Pathways between striate cortex and subcortical regions in Macaca mulatta and Saimiri sciureus: Evidence for a reciprocal pulvinar connection

The efferent and afferent connections of striate cortex have been compared in Macaca mulatta and Saimiri sciureus monkeys after injecting striate cortex with a mixture of horseradish peroxidase and tritiated amino acids. Three reciprocal pathways were found in Macaca; they were between striate cortex and (i) all layers of the dorsal lateral geniculate nucleus; (ii) the inferior subdivision of pulvinar; and (iii) the lateral subdivision of pulvinar. In Saimiri the only recprocal pathway involved the dorsal lateral geniculate nucleus; the pulvinar received a heavy striate input but too few peroxidase-labeled neurons were found in pulvinar to demonstrate convincingly a projection to striate cortex. In both species the reticular and posterior nucleus of the thalamus and the superior colliculus receive striate input; in Saimiri the ventral lateral geniculate also receives a striate projection. In both species, neurons in the basal forebrain project to striate cortex. Striate cortex synaptic terminals in both dorsal lateral geniculate nucleus and pulvinar are topographically organized. Inferior and lateral subdivisions of pulvinar each contain a representation of central retina, and the fiber bundles separating the two subdivisions apparently mark the vertical meridian. The results of this experiment suggest that both retino-geniculate and retino-superior colliculus-pulvinar types of visual information may converge within the striate cortex.     

Food group intake and risk of subtypes of esophageal and gastric cancer

Incidence rates for adenocarcinomas of the esophagus and gastric cardia have been increasing rapidly, while rates for non-cardia gastric adenocarcinoma and esophageal squamous cell carcinoma have declined. We examined food group intake as a risk factor for subtypes of esophageal and gastric cancers in a multicenter, population-based case-control study in Connecticut, New Jersey and western Washington state. Associations between food groups and risk were estimated using adjusted odds ratios (OR), based on increasing intake of one serving per day. Total vegetable intake was associated with decreased risk of esophageal adenocarcinoma (OR = 0.85, 95% CI = 0.75, 0.96). Conversely, total meat intake was associated with increased risk of esophageal adenocarcinoma (OR = 1.43, 95% CI = 1.11, 1.83), gastric cardia adenocarcinoma (OR = 1.37, 95% CI = 1.08, 1.73) and noncardia gastric adenocarcinoma (OR = 1.39, 95% CI = 1.12, 1.71), with red meat most strongly associated with esophageal adenocarcinoma risk (OR = 2.49, 95% CI = 1.39, 4.46). Poultry was most strongly associated with gastric cardia adenocarcinoma (OR = 1.89, 95% CI = 1.15, 3.11) and noncardia gastric adenocarcinoma (OR = 1.90, 95% CI = 1.19, 3.03). High-fat dairy was associated with increased risk of both esophageal and gastric cardia adenocarcinoma. Higher intake of meats, particularly red meats, and lower intake of vegetables were associated with an increased risk of esophageal adenocarcinoma, while higher intake of meats, particularly poultry, and high-fat dairy was associated with increased risk of gastric cardia adenocarcinoma.     

VBAC: a medicolegal perspective

History has always been a series of pendulum swings, and there is perhaps no better example in obstetrics than that of vaginal birth after cesarean. Vaginal birth after cesarean (VBAC) rates rose steadily in the early 1990s. However, VBAC rates have declined dramatically over recent years, while the cesarean delivery rate has continued to rise unabated. Many physicians and hospitals are no longer offering trial of labor after cesarean, largely because of medicolegal concerns. This article explores the medical and legal risks of trial of labor after cesarean.     

Effect of musical experience on verbal memory in Williams syndrome: evidence from a novel word learning task

Williams syndrome (WS) is a neurogenetic developmental disorder characterized by an increased affinity for music, deficits in verbal memory, and atypical brain development. Music has been shown to improve verbal memory in typical individuals as well as those with learning difficulties, but no studies have examined this relationship in WS. The aim of our two studies was to examine whether music can enhance verbal memory in individuals with WS. In Study 1, we presented a memory task of eight spoken or sung sentences that described an animal and identified its group name to 38 individuals with WS. Study 2, involving another group of individuals with WS (n = 38), included six spoken or sung sentences that identified an animal group name. In both studies, those who had participated in formal music lessons scored significantly better on the verbal memory task when the sentences were sung than when they were spoken. Those who had not taken formal lessons showed no such benefit. We also found that increased enjoyment of music and heightened emotional reactions to music did not impact performance on the memory task. These compelling findings provide the first evidence that musical experience may enhance verbal memory in individuals with WS and shed more light on the complex relationship between aspects of cognition and altered neurodevelopment in this unique disorder.     

