دورية أكاديمية
Microinjections of α1 and α2 noradrenergic substances in the cerebellar vermis of decerebrate cats affect the gain of the vestibulospinal reflexes
| العنوان: | Microinjections of α1 and α2 noradrenergic substances in the cerebellar vermis of decerebrate cats affect the gain of the vestibulospinal reflexes |
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| المؤلفون: | ANDRE, P., D'ASCANIO, P., PIRODDA, A., POMPEIANO, O. |
| المساهمون: | Andre, P., D'Ascanio, P., Pirodda, A., Pompeiano, O. |
| بيانات النشر: | DIP Fisiologia Biochimica:via S Zeno 31, 56127 Pisa Italy:EMAIL: arch.ital.biol@dfb.unipi.it, Fax: 011 39 050552183 |
| سنة النشر: | 1991 |
| المجموعة: | Università degli Studi di Siena: USiena air |
| مصطلحات موضوعية: | body posture, cerebellar cortex, labyrinth, vestibular nerve, reflex, microinjections, adrenergic alpha-agonists, adrenergic alpha-antagonists, cats, decerebrate state |
| الوصف: | 1. In addition to mossy and climbing fibers, the Purkinje (P)-cells of the cerebellar cortex receive noradrenergic (NA) afferents which originate mainly from the locus coeruleus. Since these fibers impinge also on the vermal cortex of the cerebellar anterior lobe, which receives a labyrinth input and projects to the lateral vestibular nucleus, experiments were performed in precollicular decerebrate cats to find out whether unilateral injection of alpha-adrenergic substances into the vermal cortex of the cerebellar anterior lobe exerted some influence on posture as well as on the dynamic characteristics of vestibulospinal (VS) reflexes evaluated by recording the multiunit EMG responses of the forelimb extensor triceps brachii of both sides to roll tilt of the animal at 0.15 Hz, +/- 10 degrees. 2. Unilateral injection into the vermal cortex of the culmen of the alpha 1-adrenergic agonist metoxamine or the alpha 2-adrenergic agonist clonidine (0.25 microliters at the concentration of 4 micrograms/microliters of saline) produced a postural asymmetry, characterized mainly by a slight decrease of the extensor tonus in the ipsilateral forelimb and an increased tonus in the contralateral forelimb. The same substances significantly increased the gain (imp./sec/deg) of the first harmonic component of the EMG responses of the ipsilateral and the contralateral triceps brachii to animal tilt. The crossed effects were more prominent for the alpha 2- than for the alpha 1-agonist. However, no significant changes in the phase angle of the responses were observed in both instances. The effects described above occurred within 5-10 min after the injection, reached the peak values after 15-20 min, and disappeared within 2 hours. 3. The postural and reflex changes described above were not due to irritative events following the injection, since they were not observed in control experiments after injection of 0.25 microliter of saline into the same corticocerebellar area prior to the administration of the alpha 1- or the alpha ... |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | STAMPA |
| اللغة: | Italian |
| العلاقة: | info:eu-repo/semantics/altIdentifier/pmid/1678594; info:eu-repo/semantics/altIdentifier/wos/WOS:A1991FC67700004; volume:129; issue:2; firstpage:113; lastpage:160; numberofpages:48; journal:ARCHIVES ITALIENNES DE BIOLOGIE; http://hdl.handle.net/11365/417396Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0026133664; http://architalbiol.org/aib/article/view/129113Test |
| الإتاحة: | http://hdl.handle.net/11365/417396Test http://architalbiol.org/aib/article/view/129113Test |
| رقم الانضمام: | edsbas.D4AEC7C3 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |