Biomedical subjects

G Hellekant

Publications and source records attributed to G Hellekant.

At least 55 records · Page 3Linked to original sources

PubMed1977

Vasodilator fibres to the tongue in the chorda tympani proper nerve.

Electrical stimulation of the chorda tympani proper nerve (CT) causes vasodilatation in the constant-flow perfused tongue. It has been suggested, as an explanation for this, that the vasodilatation is the result of antidromic impulses in sensory fibres of the CT. However, after degeneration of the efferent fibres in CT in the rat it was found that electrical stimulation of the CT caused no vasodilatation. Since, by all criteria available, the sensory fibres remained, the result indicates that antidromic impulses could not be the cause of the vasodiltation observed in tongues with intact nerve supply. Further, since there are no glands in the part of the tongue innervated by the CT and the circulation of the large salivary glands is separate from the tongue in the rat, it is concluded that the vasodilatation was not a secondary effect of glandular activity, but was caused by vasodilator fibres in the CT.

Animals↗

PubMed1977

[Behavioural and electrophysiological experiments on the sense of taste in Saguinus midas tamarin (Callitrichidae) (author's transl)].

The activity in the gustatory nerve from the anterior part of the tongue, the chorda tympani proper nerve, has been recorded during stimulation of the tongue of a New World monkey, Saguinus midas tamarin. A series of 0.3 M sugars and 0.07 M NaCl, 0.07 M sucrose, 0.004 M acetic acid and 0.00005 M quinine hydrochloride were used as taste stimuli. The concentrations of the last four stimuli were the same as those earlier found to be the lowest concentrations at which this monkey in behavioural experiments discriminates between them and water. The records showed that these threshold concentrations all elicited a neural response. Further, the neural activities during stimulation with the series of 0.3 M sugars were recorded. Using the amplitudes of the responses as a measure, the order between them was found to be fructose greater than glucose greater than lactose greater than arabinose greater than sucrose = galactose greater than raffinose. This order was discussed and related with the order found in behavioural experiments. With both methods, fructose seemed to be the strongest stimulus, but then the order among the sugars differed.

Acetates↗

PubMed1976

On the effects of gymnemic acid in the hamster and rat.

The gustatory activity of the chorda tympani proper nerve has been recorded before and after the application of gymnemic acid to the tongue of hamster and rat. Concentrations of pure gymnemic acid ranging from 1 mg/ml to 10 mg/ml have been used. In the hamster gymnemic acid suppressed the response to solutions of sucrose especially, but it also caused, at higher concentrations, a general suppression of the tast response. The depression caused in the response to sucrose was directly related to the strength of the gymnemic acid and inversely to that of the sucrose solution. In the rat a suppression of the response to saccharin was obtained but no suppression of the taste response to sucrose by gymnemic acid was observed.

Action Potentials↗

PubMed1976

Gustatory effects of miraculin, monellin and thaumatin in the Saguinus midas tamarin monkey studied with electrophysiological and behavioural techniques.

A comparative electrophysiological and behavioural study has been made in 17 closely related monkeys of the new world species, Saguinus midas tamarin. The electrical activity in the chorda tympani proper nerve of two of the monkeys was recorded during the application to the tongues of 0.02% monellin and thaumatin, 0.5% miraculin and stimuli representing the four taste qualities. It was observed that monellin and thaumatin gave no or little response and that miraculin enhanced the response to the sour stimulus, but not that to any other taste quality. Behavioural studies were then made with a two-bottle preference test in 15 monkeys. It was found that the animals did not discriminate or discriminated poorly between water and thaumatin or monellin. After miraculin they changed their strong rejection of 0.02 M citric acid, in a choice between water and acid, into a strong preference for the acid. These results show a close relation between the electrophysiological and the behavioural data.

Action Potentials↗

PubMed1976

The blood circulation of the tongue.

This article describes the gross anatomy of the vessels which supply the mammalian tongue. It shows that there is a rich vascular supply. Available data indicate that the lingual papillae are supplied with a true capillary circulation, which is more abundant in the papillae containing taste buds. The vessels of the tongue are innervated by adrenergic sympathetic vasconstrictor fibers and it is also very likely that a cholinergic parasympathetic vasodilator influence exists.

Animals↗

PubMed1975

Depression of taste responses by local or intravascular administration of salicylates in the rat.

The effects of aspirin and sodium salicylate on the taste response in the chorda tympani proper nerve have been studied during stimulation of the taste receptors in rats with salty, sweet, sour and bitter-tasting solutions. Three methods of administering the drugs were used: locally on the tongue, intravenously into one femoral vein and intraarterially close to the branching of the lingual artery. It was observed that salicylates, given in any of these three ways, depressed the response to taste stimuli. This is discussed in relation to present views on the action of salicylates.

Administration, Topical↗

PubMed1974