[Effects of 6-OHDA lesions of the bilateral dorsal noradrenergic bundle on learning-dependent long-term synaptic potentiation in dentate gyrus].
In the present study, the role of NE in learning-dependent long-term potentiation (LdLTP) was investigated by examining the effects of 6-hydroxydopamine (6-OHDA) lesion made in the bilateral dorsal noradrenergic bundle on the changes of synaptic efficacy in dentate gyrus (DG) and related conditioned response during drinking conditioning. Bilateral injection of 6-OHDA (12 micrograms/4 microliters) into the dorsal noradrenergic bundle caused a continuous decrease of the amplitude of population spike (PS) reaching a value of 50 +/- 6.3% and 28 +/- 6.4% respectively at the 6th and the 12th day after injection of the drug. During this period of 7 days, the LdLTP could not be produced in spite of 20 trainings per day for a total of 140 trials, and the conditioned drinking response could not be established. The above results indicate that normal levels of norepinephrine in the hippocampus are necessary to the establishment of LdLTP in the DG and suggest that the development of LdLTP in the DG may be modulated by the nucleus locus ceruleus via the dorsal noradrenergic bundle.
Song
Y P
YP
Neurophysiology Research Laboratory, South China Normal University, Guangzhou.
Xu
S T
ST
Ou
Y Q
YQ
D000818:Animals; D004594:Electrophysiology; D006624:Hippocampus / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D008125:Locus Coeruleus / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism / Q000502:physiology*; D016627:Oxidopamine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000502:physiology
D016627:Oxidopamine; D009638:Norepinephrine