title: Septal elicitation of hippocampal theta rhythm did not repair cognitive and emotional deficits resulting from vestibular lesions.
abstract: Bilateral vestibular lesions cause atrophy of the hippocampus in humans and subsequent deficits in spatial memory and the processing of emotional stimuli in both rats and humans. Vestibular lesions also impair hippocampal theta rhythm in rats. The aim of the present study was to investigate whether restoring theta rhythm to the hippocampus of a rat, via stimulation of the medial septum, would repair the deficits caused by vestibular lesions. It was hypothesized that the restoration of theta would repair the deficits and the vestibular rats would exhibit behavior and EEG similar to that of the sham rats. Rats were given either sham surgery or bilateral vestibular deafferentation (BVD) followed in a later operation by electrode implants. Half of the lesioned rats received stimulation. Subjects were tested in open field, elevated T-maze and spatial nonmatching to sample tests. BVD caused a deficit in hippocampal theta rhythm. Stimulation restored theta power at a higher frequency in the vestibular-lesioned rats, however, the stimulation did not repair the cognitive and emotional deficits caused by the lesions. It was concluded that stimulation, at least in the form used here, would not be a viable treatment option for vestibular damaged humans.
authors: Department of Psychology, University of Otago, Dunedin, New Zealand.
authors: Phoebe
authors: P
authors: Neo
authors: Donna
authors: D
authors: Carter
authors: Yiwen
authors: Y
authors: Zheng
authors: Paul
authors: P
authors: Smith
authors: Cynthia
authors: C
authors: Darlington
authors: Neil
authors: N
authors: McNaughton
mesh_terms: D000818:Animals; D001007:Anxiety / Q000503:physiopathology; D004558:Electric Stimulation; D004569:Electroencephalography; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D008569:Memory Disorders / Q000473:pathology / Q000503:physiopathology; D009475:Neurons, Afferent / Q000502:physiology; D011434:Proprioception / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020665:Septum of Brain / Q000503:physiopathology*; D013028:Space Perception / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology; D013826:Theta Rhythm; D015837:Vestibular Diseases / Q000473:pathology / Q000503:physiopathology*; D014722:Vestibule, Labyrinth / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery