Serotonin concentrations in the lumbosacral spinal cord of the adult rat following microinjection or dorsal surface application.

Application of neuroactive substances, including monoamines, is common in studies examining the spinal mechanisms of sensation and behavior. However, affected regions and time courses of transmitter activity are uncertain. We measured the spatial and temporal distribution of serotonin [5-hydroxytryptamine (5-HT)] in the lumbosacral spinal cord of halothane-anesthetized adult rats, following its intraspinal microinjection or surface application.

The role of BKCa channels in electrical signal encoding in the mammalian auditory periphery.

Large-conductance voltage- and Ca(2+)-activated K+ channels (BKCa) are involved in shaping spiking patterns in many neurons. Less is known about their role in mammalian inner hair cells (IHCs), mechanosensory cells with unusually large BKCa currents. These currents may be involved in shaping the receptor potential, implying crucial importance for the properties of afferent auditory signals.

Response properties of single auditory nerve fibers in the mouse.

The availability of transgenic and mutant lines makes the mouse a valuable model for study of the inner ear, and a powerful window into cochlear function can be obtained by recordings from single auditory nerve (AN) fibers. This study provides the first systematic description of spontaneous and sound-evoked discharge properties of AN fibers in mouse, specifically in CBA/CaJ and C57BL/6 strains, both commonly used in auditory research. Response properties of 196 AN fibers from CBA/CaJ and 58 from C57BL/6 were analyzed, including spontaneous rates (SR), tuning curves, rate versus level functions, dynamic range, response adaptation, phase-locking, and the relation between SR and these response properties.