Long-term feeding on powdered food causes hyperglycemia and signs of systemic illness in mice.

Aims: Dietary habits are crucial factors affecting metabolic homeostasis. However, few animal experiments have addressed the effects of long-term feeding with soft food on parameters reflecting systemic health.

Main Methods: Using mice, we compared the effects of short (3 days) and long (17 weeks from weaning) feeding periods between powdered food and normal pellet food on the levels of blood glucose, serum levels of insulin, catecholamines, and corticosterone, blood pressure, and/or social interaction behaviors.

Roles played by histamine in strenuous or prolonged masseter muscle activity in mice.

Bruxism and/or clenching, resulting in fatigue or dysfunction of masseter muscles (MM), may cause temporomandibular disorders. Functional support of the microcirculation is critical for prolonged muscle activity. Histamine is a regulator of the microcirculation and is supplied by release from its stores and/or by de novo production via the induction of histidine decarboxylase (HDC).

Influence of a long-term powdered diet on the social interaction test and dopaminergic systems in mice.

It is well known that the characteristics of mastication are important for the maintenance of our physical well-being. In this study, to assess the importance of the effects of food hardness during mastication, we investigated whether a long-term powdered diet might cause changes in emotional behavior tests, including spontaneous locomotor activity and social interaction (SI) tests, and the dopaminergic system of the frontal cortex and hippocampus in mice. Mice fed a powdered diet for 17 weeks from weaning were compared with mice fed a standard diet (control).

Roles of histamine in exercise-induced fatigue: favouring endurance and protecting against exhaustion.

Exercise necessitates a large supply of O(2) and nutrients and rapid removal of CO(2) and waste products. Histamine is a regulator of the microcirculation (which performs these exchanges), suggesting a possible involvement of histamine in exercise. Histamine is released from either mast cells or non-mast cells.

p-Hydroxyamphetamine causes prepulse inhibition disruption in mice: contribution of serotonin neurotransmission.

p-Hydroxyamphetamine (p-OHA) has been shown to have a number of pharmacological actions, including causing abnormal behaviors such as increased locomotor activity and head-twitch response in rodents. We have recently reported that intracerebroventricular (i.c.