Stimulation of the lateral hypothalamus provokes the initiation of robust long-term potentiation of the thalamo-cortical input to the barrel field of the adult, freely moving rat.

Détails

ID Serval
serval:BIB_7BED3E7CA6C8
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Stimulation of the lateral hypothalamus provokes the initiation of robust long-term potentiation of the thalamo-cortical input to the barrel field of the adult, freely moving rat.
Périodique
Neuroscience and behavioral physiology
Auteur(s)
Ezrokhi V.L., Korshunov V.A., Markevich V.A., Voronin L.L., Welker E., Zajchenko M.I.
ISSN
0097-0549
Statut éditorial
Publié
Date de publication
11/2004
Volume
34
Numéro
9
Pages
919-927
Langue
anglais
Notes
Publication types: Comparative Study ; Journal Article. - Old month value: Nov
Résumé
Long-term potentiation in the thalamo-cortical input to the somatosensory cortex barrel field has been reported to be inducible in vitro only during a narrow critical period of the first postnatal week. Here we explored whether this is due to inability of adult synapses to express LTP or lack of appropriate conditions for LTP induction in slice preparations. We recorded thalamo-cortical field potentials (FPs) from the barrel field of chronically prepared adult rats. In the first series, several parameters of conditioning tetanization of thalamus (T) have been tried. Statistically significant LTP of 135-150% relative to the baseline was observed only in rare cases (3/18) so that the mean changes were not statistically significant. In the second series, five trains of 100 Hz stimulation of T were paired with a "reinforcing" stimulation of the lateral hypothalamus (LH). In most cases (9/13), thalamo-cortical FPs were potentiated. The mean post-tetanic amplitude was 238 +/- 42% (+/- SEM) relative to the baseline (n = 13). The potentiation persisted for >1 h and typically even further increased when tested 24-48 h later. LTP magnitude strongly correlated with the initial paired-pulse ratio (PPR, coefficient of correlation r = 0.98) so that the LTP magnitude was larger (333 +/- 107, n = 6) in cases with PPR > 1.3. The mean PPR tended to decrease after LTP (from 2.05 to 1.65). Altogether the results suggest that LTP is inducible in the thalamo-cortical input to the barrel field of normal adult rats. The dependence of the LTP magnitude upon the initial PPR suggests that inputs with low initial release probability undergo larger LTP. Together with the tendency to a decrease in the PPR this suggests an involvement of presynaptic mechanisms in the maintenance of neocortical LTP.
Mots-clé
Animals, Electric Stimulation/methods, Evoked Potentials/physiology, Evoked Potentials/radiation effects, Hypothalamus/physiology, Hypothalamus/radiation effects, Linear Models, Long-Term Potentiation/physiology, Long-Term Potentiation/radiation effects, Neural Pathways/physiology, Neural Pathways/radiation effects, Rats, Rats, Wistar, Somatosensory Cortex/physiology, Somatosensory Cortex/radiation effects, Thalamus/physiology, Time Factors, Wakefulness/radiation effects
Pubmed
Création de la notice
24/01/2008 15:40
Dernière modification de la notice
03/03/2018 18:36
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