Projections from ventrolateral hypothalamic neurons containing progesterone receptors and somatostatin to the midbrain central gray in the female guinea pig

The goal of this study was to determine, by combining retrograde fluorescent tract tracing with double immunocytochemistry, whether neurons immunoreactive (IR) for both progesterone receptors (PR) and somatostatin (SOM) in the guinea-pig ventrolateral nucleus (VL) send their axons directly to the midbrain. Unilateral microinjections of true blue (TB) fluorescent dye were made into the midbrain central gray (MCG) of ovariectomized animals primed with estradiol to induce PR and injected intracerebroventricularly with colchicine to visualize SOM-IR neurons. The highest number of PR/SOM-IR neurons in the VL that projected to the midbrain was found when the fluorescent retrograde tracer was confined to the lateral region of the MCG at the mid-rostrocaudal level. More specifically, 29% of the progesterone target neurons containing SOM detected in the VL projected directly to the midbrain, accounting for 7% of the PR-IR neurons and for 9% of the SOM-IR neurons. These triple-labeled cells were found throughout the extent of the VL. Double-labeled cells also sent axons to the MCG and were either PR-IR (14%) or SOM-IR (12%). These results provide morphological evidence that a subset of the PR-IR neurons expressing SOM in the VL have long projections to the midbrain and suggest that the SOM system may modulate neural circuits involved in the regulation of steroid-influenced behaviors and neuroendocrine functions.     

Inhibition of lordosis behavior by intrahypothalamic infusion of a protein kinase G antagonist

Previous experiments demonstrated that intracerebroventricular infusion of the protein kinase G inhibitor KT5823 inhibits lordosis behavior in hormone-treated female rats. Present studies show that KT5823 attenuates lordosis in a dose-dependent manner when infused bilaterally into the ventromedial hypothalamus. Thus, activation of protein kinase G in the ventromedial hypothalamus is necessary for the expression of hormone-dependent lordosis behavior in female rats.     

Bryan人工椎间盘置换术对颈椎曲度影响的研究

目的观察不同手术时期Bryan人工椎间盘置换术后置换节段脊柱功能单位（functional spine unit,FSU）曲度变化情况。方法随访2003年12月～2007年12月接受单节段Bryan人工椎间盘置换术的患者,在侧位X线片上测量FSU角度变化。结果 60例患者获得随访,随访3～69个月,平均32个月,手术节段包括C3/C4节段2例,C4/C5节段14例,C5/C6节段41例,C6/C7节段3例。术前FSU平均曲度为0.3°,末次随访时为-0.5°（P〈0.05）。根据手术日期将全部病例分成早期（2003～2004年）、中期（2005年）和后期（2006～2007年）3组,统计分析发现早期病例随访时FSU后凸平均增加1.6°,后期病例FSU后凸平均增加仅0.1°,2组的FSU角度变化差异有统计学意义（P〈0.05）。结论 Bryan人工颈椎椎间盘置换术术后FSU后凸主要发生在早期病例,通过经验的积累和手术技术的改进可以避免术后FSU后凸。     

CNS arousal mechanisms bearing on sex and other biologically regulated behaviors

It now seems possible to move beyond analyzing only the mechanisms for specific sexual behaviors to the analysis of 'generalized arousal' that underlies all motivated behaviors. Our science has advanced sufficiently to attack mechanisms linking specific motivations to these general arousal mechanisms that intrinsically activate all biologically-regulated behaviors including ingestive behaviors. Learning from the well-developed reproductive behavior paradigm, we know that sex hormone effects on hypothalamic neurons have been studied to a point where receptor mechanisms are relatively well understood, a neural circuit for a sex steroid-dependent behavior has been worked out, and several functional genomic regulations have been discovered. Here we focus for the first time on three chemical systems that signal 'generalized arousal' and which impact hormone-dependent hypothalamic neurons of importance to sexual arousal: histamine, norepinephrine and enkephalin. Progress in linking generalized arousal to specific motivational mechanisms is reviewed.     

Effect of different sitting postures on lung capacity, expiratory flow, and lumbar lordosis

OBJECTIVE: To investigate the effect of sitting posture on lung capacity and expiratory flow (LC-EF) and lumbar lordosis. DESIGN: Repeated measures on 1 group of subjects in 4 postures. SETTING: Laboratory. PARTICIPANTS: Seventy able-bodied volunteers. INTERVENTIONS: Postures were assumed randomly: normal, with full ischial support and flat lumbar support; slumped, with the pelvis positioned in the middle of seat while leaning against the backrest; against the back part of the seat without ischial support (WO-BPS), with partially removed ischial support and an enhanced lumbar support; and standing. MAIN OUTCOME MEASURES: For LC-EF, forced vital capacity, maximum forced expiratory flow, forced expiratory volume in 1 second, and peak expiratory flow; and lumbar lordosis. RESULTS: All LC-EF measures in standing were significantly superior to those in slumped and normal sitting, and 4 measures were significantly higher than in WO-BPS. In slumped sitting, LC-EF significantly decreased from that in normal sitting. WO-BPS sitting significantly increased 4 of the LC-EF measures from those in the normal sitting. Lumbar lordosis was the highest in standing and progressively decreased in WO-BPS, normal, and slumped sitting. CONCLUSIONS: Slumped sitting significantly decreased LC-EF and lumbar lordosis. Because it increases the lumbar lordosis and promotes LC-EF, the WO-BPS posture may be a better seating option for people sitting for a prolonged time.     

The role of vaginal stimulation for the acquisition of conditioned place preference in female Syrian hamsters

This study investigated the importance of vaginal stimulation on conditioned place preference by sexual behavior in female Syrian hamsters. Hormonally primed female hamsters given vaginal masks and topical lidocaine prior to conditioning sessions were no different in their place preference conditioning compared to female controls with no vaginal mask or lidocaine. Control females not provided a sexually active male did not show any preference for either compartment of the conditioning apparatus. These results suggest that stimuli, in addition to vaginal stimulation, are effective in producing a place preference during the mating experience in female hamsters.     

Dissociation between the display of lordosis and soliciting behaviors in female rats with lesions of the dorsomedial pontine tegmentum

Lesions of the dorsomedial tegmentum (DMTL) between the midbrain pontine junction and the middle level of the pons effectively eliminate the induction by estrogen-progesterone of lordosis behavior in ovariectomized rats. However, soliciting behaviors such as ear wiggling and hopping were not inhibited by this type of lesion. The common damaged area in DMTL rats which failed to show lordosis was the medial periventricular gray. The lesions placed in the caudal pontine central gray were not effective in suppressing lordosis response. Lesions of the ventromedial tegmentum (VMTL) were also ineffective in suppressing lordosis. Most of the animals with the VMTL showed soliciting behaviors. In these rats, the incidence of lordosis and lordosis quotient (LQ) were comparable to those of sham operated rats. When bilateral lesions were placed in the lateral tegmentum region, the mean LQ and incidence of soliciting behavior were not significantly different from those of sham operated controls. These results suggest a clear dissociation of the regulatory mechanisms between the display of lordosis and soliciting behaviors at the pontine level.