In this study we examined the spatial relationship of GABA-containing and GnRH-containing neurons by immunocytochemistry and in situ hybridization in larval and adult brains of sea lamprey, Petromyzon marinus. In immunocytochemical studies, GABA-containing neurons were detected early in lamprey development, by day 20 post-fertilization. At this time point, one population of GABA-containing neurons was visualized in the hypothalamus and preoptic area, and another population was located in the olfactory bulb of the telencephalon. By day 30 after fertilization, after the GABA neurons were detected, GnRH-containing neurons were visualized in the preoptic area/rostral hypothalamus region, adjacent to the GABA-containing neurons in the wall of the third ventricle. Similarly, in adult lamprey brains distinct populations of both GABA- and GnRH-containing neurons were located in the hypothalamus adjacent to the third ventricle. To further establish a proximate relationship between GABA and GnRH, the mRNA for glutamate decarboxylase (GAD), the enzyme catalyzing GABA synthesis from glutamate, and GnRH were examined by in situ hybridization in the brains of larval lamprey. These studies also showed that GnRH and GAD are produced in cell populations in and around the third ventricle of the hypothalamus. This close spatial relationship of GABA neurons and GnRH neurons provides a basis for a regulatory role of GABA on GnRH neurons in the sea lamprey.

Introduction: Critically ill patients commonly present to the ED and require aggressive resuscitation. Patient transfer to an ICU environment in an expedient manner is considered optimal care. However, this patient population may remain in the ED for prolonged periods of time. The goal of this study is to describe the ED length of stay, and the invasive procedures performed in critically ill ED patients.

CLINICIAN'S CAPSULE What is known about the topic? Patients who die from poisoning are potential organ or tissue donors but may represent an under-referred population. What did this study ask? Do Canadian emergency physicians under-refer patients who die from poisoning for organ or tissue donation, and what characteristics influence referral rates? What did this study find? In a simulated context, poisoned patients were under-referred as potential organ or tissue donors, and both environmental and clinician characteristics influenced rates. Why does this study matter to clinicians? Understanding factors that affect donor referral may decrease the morbidity and mortality for patients waiting for organ or tissue donation.

Our data support the theory that children who present with trauma tend to be those with extrinsic or intrinsic factors that increase trauma risk. We have demonstrated a direct relationship between emergency department visit counts for trauma with future trauma occurrence risk. This relationship is present at all ages and in both males and females. The emergency trauma visit count is an easily obtained measure that has merit as an index to identify higher-risk children for possible intervention strategies. Further work is needed.

No abstract