Modulation of spatial alternation and anxiety by septal scopolamine systemic diazepam in mice.
To investigate the behavioral consequences of benzodiazepines in subjects whose septo-hippocampal cholinergic (ACh) activity was impaired, C57BL/6 mice received an injection of 2.5 microg/0.2 microl of scopolamine into the medial septal area with an i.p. injection of 0.5 mg/kg of diazepam. The consequences of these treatments administered in combination or alone were evaluated on anxiety measured in an elevated plus-maze and on spontaneous alternation carried out in a T-maze, using two different intertrial intervals (ITI: 5s or 30s). In these conditions, only the combined treatment provoked a decrease of the anxiety level, which was associated with an impairment of spontaneous alternation restricted to the 5s ITI. Because mice were not impaired during the sequential 30s ITI, this seems to rule out the possibility that this alternation deficit resulted from a working memory loss. These results suggest an involvement of a septal ACh-GABA-A/BDZ interaction in the exaggeration of cognitive deficits produced by benzodiazepines in patients characterized by a cholinergic hypofunction.
Laboratoire de Neurosciences Comportementales et Cognitives, CNRS URA 339, Université de Bordeaux I, Talence, France.
M
M
Belotti
B
B
Cagniard
M P
MP
Mano
D
D
Galey
D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000188:drug therapy*; D001921:Brain / Q000033:anatomy & histology; D001923:Brain Chemistry / Q000187:drug effects*; D003975:Diazepam / Q000494:pharmacology*; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D012601:Scopolamine / Q000494:pharmacology*; D013028:Space Perception / Q000187:drug effects*
D014151:Anti-Anxiety Agents; D018727:Muscarinic Antagonists; D012601:Scopolamine; D003975:Diazepam