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Biomedical subjects

A Romaniuk

Publications and source records attributed to A Romaniuk.

54 records · Page 3Linked to original sources
PubMed1979

Adrenergic modulation of the hypothalamic cholinergic mechanism in the control of emotional-defensive behavior in the cat.

Effects of drugs influencing the activity of the hypothalamic noradrenergic system on the carbachol-induced emotional-defensive response were investigated. Intrahypothalamic injections of noradrenalin, amphetamine and reserpine did not produce any changes in cats' behavior. Injections of carbachol into the same hypothalamic loci, following the injections of noradrenalin, amphetamine or reserpine evoked all the characteristic symptoms of emotional-defensive behavior. However, a strong decrease in the number of growls and the duration of growling was observed when reserpine injections preceded the injections of carbachol into the same hypothalamic areas. Adrenergic alpha and beta agonists (methoxamine and isoprenaline) as well as antagonists (phentolamine and oxprenolol) when injected alone had no influence on the cats' behavior. Their effect on vocal responses evoked by subsequent injections of carbachol was not statistically significant. Results show that emotional-defensive behavior cannot be triggered by an activation of the hypothalamic noradrenergic system. However, emotional defensive behavior induced by cholinergic stimulation of the hypothalamus may be modified by changes in the activity of the hypothalamic noradrenergic system.

Animals↗
PubMed1977

Midbrain interaction with the hypothalamus in expression of aggressive behavior in cats.

The effects of injections of M- and N-cholinergic blocking agents into the antero-medial hypothalamus (HM) and the midbrain central gray (GC) on the aggressive behavior of cats, evoked by microinjections of carbachol into those areas, were investigated in chronic experiments. The influence of pharmacological suppression of the M-cholinergic system in HM on the carbachol-induced aggression response from GC and vice versa was also studied. In the experiments a quantitative method was applied for measuring the specific vocalization - growling, which is a characteristic of aggressive behavior. In the HM and GC areas of the cat the N- and the M-cholinergic systems participated in the control of aggressive behavior, but the M-component dominated in the process. The suppression of M-cholinergic system in GC prevented the appearance of aggressive behavior evoked by injections of carbachol into HM, and the M-cholinergic blockade in HM reduced (by 90 percent) the aggression response evoked by the injections of carbachol into GC. It is concluded that a concurrent action of the hypothalamic and the midbrain cholinergic systems is necessary for the appearance of a fully expressed aggressive behavior. The hypothalamus and the midbrain are probably links of the same functional circuit, and that the control of aggressive behavior is based on a circulatory action between these structures.

Aggression↗
PubMed1974

Neurochemical bases of defensive behavior in animals.

This paper presents a literature review and the author's own investigations devoted to identifying the morphological organization of different subcortical structures and neurochemical processes involved in the (regulation of defensive behavior. The effects of intrahypothalamic injections of two cholinomimetic substances, carbachol and d-tubocurarine, on rage and fear reactions were explored. Also the investigations were carried out with intrahypothalamic injections of anticholinergic substances, atropine and betamon or hexamethonium, which block selectively muscarinic and nicotinic receptors. The results indicate that carbachol injected into the hypothalamus after blocking the muscarinic receptors with atropine fails to elicit any defensive response; whereas carbachol injection administrated after nicotinic receptors had been blocked by betamon or hexamethonium induces full aggressive behavior. This indicated that carbachol acts, on the hypothalamic level, through the muscarinic receptors. The mechanism of d-tubocurarine action seems to be more complex because this compound induces fear response after either the muscarinic or the nicotinic receptors have been blocked. A possible mechanism based on chemically differentiated neuronal circuits at the hypothalamic level for two different defensive drives, fear and rage, is presented.

Aggression↗
PubMedDate not supplied

Comparison of defensive behavior evoked by chemical and electrical stimulation of the hypothalamus in cats.

Comparison of defensive behavior evoked by chemical anf electrical stimulation of the hypothalamus in cats. Acta Physiol. Pol. 1975, 26 (1) 23--31. An injection of 5 mug of carbachol, as well as electrostimulation of the same hypothalamic area evoked in cats the same type of defensive behavior -- rage reaction. Experiments with carbachol injection and electrostimulation after blockade of the hypothalamic muscarinic receptors (10 mug of atropine) indicate that rage reaction is evoked in a different way by the two methods. Controversial data regarding localization of the hypothalamic "centres" responsible for particular type of defensive reactions are discussed.

