Regulation of behaviour by the nuclear receptor TLX.

The orphan nuclear receptor Tlx (Nr2e1) is a key regulator of both embryonic and adult hippocampal neurogenesis. Several different mouse models have been developed which target Tlx in vivo including spontaneous deletion models (from birth) and targeted and conditional knockouts. Although some conflicting findings have been reported, for the most part studies have demonstrated that Tlx is important in regulating processes that underlie neurogenesis, spatial learning, anxiety-like behaviour and interestingly, aggression. More recent data have demonstrated that disrupting Tlx during early life induces hyperactivity and that Tlx plays a role in emotional regulation. Moreover, there are sex- and age-related differences in some behaviours in Tlx knockout mice during adolescence and adulthood. Here, we discuss the role of Tlx in motor-, cognitive-, aggressive- and anxiety-related behaviours during adolescence and adulthood. We examine current evidence which provides insight into Tlx during neurodevelopment, and offer our thoughts on the function of Tlx in brain and behaviour. We further hypothesize that Tlx is a key target in understanding the emergence of neurobiological disorders during adolescence and early adulthood.

What do recent human studies tell us about the association between anaesthesia in young children and neurodevelopmental outcomes?

Anaesthetic and sedative drugs transiently disrupt normal neural activity to facilitate healthcare procedures in children, but they can also cause long-term brain injury in experimental animal models. The US Food and Drug Administration (FDA) has recently advised that repeated or lengthy exposures to anaesthetic and sedative drugs prior to 3 yr of age have the potential to harm the development of children's brains and added warnings to these drug labels. Paediatric anaesthesia toxicity could represent a significant public health issue, and concern about this potential injury in children has become an important issue for families, paediatric clinicians and healthcare regulators. Since late 2015, important new data from five major clinical studies have been published. This narrative review aims to provide a brief overview of the preclinical and clinical literature, including a comprehensive review of these recent additions to the human literature. We integrate these new data with prior studies to provide further insights into how these clinical findings can be applied to children.

Surgical recontouring of a panfacial fibro-osseous deformity.

A report of the surgical management of a patient with a panfacial fibro-osseous deformity resulting from fibrous dysplasia, hyperparathyroidism, or both, is presented as a sequel to a previous article discussing the initial work-up and diagnostic considerations. The literature pertinent to the surgical correction of fibro-osseous lesions irformed through an oral approach. Regrowth of the lesion after three years was minimal in the maxilla and approximately 20% in the mandible.

Behavioral and toxicological studies of cyclopentanoid monoterpenes from Nepeta cataria.

Two samples of catnip oil were analyzed by tic, gc, and hplc; the results indicated the presence of 23 components. Fractionation of the commercial sample of catnip oil by either distillation or gc yielded 40% nepetalactone and 43% nepetalic acid. Catnip oil, nepetalic acid, and a nepetalactone-enriched fraction were evaluated for toxicological and behavioral effects in mice and rats. The LD50 of catnip oil, the nepetalactone-enriched fraction, and nepetalic acid were found in mice to be: 1300 mg/kg, 1550 mg/kg and 1050 mg/kg, respectively. Catnip oil (500 mg/kg) and nepetalic acid (62.5 mg/kg) were found to significantly increase hexobarbital sleeping time in mice. Rats trained on a Sidman avoidance schedule showed a significant decrease in performance following intraperitoneal injections of catnip oil (500--750 mg/kg), nepetalic acid (125--250 mg/kg), and the nepetalactone-enriched fraction (500--750 mg/kg). Rats trained on the same avoidance schedule developed behavioral tolerance after daily injections of 750 mg/kg catnip oil.