Fimbria-fornix lesion impairs long-term potentiation in the dentate gyrus of the rat.
Bilateral aspiration lesions of the fimbria-fornix were performed in 10 male Sprague Dawley rats weighing 240-300 g under chloral hydrate narcose (420 mg/kg). Another 9 animals were operated in the same way, but no aspiration was carried out to constitute a control group. A week after surgery recording and stimulation electrodes were lowered to the dentate gyrus and the perforant path respectively, using the same narcose. After tetanic stimulation (10 trains at 400 Hz) a potentiation of the population spike develops in both groups, but the slope of the excitatory postsynaptic potential showed no potentiation in the lesioned group. Acetylcholinesterase histochemistry confirmed a severe reduction of the cholinergic innervation to the hippocampal formation, suggesting a causal relationship to the deficits seen in long-term potentiation. This impaired potentiation could be related to the memory deficits reported for fimbria-fornix lesioned rats. Such pattern of potentiation deviates from what has been described for aged, memory deficient rats, but closely corresponds to the changes described in infantile rats.
Bergado
J A
JA
Centro Internacional de Restauración Neurológica, La Habana, Cuba. neuro@cenia.cu
Moreno
H
H
Nuñez
N
N
D000110:Acetylcholinesterase / Q000378:metabolism*; D000328:Adult; D000818:Animals; D018891:Dentate Gyrus / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000110:Acetylcholinesterase