Role of the thalamic reticular nucleus in the generation of rhythmic thalamo-cortical activities subserving spike and waves.
The role of the reticular thalamic nucleus (RTN) in pacing rhythmic cortical activities subserving spike-waves (SW) discharges has been investigated in rats. Intracellular recordings from thalamic slices in vitro demonstrated that RTN neurons from control animals possess a set of Ca2+/K+ membrane conductances which enable them to produce rhythmic oscillatory activities. In vivo, studies of Ca(2+)-conductance blockade by intrathalamic injections of Cd2+ were performed on 24 callosotomized Wistar rats displaying spontaneous SW discharges, bred at the Centre de Neurochimie, Strasbourg. A significant decrement in ipsilateral SW activity was consistently observed in all RTN-injected animals 40 min after Cd2+ injection. By contrast, animals which received Cd2+ injection into the ventroposterior complex (VP) showed only small changes in ipsilateral SW. It is concluded that Ca(2+)-dependent oscillatory properties of the RTN are critical for the expression of genetically determined SW discharges in the Wistar model.
Avanzini
G
G
Istituto Neurologico C. Besta, Milano, Italy.
de Curtis
M
M
Marescaux
C
C
Panzica
F
F
Spreafico
R
R
Vergnes
M
M
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D009474:Neurons / Q000502:physiology; D010507:Periodicity; D051381:Rats; D011919:Rats, Inbred Strains; D013787:Thalamic Nuclei / Q000166:cytology / Q000502:physiology*; D013788:Thalamus / Q000502:physiology*
D002121:Calcium Channel Blockers; D002104:Cadmium