Polysynaptic excitatory postsynaptic potentials that trigger spasms after spinal cord injury in rats are inhibited by 5-HT1B and 5-HT1F receptors

Sensory afferent transmission and associated spinal reflexes are normally inhibited by serotonin (5-HT) derived from the brain stem. Spinal cord injury (SCI) that eliminates this 5-HT innervation leads to a disinhibition of sensory transmission and a consequent emergence of unusually long polysynaptic excitatory postsynaptic potentials (EPSPs) in motoneurons. These EPSPs play a critical role in triggering long polysynaptic reflexes (LPRs) that initiate muscles spasms. In the present study we examined which 5-HT receptors modulate the EPSPs and whether these receptors adapt to a loss of 5-HT after chronic spinal transection in rats. The EPSPs and associated LPRs recorded in vitro in spinal cords from chronic spinal rats were consistently inhibited by 5-HT(1B) or 5-HT(1F) receptor agonists, including zolmitriptan (5-HT(1B/1D/1F)) and LY344864 (5-HT(1F)), with a sigmoidal dose-response relation, from which we computed the 50% inhibition (EC(50)) and potency (-log EC(50)). The potencies of 5-HT receptor agonists were highly correlated with their binding affinity to 5-HT(1B) and 5-HT(1F) receptors, and not to other 5-HT receptors. Zolmitriptan also inhibited the LPRs and general muscle spasms recorded in vivo in the awake chronic spinal rat. The 5-HT(1B) receptor antagonists SB216641 and GR127935 and the inverse agonist SB224289 reduced the inhibition of LPRs by 5-HT(1B) agonists (zolmitriptan). However, when applied alone, SB224289, SB216641, and GR127935 had no effect on the LPRs, indicating that 5-HT(1B) receptors do not adapt to chronic injury, remaining silent, without constitutive activity. The reduction in EPSPs with zolmitriptan unmasked a large glycine-mediated inhibitory postsynaptic current (IPSC) after SCI. This IPSC and associated chloride current reversed at -73 mV, slightly below the resting membrane potential. Zolmitriptan did not change motoneuron properties. Our results demonstrate that 5-HT(1B/1F) agonists, such as zolmitriptan, can restore inhibition of sensory transmission after SCI without affecting general motoneuron function and thus may serve as a novel class of antispastic drugs.     

Epigenetic profiles of pre-diabetes transitioning to type 2 diabetes and nephropathy

AIM: To examine DNA methylation profiles in a longitudinal comparison of pre-diabetes mellitus(Pre-DM) subjects who transitioned to type 2 diabetes mellitus(T2DM).METHODS: We performed DNA methylation study in bisulphite converted DNA from Pre-DM(n = 11) at baseline and at their transition to T2 DM using Illumina Infinium Human Methylation27 Bead Chip, that enables the query of 27578 individual cytosines at Cp G loci throughout the genome, which are focused on the promoter regions of 14495 genes.RESULTS: There were 694 Cp G sites hypomethylated and 174 Cp G sites hypermethylated in progression from Pre-DM to T2 DM, representing putative genes involved in glucose and fructose metabolism, inflammation, oxidative and mitochondrial stress, and fatty acid metabolism. These results suggest that this high throughput platform is able to identify hundreds of prospective Cp G sites associated with diverse genes that may reflect differences in Pre-DM compared with T2 DM. In addition, there were Cp G hypomethylation changes associated with a number of genes that may be associated with development of complications of diabetes, such as nephropathy. These hypomethylation changes were observed in all of the subjects.CONCLUSION: These data suggest that some epigenomic changes that may be involved in the progression of diabetes and/or the development of complications may be apparent at the Pre-DM state or during the transition to diabetes. Hypomethylation of a number of genes related to kidney function may be an early marker for developing diabetic nephropathy.