No abstract

The metabolism and homeostasis of skeletal system has historically been regarded to be associated with the endocrine system. However, such view has been expanded with the recognition of several neural pathways playing important roles in the regulation of bone metabolism via central relays. In particular, bone metabolism and homeostasis has been reported to be precisely modulated by the central neural signaling. Initiated by the finding of leptin, the axis of neural regulation on bone expands rapidly. Semaphorin-plexin system play an important role in the crosstalk between osteoclasts and osteoblasts, a complex system has also been identified and includes neuropeptide Y and cannabinoids. These findings facilitate our understanding of the central neuropeptides and neural factors in the modulation of bone metabolism and homeostasis, and these neuronal pathways also represent an area of research scenario that identifies the novel regulation between brain and bone. These regulatory mechanisms correlate with other homeostatic networks and demonstrate a more intricate and synergetic bone biology than previously envisioned. As such, this review summarizes the current knowledge of the neural regulation of bone metabolism and homeostasis as well as its role in skeletal diseases, and discusses the emerging challenges presented in this field. This article is protected by copyright. All rights reserved.

Neural firing patterns are critical for specific information coding and transmission, and abnormal firing is implicated in a series of neural pathologies. Recent studies have indicated that enhanced burst firing mediated by T-type voltage-gated calcium channels (T-VGCCs) in specific neuronal subtypes is involved in several mental or neurological disorders such as depression and epilepsy, while suppression of T-VGCCs relieve related symptoms. Burst firing consists of groups of relatively high-frequency spikes separated by quiescence. Neurons in a variety of brain areas, including the thalamus, hypothalamus, cortex, and hippocampus, display burst firing, but the ionic mechanisms that generating burst firing and the related physiological functions vary among regions. In this review, we summarize recent findings on the mechanisms underlying burst firing in various brain areas, as well as the roles of burst firing in several mental and neurological disorders. We also discuss the ion channels and receptors that may regulate burst firing directly or indirectly, with these molecules highlighted as potential intervention targets for the treatment of mental and neurological disorders.