The effect of temperature on the refractory period in nerve fibres is of the same magnitude as its effect on the duration of the action potential (Tasaki, 1949) or as the effect of temperature on the duration of the falling phase of the spike (Adrian, 1921). Temperature coefficients (Q10) as high as 4 have been calculated for the refractory period in single fibres of the frog by Schoepfle & Erl...

The anatomy and histology of the unpaired ventral nerves are described from lightand electron-microscopical studies. Seven unpaired nerves arise from the median dorsal surface of the ventral ganglionic nerve-mass, and terminate in abdominal segments 2 to 8 respectively. Each unpaired nerve bifurcates, sending a lateral nerve to both sides of its respective segment. Subsequently the lateral nerv...

Phosphate glass fibres with composition 50P(2)O(5)-30CaO-9Na(2)O-3SiO(2)-3MgO-(5-x)K(2)O-xTiO(2)mol.% (x=0, 2.5, 5, respectively coded as TiPS(0), TiPS(2.5) and TiPS(5)) were drawn following the preform drawing approach. A 20-day solubility test in bi-distilled water was carried out on glass fibres with different compositions and diameters ranging between 25 and 82 μm. The results show that the...

The changes in the axon and growth cone numbers in the optic nerve of the freshwater turtle Mauremys leprosa were studied by electron microscopy from the embryonic day 14 (E14) to E80, when the animals normally hatch, and from the first postnatal day (P0) to adulthood (5 years on). At E16, the first axons appeared in the optic nerve and were added slowly until E21. From E21, the fibre number in...

Experiments using electrical stimulation of different groups of muscle afferent nerve fibres have shown that most of the known medullated fibres in muscle nerves are involved in reflexly stimulatihg ventilation (Bessou et al. 1959, Koizumi et al. 1961, Senapati 1966). Investigations using natural stimulation of muscle receptors and pmsive limb movements (Kao et al. 1963, Senapati 1966, Kalia et...

T HE experiments described in this paper were undertaken with the idea of ascertaining the quantitative relation between the strength of the external stimulus applied to the nerve, and the strength of the resulting nerve impulse. The nature of the nerve impulse is as yet undetermined. We may recognize its presence in the nerve, however, in two ways : by the change in the electrical condition of...

Laryngeal nerves contain the fibres that control the laryngeal function. The studies carried out on the rat with the purpose of having a better knowledge of the functional components and the real origin of the fibres conveyed by the recurrent laryngeal nerve (RLN) are few and in disagreement. No one of such papers were developed using biotinylated dextrane amines (BDA), a powerful tool for trac...

The role of the autonomic nerve on the gastric motility of the domestic fowl has been investigated by Nolf (1), Ihnen (2) and Hassan (3). Nolf has reported that both excitatory and inhibitory fibres are included in the vagus and also in the sympathetic nerve to the proventriculus and gizzard. However, there is little detailed study on the mechanism which causes excitatory and inhibitory respons...

VIP-, substance P- and met-enkephalin-containing innervation of the human gastroduodenal mucosa and Brunner's glands was studied by immunocytochemistry on whole mount tissue preparations. A dense VIP-containing nerve supply was found around fundic and pyloric glands, while the few and scattered substance P-immunoreactive fibres tended to run across the full thickness of the gastric mucosa. In t...

Morphological methods were used to examine injury-induced growth of peripheral and central axons of nociceptive mechanosensory neurones in the ventrocaudal (VC) clusters of the pleural ganglia of Aplysia californica. Pedal nerve crush transected all axons in the nerve while leaving the overlying sheath largely intact. Immunohistochemical staining was performed with an antibody to a sensory-neur...