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Biomedical subjects

K Schubert

Publications and source records attributed to K Schubert.

162 records · Page 9Linked to original sources

Neurotransmitters regulating feline aggressive behavior.

The experiments described in this review reveal that the expression and modulation of aggressive responses in the cat are organized by two distinct sets of pathways. One set of pathways is associated with the elicitation of a specific form of attack behavior. It includes the medial hypothalamus and its projections to the PAG for the expression of defensive rage behavior and the lateral hypothalamus and its descending projections for the expression of predatory attack behavior. The primary focus of the present review is upon the analysis of defensive rage behavior. It was demonstrated that the pathway from the medial hypothalamus to the PAG, which appears to be essential for elicitation of defensive rage, is powerfully excitatory and utilizes excitatory amino acids that act upon NMDA receptors within the PAG. The other pathways examined in this review arise from different nuclei of the amygdala and are modulatory in nature. Here, two facilitatory systems have been identified. The first involves a projection system from the basal complex of amygdala that projects directly to the PAG. Its excitatory effects are manifest through excitatory amino acids that act upon NMDA receptors within the PAG. The second facilitatory pathway arises from the medial nucleus of the amygdala. However, its projection system is directed to the medial hypothalamus rather than the PAG. Its neurotransmitter appears to be substance P that acts upon NK1 receptors within the medial hypothalamus (see Figure 10). It has yet to be determined whether substance P acts upon any of the other neurokinin receptor subtypes. It should also be pointed out that the substance P pathway from the medial amygdala to the medial hypothalamus functions to suppress predatory attack behavior elicited from the lateral hypothalamus. In this network, it is likely that the modulatory effects of the medial amygdala require the presence of a second, inhibitory pathway from the medial hypothalamus that innervates the lateral hypothalamus. At the present time, the neurochemical nature of this second pathway remains unknown, although it is suggested that such neurons may be GABAergic. One major inhibitory pathway was also identified. It arises principally from the central nucleus of the amygdala and projects to the PAG. Its powerful suppressive effects upon PAG elicited defensive rage behavior are mediated through opioid peptides that act upon mu receptors within the PAG. While the present series of studies have begun to define the structural and functional nature of the neural systems that regulate aggressive behavior, our understanding of the overall mechanisms regulating different forms of aggressive behavior remains incomplete.(ABSTRACT TRUNCATED AT 400 WORDS)

Aggression↗

[Interferonogenicity of the bacterial lysates in human and murine cell cultures].

The antibacterial JRS vaccine was found to be capable of inducing interferon production in human peripheral blood leukocytes and mouse bone marrow cells. The vaccine induced no interferon in L-929 cells or human diploid M-19 cells. Interferon appeared in the culture fluid within 4-6 hours after induction and reached the maximum levels in 18-24 hours. One-hour contact of the vaccine with leukocytes was sufficient for interferon induction. The interferon generated in human blood leukocytes was partially stable at pH 2.2; heating at 56 degrees C for 30 min reduced its activity 4-fold; antiserum to alpha-interferon inhibited it.

Animals↗

[Fitness and stress tolerance of myocardial infarct rehabilitation in patients in relation to age].

Results on fitness and exercise tolerance of patients undergoing rehabilitation after myocardial infarction are shown in dependence on age. The fitness data of the patients recovering from myocardial infarction can be classified with the lower reference region of untrained normal populations and are subject to the same regularities in the ageing process. For sports therapy a versatile endurance training with average blood lactate concentrations of 2.5-3.5 mmol/l is recommended. The greater strain on the aerobic-anaerobic metabolism in older infarction patients during sports therapy emphasizes the necessity of the age-specific design of exercises.

Exercise Test↗