|
|
||||||||
1. Effects of electrical stimulation of hypothalamic ventromedial nucleus (v.m.n.) on the lordosis reflex of female rats were examined in ovariectomized and oestrogen-primed animals with chronically implanted electrodes. 2. Lordosis triggered either by manual cutaneous stimulation or by male mounting, was facilitated by electrical stimulation of the v.m.n. 3 A gradual increase in lordosis performance followed a relatively long period of stimulation; never less than 15 min and usually about 1 hr of stimulation was necessary for maximum facilitation. Following the termination of stimulation, the performance returned gradually to the control level during a 5--8 hr period. 4. The optimal frequency of stimulation was between 10 and 30 Hz. Threshold for effective facilitation was, on the average, 12.5 microA. 5. Stimulation tended to induce larger facilitation when applied to the lateral side of v.m.n. 6. Pre-treatment with oestrogen was necessary to obtain facilitation by v.m.n. stimulation. The threshold dosage of oestrogen was 2.5 microgram per animal. 7. Stimulation was effective in adrenalectomized rats, in dexamethasone-primed animals, and in rats pre-treated with exogenous progesterone. Thus, adrenal prodesterone release is not required for the v.m.n. facilitation of lordosis. 8. Medial preoptic stimulation with the same parameters suppressed the lordosis reflex. 9. The v.m.n. participates in the control of lordosis by a facilitatory output. The delay before facilitation implies that the v.m.n. is not in the direct reflex-arc for the execution of lordosis. Rather, a summation or interaction process with an unusually long time course is involved.
This article has been cited by other articles:
![]() |
H. B. Patisaul, A. E. Fortino, and E. K. Polston Sex Differences in Serotonergic But Not {gamma}-Aminobutyric Acidergic (GABA) Projections to the Rat Ventromedial Nucleus of the Hypothalamus Endocrinology, January 1, 2008; 149(1): 397 - 408. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Marson and A. Z. Murphy Identification of neural circuits involved in female genital responses in the rat: a dual virus and anterograde tracing study Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2006; 291(2): R419 - R428. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Musatov, W. Chen, D. W. Pfaff, M. G. Kaplitt, and S. Ogawa RNAi-mediated silencing of estrogen receptor {alpha} in the ventromedial nucleus of hypothalamus abolishes female sexual behaviors PNAS, July 5, 2006; 103(27): 10456 - 10460. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Zhou, D. W. Pfaff, and G. Chen Sex differences in estrogenic regulation of neuronal activity in neonatal cultures of ventromedial nucleus of the hypothalamus PNAS, October 11, 2005; 102(41): 14907 - 14912. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Segal, N. R. Stallings, C. E. Lee, L. Zhao, N. Socci, A. Viale, T. M. Harris, M. B. Soares, G. Childs, J. K. Elmquist, et al. Use of Laser-Capture Microdissection for the Identification of Marker Genes for the Ventromedial Hypothalamic Nucleus J. Neurosci., April 20, 2005; 25(16): 4181 - 4188. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. H. Calizo and L. M. Flanagan-Cato Hormonal-Neural Integration in the Female Rat Ventromedial Hypothalamus: Triple Labeling for Estrogen Receptor-{alpha}, Retrograde Tract Tracing from the Periaqueductal Gray, and Mating-Induced Fos Expression Endocrinology, December 1, 2003; 144(12): 5430 - 5440. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Tsukahara and K. Yamanouchi Sex Difference in Septal Neurons Projecting Axons to Midbrain Central Gray in Rats: A Combined Double Retrograde Tracing and ER-Immunohistochemical Study Endocrinology, January 1, 2002; 143(1): 285 - 294. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. H. Calizo and L. M. Flanagan-Cato Estrogen Selectively Regulates Spine Density within the Dendritic Arbor of Rat Ventromedial Hypothalamic Neurons J. Neurosci., February 15, 2000; 20(4): 1589 - 1596. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Daniels, R. R. Miselis, and L. M. Flanagan-Cato Central Neuronal Circuit Innervating the Lordosis-Producing Muscles Defined by Transneuronal Transport of Pseudorabies Virus J. Neurosci., April 1, 1999; 19(7): 2823 - 2833. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |