Ncm, a Photolabile Group for Preparation of Caged Molecules: Synthesis and Biological Application.

Ncm, 6-nitrocoumarin-7-ylmethyl, is a photolabile protective group useful for making "caged" molecules. Ncm marries the reliable photochemistry of 2-nitrobenzyl systems with the excellent stability and spectroscopic properties of the coumarin chromophore. From simple, commercially available starting materials, preparation of Ncm and its caged derivatives is both quick and easy.

Excitation of primary afferent neurons by near-infrared light in vitro.

Near-infrared light therapy is an emerging neurostimulation technology, but its cellular mechanism of action remains unresolved. Using standard intracellular recording techniques, we observed that 5-10 ms pulses of 1889 nm light depolarized the membrane potential for hundreds of milliseconds in more than 85% of dorsal root ganglion and nodose ganglion neurons tested. The laser-evoked depolarizations (LEDs) exhibited complex, multiphasic kinetics comprising fast and slow components.

BKCa currents are enriched in a subpopulation of adult rat cutaneous nociceptive dorsal root ganglion neurons.

The biophysical properties and distribution of voltage-dependent, Ca(2+) -modulated K(+) (BK(Ca)) currents among subpopulations of acutely dissociated DiI-labeled cutaneous sensory neurons from the adult rat were characterized with whole-cell patch-clamp techniques. BK(Ca) currents were isolated from total K(+) current with iberiotoxin, charybdotoxin or paxilline. There was considerable variability in biophysical properties of BK(Ca) currents.

Inflammatory hyperalgesia: a role for the C-fiber sensory neuron cell body?

Unlabelled: Peripheral nerve injury increases the chemosensitivity and excitability of injured afferents, resulting in ectopic activity arising from within dorsal root ganglia. Studies of dissociated sensory ganglion neurons in vitro suggest afferent somata might be sensitized by persistent inflammation. However, it is unknown whether this inflammation-induced sensitization is manifest in somata within the intact ganglia.