Learn More
To define alterations of neuronal connectivity that occur during motor neuron degeneration, we characterized the function and structure of spinal circuitry in spinal muscular atrophy (SMA) model mice. SMA motor neurons show reduced proprioceptive reflexes that correlate with decreased number and function of synapses on motor neuron somata and proximal(More)
The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein and results in severe muscle weakness. In SMA mice, synaptic dysfunction of both neuromuscular junctions (NMJs) and central sensorimotor synapses precedes motor neuron cell death. To address whether this synaptic(More)
The effects of long-term treatment with physiological doses of oestradiol or oestradiol plus progesterone on plasma gonadotrophin levels and pituitary content of LH and gonadotrophin-releasing hormone (GnRH) receptors were studied in ovariectomized-hypothalamo-pituitary disconnected ewes given 250 ng pulses of GnRH every 2 h (i.v.). A pilot experiment(More)
Studies were undertaken to determine if the number of hypophyseal receptors for GnRH changes at the time of the preovulatory surge of LH in ewes. Concentrations of LH, FSH, progesterone, and estradiol in serum and concentrations of LH and FSH in pituitary were measured. The content of GnRH in the hypothalamus was also determined. Estrus was synchronized in(More)
A transnasal, transsphenoidal surgical approach was used to perform hypothalamic pituitary disconnections (HPD) in ovariectomized (OVX) ewes to examine the role of the hypothalamus in regulating the synthesis of anterior pituitary hormones. Ewes were killed at 1-3 days (n = 6), 1 week (n = 5), or 1 month (n = 5) after HPD. Pituitary glands were removed, and(More)
Several characteristics of the hypothalamo-hypophysial axis were examined after down-regulation of GnRH receptors and the desensitization which accompanies it in the ewe. Down-regulation of GnRH receptors, induced by i.v. infusion of GnRH (2.5 micrograms/h) for 24 h, resulted in a 50% decrease in the number of receptors for GnRH at the end of the infusion(More)
Bovine cDNA clones containing coding sequences for growth hormone, prolactin, alpha subunit, and luteinizing hormone beta (LH beta) have been used to quantitate their respective mRNA concentrations in anterior pituitary glands isolated from ovariectomized ewes, or from ovariectomized ewes treated for three weeks with estradiol. Concentrations of mRNAs for(More)