Animals↗
PubMedDate not supplied

The correlation between hypothalamic and midbrain biogenic amine content and the intensity of the emotional-defensive arousal in cats.

Changes in levels of noradrenaline (NA), dopamine (DA), serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in the medial hypothalamus and the midbrain central grey matter were determined and correlated with various levels of an emotional-defensive arousal in cats, evoked by an intrahypothalamic injection of carbachol. At the initial stage of excitation, 3 min after the injection of carbachol, the levels of NA, DA, and 5-HIAA in the medial hypothalamus increased, whereas in the central grey matter only the 5-HIAA level was elevated. During the maximum excitation (when the vocalization attained the peak level) the level of amines and 5-HIAA decreased in the medial hypothalamus; in the central grey matter only the levels of 5-HT and 5-HIAA declined. In the final phase of response, 5 min after the disappearance of vocalization, the 5-HT level in both structures increased. These results confirm the notion that the noradrenergic, dopaminergic and serotonergic systems participate in the central regulation of the emotional-defensive behavior, and show that the hypothalamus and midbrain play different roles in this regulation. The results also indicate that neurochemical mechanisms are similar in different types of emotional-defensive behavior. It seems that catecholaminergic systems play a stimulating role, while the serotonergic system inhibits the carbachol-induced defensive response.

Animals↗
PubMedDate not supplied

The influence of injection of 5,6-dihydroxytryptamine to the dorsal raphe nucleus on carbachol-induced defensive behavior and regional brain amine content in the cat.

The 5,6-dihydroxytryptamine-induced lesions of serotonergic neurons in the dorsal raphe nucleus of the cat resulted in an increase in the carbachol-induced growling response, a decrease in the concentrations of noradrenaline, serotonin and 5-hydroxyindoleacetic acid in the hypothalamus, midbrain and amygdala, and an increase in the hypothalamic dopamine level. Those changes were observed 6, but not 23, days after the lesion. The results suggest a close correlation between the state of the emotional-defensive arousal and neurochemical changes in the "emotional regions" of the brain. The role of the reduced activity of the serotonergic system in augmenting the emotional-defensive behavior was discussed.

5,6-Dihydroxytryptamine↗
PubMedDate not supplied

Increased expression of class II major histocompatibility complex antigens in untreated and cyclosporine-treated rat lung allografts.

Expression of class II antigens was investigated in the normal rat lung and in lung allografts during acute rejection and after cyclosporine treatment. Therefore cryostat sections were stained with an immunoperoxidase technique that used anti-class II antigen monoclonal antibodies. In normal lungs only cells of the lymphoid tissue expressed class II antigens. During acute rejection, class II antigens were expressed by infiltrating recipient lymphocytes and were also induced on the graft's bronchial epithelium. After cyclosporine treatment, signs of rejection in the lung were restricted to the bronchial epithelium, again expressing class II antigens. These results suggest that the class II antigen positivity of bronchial epithelium may be used as a specific index for pulmonary rejection when infection as an inducing factor can be excluded. Furthermore, the epithelium, once it has become class II antigen positive, is likely to be a target for acute or low-grade rejection, resulting in the development of bronchiolitis obliterans.

Animals↗
PubMedDate not supplied

An analysis of the carbachol-induced emotional-defensive response in cats: dependence of the response on different solvents of carbachol.

The effect of intrahypothalamic injections of carbachol (25.1 nmole into each hemisphere) dissolved in three different solvents (artificial cerebrospinal fluid, physiological saline and bidistilled water) was investigated. The purpose of this study was to find out whether the qualitative and/or quantitative character of the carbachol-induced emotional-defensive behavior depended on the sort of the solvent used. The analysis was performed on the basis of behavioral and electroencephalographic changes. Apart from routine EEG recordings, integrated measurements of the amplitude of alpha, beta, delta, and theta waves recorded rom the posterior hypothalamus, the midbrain central gray matter and from the dorsal hippocampus were performed as well as quantitative measurements of the characteristic growling. Intrahypothalamic injections of carbachol, independently of the solvent used, evoked similar vegetative, behavioral and electroencephalographic changes (in the routine recordings). The number of growls and the total duration of growling did not differ significantly either. Some statistically significant changes were found in the integrated amplitudes of EEG waves. They concerned, however, only alpha and theta rhythms and appeared in the midbrain central gray matter. Moreover, they did not affect the time course and the quantitative and qualitative features of the evoked emotional-defensive response. All used solvents are equivalent and may be applied interchangeably in experiments of this type.

Animals↗