title: Fastigial influences on postural tonus as studied by kainate lesions and by local infusion of GABAergic drugs in the rat.
abstract: Localized lesions with kainic acid (KA) and local infusion of GABAergic drugs were used to study the role of the nucleus fastigii (NF) in postural tonus. Unilateral axon-sparing KA lesions of NF resulted in ipsilateral limb extensor atonia and contralateral limb extensor hypertonus and abduction. This effect lasted for 3-8 days depending on the dose of KA. Lesions of sites adjacent to the NF failed to produce postural asymmetries. Local infusion of the GABA agonist muscimol (10-50 ng) in the NF produced a reversible postural asymmetry fenomenologically similar to that produced by KA lesions of NF. Infusion of agents blocking GABAergic transmission in the NF (bicuculline, picrotoxin) resulted in a postural asymmetry of inverted laterality in respect to that produced by muscimol. Bilateral KA lesions of NF or bilateral infusion of muscimol resulted in bilateral hyperextension-abduction of the limbs. Infusion of GABAergic drugs in areas adjacent to the NF failed to produce postural changes. The results are interpreted to indicate that the NF exerts a crossed inhibitory and a direct excitatory influence on limb postural tonus.
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000633:toxicity; D002529:Cerebellar Nuclei / Q000187:drug effects / Q000502:physiology*; D003975:Diazepam / Q000494:pharmacology; D007839:Functional Laterality; D007608:Kainic Acid / Q000633:toxicity*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009129:Muscle Tonus / Q000187:drug effects*; D010852:Picrotoxin / Q000633:toxicity; D011187:Posture; D011759:Pyrrolidines / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D013238:Stereotaxic Techniques; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
chemical_list: D001640:Bicuculline; D003975:Diazepam; D007608:Kainic Acid; D010852:Picrotoxin; D011759:Pyrrolidines; D005680:gamma-Aminobutyric Acid