Our estimates of occupancy suggest that temperature, SC, and pH have some importance in structuring stream salamander distribution.”
“GnRH neuron activity is dependent on gonadal steroid hormone feedback. Altered synaptic input may be one mechanism by which steroids
modify GnRH neuron activity. In other neuronal populations, steroid hormones have been shown to elicit profound effects on dendritic spine density, a measure of excitatory synaptic input. The present study examined gonadal steroid feedback effects on GnRH neuron spine density in female GnRH-green fluorescent protein (GFP) mice. Immunocytochemical labeling of GFP in this model reveals fine morphological details of GnRH neurons. Spine density and ICG-001 purchase other features were quantified by confocal analysis. Ovariectomy resulted in a significant reduction in somatic spine density (27%, P < 0.05) compared with sham-operated diestrous females. However, dendritic spine density was unaltered. Positive feedback effects of estradiol on spine density were investigated using a protocol to mimic the GnRH/LH surge.
Ten GnRH-GFP mice underwent an established protocol, receiving either estradiol benzoate (1 mu g per 20 g body weight) or vehicle (n = 5/group) Selleckchem MS 275 32 h prior to being killed during the expected surge. Double-label immunofluorescence showed that all estradiol-treated females expressed cFos in a subpopulation of GnRH neurons. Spine density was determined by confocal analysis of activated (cFos-positive, n = 10 neurons/animal) and nonactivated (cFos-negative, n = 10 neurons/animal) GnRH neurons from estradiol-treated animals and for GnRH neurons (n = 20 neurons/animal)
from nonsurged controls (all cFos negative). Activated GnRH neurons (cFos positive) showed a dramatic 60% increase in total spine density (0.78 +/- 0.06 spines/mu m) compared with nonactivated GnRH neurons (0.50 +/- 0.01 spines/mu m) in estradiol-treated animals (P < 0.001). Both somatic and dendritic spine density was significantly increased. Spine density was not different between nonactivated GnRH neurons from surged animals (0.50 +/- 0.01 spines/mu m) and GnRH neurons from nonsurged animals (0.51 +/- 0.06 spines/mu m). These data demonstrate Crenolanib in vitro that positive feedback levels of estradiol stimulate a robust increase in spine density specifically in those GnRH neurons that are activated at the time of the GnRH/LH surge. (Endocrinology 152: 4906-4914, 2011)”
“Nickel-containing alloys are in common use for dental restorations, but tend to corrode and release Ni(II) in service. Ni(II) increases secretion of several inflammatory cytokines from activated monocytic cells, suggesting that nickel alloys may exaggerate inflammatory responses in adjacent periodontal tissues.