Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Glutamate in the basal ganglia has a crucial role in the regulation of motor behaviour. Until now studies addressing the function of glutamate acting via ionotropic receptors predominate. Glutamate however also activates second messenger coupled receptors, the metabotropic glutamate receptors (mGluRs) of which eight subtypes are cloned and classified in three group so far. Recently we had shown that the mGluRs have important roles for motor behaviour as well, as i.c.v. infusions of the broadband group I/II mGluR agonist 1S,3R-ACPD dose-dependently induced catalepsy and depressed locomotor activity. Group II receptors at least partially mediate this effect, since the group II agonist L-CCG I had qualitatively similar effects. The question which is the contribution of group I mGluRs was not yet directly addressed by agonists, because activation of group I, opposite to group II, mGluRs induces neurodegeneration. For this, we studied the effects of (S)-4C3H-PG, activating group II mGluRs while blocking group I mGluRs. Effects of (S)-4C3H-PG on motor behaviour were tested alone and combined with administrations of dopamine D1 and D2 receptor antagonists. We infused (S)-4C3H-PG locally into the striatum of rats, using chronically implanted guide cannulas. Locomotor and sniffing behaviour was analysed in an open field with holeboard and an experimental chamber, respectively. The detailed data presented are discussed in respect to their possible implications on human basal ganglia disorders. Supported by the DFG SFB 307/A4.

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Poster Number PAkronthaler0569
Keywords: metabotropic, glutamate, basal ganglia, behavior, parkinson