This protocol details methods to identify and record from cutaneous primary afferent axons in an isolated mammalian skin–saphenous nerve preparation. The method is based on extracellular recordings of propagated action potentials from single-fiber receptive fields. Cutaneous nerve endings show graded sensitivities to various stimulus modalities that are quantified by adequate and controlled stimulation of the superfused skin with heat, cold, touch, constant punctate pressure or chemicals. Responses recorded from single-fibers are comparable with those obtained in previous in vivo experiments on the same species. We describe the components and the setting-up of the basic equipment of a skin–nerve recording station (few days), the preparation of the skin and the adherent saphenous nerve in the mouse (15–45 min) and the isolation and recording of neurons (approximately 1–3 h per recording). In addition, stimulation techniques, protocols to achieve single-fiber recordings, issues of data acquisition and action potential discrimination are discussed in detail.

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Phenotyping sensory nerve endings in vitro in the mouse

The phototransformations of phytochrome involve several intermediates. The initial photoreaction of the chromophore is followed by a series of dark relaxation states of the chromophore and apoprotein. The nature of these intermediates is outlined and they are discussed in relationship to our knowledge of the tetrapyrrole chromophore.

Phototransformations of phytochrome.

Photobiophysics and photobiochemistry of the heterogeneous phytochrome system

Actions de la noradrénaline et de l'ocytocine sur le transport actif de sodium et la perméabilité à de la peau de grenouille. Rôle du 3′,5′-AMP cyclique

Many amphibian species, including frogs, live alternatingly in aquatic and terrestrial environments. Their soft, moist integument has to meet the challenges of both habitats. While not possessing effective mechanisms to keep evaporatory water losses small, the skin makes up for them by osmotic reabsorption when in contact with liquid water. Here excessive osmotic swelling of the animal is prevented by a diencephalic control of the skin’s water permeability, a process supported by corresponding adjustments of kidney and urinary bladder function.

C.S. González

Papers

Changes in potential difference and short-circuit current produced by electrical stimulation in a nerve-skin preparation of the toad.

Further evidence for the release of noradrenalin under nerve stimulation and its effect on the potential difference in a toad nerve-skin preparation.