Behavioural characterization and amounts of brain monoamines and their metabolites in mice lacking histamine H1 receptors
Yanai K, Son LZ, Endou M, Sakurai E, Nakagawasai O,
Tadano T, Kisara K, Inoue I, Watanabe T, Watanabe T
Department of Pharmacology I,
Tohoku University School of Medicine, Sendai, Japan.
Neuroscience 1998 Nov; 87(2): 479-87


Behavioural assessments were made of mutant mice lacking histamine H1 receptors to reveal the function of H1 receptors in the behaviour of mice. Exploratory behaviour of mice in a new environment was examined to discover whether the absence of H1 receptors in mice affects actions relating to their emotions. The H1 receptor-deficient mice showed a significant decrease in ambulation in an open field and on an activity wheel. Cognitive functions and anxiety were examined using passive avoidance response test and the elevated plus-maze test, respectively. The passive avoidance test did not show any change in latency. The elevated plus-maze test revealed that the transfer latency of the mutant mice was significantly prolonged, indicating that H1 receptors are partly associated with the control of anxiety. Aggressive behaviour was examined by a resident-intruder aggression test. When confronted with an intruder, the mutant mice attacked the intruder significantly slower and less frequently than did wild-type mice after a six-month isolation period. A formalin test and a forced swimming test were used to evaluate the nociceptive response and depressive or despairing state, respectively, of both groups. The mutant mice showed a significant decrease of nociceptive response in the late phase without affecting the early phase. There was no significant difference in the forced swimming test between the two groups. The brain content of monoamines and their metabolites was measured in the H1 receptor null and wild-type mice. The turnover rate of 5-hydroxytryptamine defined by the ratio of 5-hydroxyindoleacetic acid and 5-hydroxytryptamine was significantly increased in the cerebral cortex and hippocampus of H1 receptor null mice. These results support the previous pharmacological findings that histamine modulates various neurophysiological functions such as locomotor activity, emotion, memory and learning, nociception and aggressive behaviour through H1 receptors.
Sleep deprivation
Retarded depression
Diphenhydramine (Benadryl)
Types of depression and mood-disorder
Antihistamines, cognition and performance
Antihistamines: dimenhydrinate (Dramamine)
Diphenhydramine (Benadryl) and venlafaxine
Histamine H3 receptor antagonist/inverse agonists

and further reading

Future Opioids
BLTC Research
Utopian Surgery?
The Abolitionist Project
The Hedonistic Imperative
The Reproductive Revolution
Critique of Huxley's Brave New World

The Good Drug Guide
The Good Drug Guide

The Responsible Parent's Guide
To Healthy Mood Boosters For All The Family