Learn More
Intra-axonal recordings were obtained from single afferent fibres of the posterior nerve in the isolated labyrinth of the frog (Rana esculenta). EPSPs and spike discharge were recorded both at rest and during rotatory stimulation of the canal. Electrical stimulation of either the distal end of the cut posterior nerve or of the central stumps of the(More)
L-glutamate (Glu) has at least two sites of action in the frog semicircular canal: the hair cell (presynaptic) and the primary afferent nerve fibres (postsynaptic). Glu's action on the hair cell results in an increased release of the natural transmitter which is responsible for a substantial increase in the frequency of firing in primary afferents. The(More)
The generator potential in sensory afferents of frog crista ampullaris was extracellularly recorded from the cut end of the posterior ampullary nerve by means of suction electrodes. A servocontrolled turntable allowed suitable rotatary stimulations. The analysis of the recorded generator potential revealed a different time course from that predicted on the(More)
The slow potentials and afferent discharge of impulses in frog semicircular canals have been studied at different endolymphatic and perilymphatic K+ concentrations. Results indicate that the presence of K ions in the bathing fluids is essential for maintaining the receptor function in crista ampullaris, although very low concentrations of this ion in the(More)
Features of action potentials and synaptic potentials as obtained by intracellular recordings from the sympathetic ganglion cells in the superior cervical ganglion of both the rat and the guinea-pig are described. Time-constant, imput resistance and capacitance of the ganglion cell membrane were also measured. Rheobasic currents and chronaxies are evaluated(More)
Stimulation of a post-ganglionic nerve trunk (internal carotid nerve) leads to synaptic activation of the majority of the sympathetic neurons in the superior cervical ganglion of the guinea-pig. Curarization of the ganglion and the section of the cervical sympathetic trunk eliminate any sign of synaptic activation in the ganglion cells produced by(More)
The role of various ions in stimuli conversion has been investigated in isolated frog semicircular canals, by replacing the endolymph with solutions deprived in turn of Na+, K+, Cl- and Ca++. Mechanical and electrical stimuli were employed and slow ampullar and nerve potentials were recorded, together with the afferent discharge of impulses in the eighth(More)