PT  - JOURNAL ARTICLE
AU  - Céline Périer
AU  - Léon Tremblay
AU  - Jean Féger
AU  - Etienne C. Hirsch
TI  - Behavioral Consequences of Bicuculline Injection in the Subthalamic Nucleus and the Zona Incerta in Rat
AID  - 10.1523/JNEUROSCI.22-19-08711.2002
DP  - 2002 Oct 01
TA  - The Journal of Neuroscience
PG  - 8711--8719
VI  - 22
IP  - 19
4099  - http://www.jneurosci.org/content/22/19/8711.short
4100  - http://www.jneurosci.org/content/22/19/8711.full
SO  - J. Neurosci.2002 Oct 01; 22
AB  - The subthalamic nucleus (STN) plays a crucial role in basal ganglia functions and has been shown to be hyperactive in parkinsonian syndromes. The zona incerta (ZI), located dorsally to the STN, is also reported to be overactive after nigrostriatal denervation. In this study, we examined the behavioral consequences of an increased activity of the STN or the ZI in awake, freely moving rats. Unilateral microinjections of a GABAA receptor antagonist (bicuculline; 25, 50, and 100 μg/μl) were performed in the STN or in the ZI of rats, and locomotor activity, spontaneous behaviors, and the occurrence of abnormal movements were quantified. Microinjection of bicuculline (50 and 100 μg/μl) into the STN did not modify spontaneous locomotor activity, whereas it induced an increase in locomotion when injected into the ZI. Furthermore, when injected into the STN or ZI, these same doses of bicuculline produced changes in spontaneous behaviors (sniffing and grooming decreased whereas chewing and rearing increased) and the appearance of abnormal movements directed contralaterally to the injection side. Application of a lower dose of bicuculline (25 ng/μl) in the STN or ZI did not modify behavior. This study suggests that the subthalamic region including the ZI, and not the STN per se, might be involved in the induction of abnormal movements. In addition, these data suggest that the hyperactivity of neurons in this region may have different consequences in the normal state and in the pathological state.