Balance control and posture differences in the anxious BALB/cByJ mice compared to the non anxious C57BL/6J mice

A relation between anxiety disorders and balance control dysfunctions has b een observed in many studies in humans. A mismatch in the integration of se nsory inputs could trigger these disturbances. Very few experimental animal procedures have been designed to study the functional link between anxiety and balance control. A task was therefore developed, challenging the visua l, vestibular and somesthesic sensory systems in mice. The test, called the 'rotating beam', gave an accurate assessment of balance control and the po sture, using sensitive measures (number of falls and imbalances, position o f tail and trunk). Striking differences were observed between the two inbre d strains of mice known to have radically different anxiety-related behavio ur. The highly anxious strain, BALB/cByJ, performed poorly compared to the non anxious strain, C57BL/6J. Balance control and postural abilities of anx ious mice were improved by acute anxiolytic diazepam treatment. Lower behav ioural performance level was registered in non anxious mice given anxiogeni c beta -CCM treatment. The findings account for a strong relationship betwe en anxiety and balance control in mice. Finally, the highly sensitive proce dure proved to be well suited to the study of functional links between anxi ety and sensorimotor processes. (C) 2000 Elsevier Science B.V. All rights r eserved.