Differentially altered cerebral metabolism in ischemic rats by alpha2-adrenoceptor blockade and its relation to improved limb-placing reactions.

Abstract

The selective alpha2-adrenoreceptor antagonist, atipamezole, improves behavioural performance of rats subjected to focal cerebral ischemia. The aim of the present study was to investigate whether the facilitatory effect of atipamezole on behaviour is related to altered neuronal activity in specific brain areas. The right middle cerebral artery of rats was occluded for 120 min using the intraluminal filament method. Starting on day 2 after induction of ischemia, atipamezole (1mg/kg, s.c.) or 0.9% NaCl was administered to ischemic or sham-operated rats once a day 30 min before the limb-placing test. [14C]Deoxyglucose ([14C]DG) uptake was used to measure neuronal activity 30 min after atipamezole or 0.9% NaCl administration on day 6 after ischemia. Ischemia induced a significant decrease in [14C]DG uptake in several cortical areas ipsilateral and contralateral to the lesion, in the ipsilateral thalamus, and bilaterally in the cerebellum and spinal cord. Administration of atipamezole normalised [14C]DG uptake particularly in the cerebellum and spinal cord both in sham-operated and ischemic rats and to a lesser extent in the thalamus in sham-operated rats. The pattern of altered cerebral [14C]DG uptake following alpha2-adrenoceptor blockade suggests that plasticity in the cerebellum and spinal cord contributes to the improved performance of ischemic rats in tests assessing tactile/proprioceptive limb-placing reactions.

• Authors: Alexandra Barbelivien, Jukka Jolkkonen, Edita Rutkauskaite, Jouri Sirviö, Juhani Sivenius
• Journal: Neuropharmacology (Neuropharmacology) Vol. 42 Issue 1 Pg. 117-26 (Jan 2002) ISSN: 0028-3908 [Print] England
• PMID: 11750921 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adrenergic alpha-2 Receptor Antagonists
• Adrenergic alpha-Antagonists
• Antimetabolites
• Imidazoles
• atipamezole
• Deoxyglucose

Topics

• Adrenergic alpha-2 Receptor Antagonists
• Adrenergic alpha-Antagonists (pharmacology)
• Animals
• Antimetabolites (pharmacology)
• Autoradiography
• Behavior, Animal (drug effects)
• Brain Chemistry (drug effects)
• Cerebral Infarction (pathology)
• Deoxyglucose (metabolism)
• Imidazoles (pharmacology)
• Ischemic Attack, Transient (metabolism, pathology)
• Male
• Movement (drug effects)
• Rats
• Rats, Wistar