Sensory systems

A5-fibres are small diameter myelinated afferent fibres. As part of the pain sensory system they are present in... 

The function of a sensory system is to select suitable modalities from the multitude presented by the environment, and translate them into corresponding modalities of sensory information that are then projected and processed into the various parts and finally submitted to the central processing-unit, the brain. A working hypothesis of the mechanism by which the taste system senses chemical compounds is that macromolecules that are... 

The third is that the signal, or, rather, the causal sequence of its successors, travels through the various parts of the sensory system, undergoing various projecting and processing operations, until it ends its life at the central processing unit. ... 

Thus the neurotransmitter role of ATP is well established in the periphary and also in sensory systems but its importance in the CNS remains to be elucidated (see Burnstock 1996). That requires the development of more specific antagonists and methods of mapping its location. The strong linkage of its P2x receptors to calcium currents may also provide a role for ATP in more long-term effects such as plasticity and neuronal development and death. 

Graziadei P.P. (1990). Olfactory development. In Development of Sensory Systems in Mammals (Coleman R.L., ed.). Wiley, New York, pp. 519-567. 

Mozell M. and Homung D. (1984). Initial events influencing olfactory analysis. In Comparative Physiology of Sensory Systems (Bolis L., et al., eds.). Cambridge University Press. 

Nervous system disorders are diagnosed by examining the patient s mental status, cranial nerve function, motor system reflexes, and sensory systems. An electroencephalogram (EEG) tests higher brain and nervous system functions. 

In brain slices, even though no anesthesia is present, there is a reduction in both noradrenergic and other inputs to these cells (e.g., from sensory systems) thus most of these neurons become silent. Consistent with this interpretation is the fact that all presumed serotonergic neurons we have tested in the brain slice are uniformly activated by norepinephrine or the < ragonist phenylephrine, applied either iontophoretically or in the perfusion medium (51). Similarly, in... 

Ishii, T., Hirota, J. and Mombaerts, P. (2003) Combinational coexpression of neural and immune multigene families in mouse vomeronasal sensory systems. Curr. Biol. 13, 394-400. 

As with many macrosmatic mammals, rodents have two separate chemosensory systems, the main olfactory system (MOS) and accessory olfactory system (AOS), which respond to social odors. Importantly, these sensory systems differ not only in their peripheral morphology and central projections, but also in the types of chemosignals that they process (Meredith 1991). Sensory neurons of the MOS, which are located in the main olfactory epithelium and project to the main olfactory bulbs, process volatile chemicals and can detect odors at a distance. In contrast, sensory neurons of the AOS, which are located in the vomeronasal organs (VNO) and project to the accessory olfactory bulbs, primarily process large, non-volatile chemicals and require contact for stimulation (Meredith 1991). 

Olfaction, once thought to be a primitive sense, is now recognized as an elaborate sensory system that deploys a large family of odorant receptors to analyse the chemical environment. Interactions between these receptors and their diverse natural binding molecules (ligands) translate the world of odors into a neural code. Humans have about 350 odorant receptors. Rodents have more than a thousand. 

The EEG does have some disadvantages, or, more correctly, some limitations. It cannot provide information about the effects of toxicants on the integrity of sensory receptors or of sensory or motor pathways. As a corollary, it cannot provide an assessment of the effects of toxicants on sensory system capacities. Finally, the EEG does not provide specific information at the cellular level and therefore lacks the rigor to provide detailed mechanisms of action. 

Kaissling KE (1998) In Taddei-Ferretti C,Musio C (eds) From structure to information in sensory systems. World Scientific, River Edge, NJ, p 525... 

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