conscious dogs., Am. J. Physiol., 249, F680

10.1016/0165-1838(94)90117-1

10.1016/0165-1838(93)90331-N

10.1016/0165-1838(88)90018-5

10.3109/10641969509087066