Medial emergency

Neuropeptide S (NPS) is a recently discovered bioactive peptide that has emerged as a new signaling molecule in the complex circuitry that modulates sleep-wakefulness and anxiety-like behavior. The peptide precursor is expressed most prominently in a novel nucleus located in the perilocus coeruleus, a brain structure with well-defined functions in arousal, stress, and anxiety. NPS was also found to induce anxiolytic-like behavior in a battery of four different tests of innate responses to stress. Infusion of NPS potently increases wakefulness and suppresses non-REM (NREM) and REM sleep (Xu et al, 2004). NPS binds to a G-protein-coupled receptor, the NPS receptor, with nanomolar affinity activation of the receptor mobilizes intracellular calcium. The NPS receptor is expressed throughout the brain, particularly in regions relevant to the modulation of sleep and waking, in the tuberomammillary region, lateral hypothalamus, and medial thalamic nuclei. 

Schematic diagram of the gustatory pathway in rodents. Taste receptor cells are innervated by one of three cranial nerves (VII, IX, or X), which project topographically into the rostral portion of nucleus of the solitary tract (NST). Cells within the NST send projections into the reticular formation (RF), through which connections are made to oral motor nuclei V, VII, and XII and the nucleus ambiguous (NA). Ascending fibers connect to the parabrachial nuclei (PbN) of the pons, from which two parallel pathways emerge. One pathway carries taste information to the insular cortex (IC) via the ventral posterior medial nucleus, parvicellularis (VPMpc), of the thalamus. The other pathway projects into areas of the limbic forebrain involved in food and water regulation, reinforcement, reward, and stress, including the lateral hypothalamus (LH), the central nucleus ofthe amygdala (CeA), and the bed nucleus of the stria terminalis (BST). These areas and the IC are interconnected and send descending projections back to both the PbN and NST...

Proceeding toward the interscalene area, the roots of C5 and C6 join together to form the upper trunk, the root of C7 emerges by itself as the intermediate trunk and, in the lower neck, the roots of C8 and Tl form the lower trunk of the plexus. More distally, in the supraclavicular region, each trunk gives off two divisional branches, named the anterior and posterior divisions, which innervate the flexor and extensor muscles of the upper extremity respectively. In the axilla, these divisions join in various combinations to form the cords of the brachial plexus. The relationship of the cords with the axillary artery determines their names the lateral, medial and posterior cords. The axillary and radial nerves originate from the posterior cord, the musculocutaneous and part of the median nerve arise from the lateral cord, vdiereas the other contribution of fibers to the median nerve and the ulnar nerve originate from the medial cord. 

Figure 8.26 Medial and lateral cracking under a conical indenter. When the lateral crack emerges at the surface a chip forms.

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