Spike-based dynamic computing with asynchronous sensing-computing neuromorphic chip.

By mimicking the neurons and synapses of the human brain and employing spiking neural networks on neuromorphic chips, neuromorphic computing offers a promising energy-efficient machine intelligence. How to borrow high-level brain dynamic mechanisms to help neuromorphic computing achieve energy advantages is a fundamental issue. This work presents an application-oriented algorithm-software-hardware co-designed neuromorphic system for this issue. First, we design and fabricate an asynchronous chip called "Speck", a sensing-computing neuromorphic system on chip. With the low processor resting power of 0.42mW, Speck can satisfy the hardware requirements of dynamic computing: no-input consumes no energy. Second, we uncover the "dynamic imbalance" in spiking neural networks and develop an attention-based framework for achieving the algorithmic requirements of dynamic computing: varied inputs consume energy with large variance. Together, we demonstrate a neuromorphic system with real-time power as low as 0.70mW. This work exhibits the promising potentials of neuromorphic computing with its asynchronous event-driven, sparse, and dynamic nature.

Gonadotropin-releasing hormone-secreting neuron development and function: an update.

The coordinated and pulsatile secretion of gonadotropin-releasing hormone (GnRH) plays a central role in vertebrate reproductive function. The development of the hypothalamo-pituitary-gonadal (HPG) axis is characterized by a complex network of molecular signals that controls, at first, migration of the GnRH neurons along the nose, through the cribriform plate, up to the frontal lobe. This migratory process is orchestrated by several factors including anosmin-1, polysialylated form of the neural cell adhesion molecule, γ-amino butyric acid, hepatocyte growth factor, chemokines, cytokines and semaphorins. Moreover, antimüllerian hormone, growth hormone and insulin-like growth factor-1 were recently reported to modulate immature GnRH neuron migration in vitro. Once arrived in the forebrain, GnRH neurons mainly localize in the medial preoptic area and their axon elongation, mediated by fibroblast growth factor receptor 1 and semaphorin 7A signaling, is essential for GnRH secretion. The physiological pulsatile release of GnRH is controlled by central and peripheral factors, including kisspeptin, neurokinin B and dynorphin from KNDy neurons, and sex steroids and leptin, respectively. GnRH pulsatile release into the hypothalamus-pituitary blood portal system stimulates luteinizing hormone and follicle-stimulating hormone secretion into the general circulation. Such knowledge also results crucial for understanding of the molecular bases of congenital and acquired dysfunction of the HPG axis, which imply severe pathological consequences, such as GnRH deficiency or congenital hypogonadotropic hypogonadism, characterized by incomplete or absent puberty and infertility.

Cameroonian Spice Extracts Modulate Molecular Mechanisms Relevant to Cardiometabolic Diseases in SW 872 Human Liposarcoma Cells.

The molecular pathophysiology of cardiometabolic diseases is known to be influenced by dysfunctional ectopic adipose tissue. In addition to lifestyle improvements, these conditions may be managed by novel nutraceutical products. This study evaluatedthe effects of 11 Cameroonian medicinal spice extracts on triglyceride accumulation, glucose uptake, reactive oxygen species (ROS) production and interleukin secretion in SW 872 human adipocytes after differentiation with 100 µM oleic acid. Triglyceride content was significantly reduced by all spice extracts. Glucose uptake was significantly increased by Tetrapleura tetraptera, Aframomum melegueta and Zanthoxylum leprieurii. Moreover, Xylopia parviflora, Echinops giganteus and Dichrostachys glomerata significantly reduced the production of ROS. Concerning pro-inflammatory cytokine secretion, we observed that Tetrapleura tetraptera, Echinops giganteus, Dichrostachys glomerata and Aframomum melegueta reduced IL-6 secretion. In addition, Xylopia parviflora, Monodora myristica, Zanthoxylum leprieurii, and Xylopia aethiopica reduced IL-8 secretion, while Dichrostachys glomerata and Aframomum citratum increased it. These findings highlight some interesting properties of these Cameroonian spice extracts in the modulation of cellular parameters relevant to cardiometabolic diseases, which may be further exploited, aiming to develop novel treatment options for these conditions based on nutraceutical products.