Hyperpolarizing responses to stretch in sensory neurones innervating leech body wall muscle.

摘要: 1. The membrane properties, morphology and physiological responses of peripherally located sensory neurones that innervate body wall muscle the leech Hirudo medicinalis have been investigated using intracellular recording dye injection techniques. 2. peripheral their dendrites were visualized directly in whole mounts by horseradish peroxidase or Lucifer Yellow. They lie along course segmental nerves between layers longitudinal oblique within sheath nerve. a distinctive with two expanded, fan-shaped arranged series separated cell 300 micron long cylindrical process. Both are associated ventral but separate bands fibres. axons project into nerve cord arborize ipsilateral half ganglion. No processes extend across mid-line ganglion enter connectives to neighbouring ganglia. 3. 'Resting' potentials recorded from axon as it entered ranged -30 -70 mV. transmembrane potential depended on amount which was stretched: most hyperpolarized values stretched preparations. Although can generate overshooting action these not actively propagated CNS. Rather, imposed voltage changes spread decrementally axon. Input resistances measured 14 26 M omega. space constant, estimated hyperpolarizing current injected body, 2.4 mm. 4. response change length near its terminal arborization is graded DC signal: thus relay information CNS synapses analogue form. Spiking activity extracellularly anterior root stretch due activation touch mechanosensory cells skin. 5. Unlike receptors innervating skeletal vertebrates arthropods, respond maintained release depolarization.(ABSTRACT TRUNCATED AT 400 WORDS)