Michael D Bunsey

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Normal rats rapidly acquire and remember associations between nonspatial stimuli as expressed in the social transmission of food preferences. In the present study, rats with selective neurotoxic lesions including all subdivisions of the hippocampal region (hippocampus proper, dentate gyrus, and subiculum) normally acquired and briefly retained the food odor(More)
The typical catalepsy test consists of placing an animal into an unusual posture and recording the time taken to correct this posture. This time is regarded as an index of the intensity of catalepsy. Catalepsy is a robust behavior, and the lack of standardization does not usually hinder its actual detection. However, the intensity of the cataleptic effect(More)
In humans declarative or explicit memory is supported by the hippocampus and related structures of the medial temporal lobe working in concert with the cerebral cortex. This paper reviews our progress in developing an animal model for studies of cortical-hippocampal interactions in memory processing. Our findings support the view that the cortex maintains(More)
Human amnesics are severely impaired in learning arbitrary associations between word pairs. This report examines the role of the hippocampal system in an analog of paired-associate learning developed for rats. Subjects with selective damage to the parahippocampal region and controls were tested on an odor-guided paired-associate task. Normal rats readily(More)
Rats were injected with the alpha 2-adrenergic antagonist idazoxan (IDZ) prior to testing on vigilance and distraction tasks. In the vigilance task, rats responded with nose pokes to brief visual cues presented at variable intervals following trial onset. The distraction task was similar except that irrelevant odor cues (distractors) were presented in the(More)
The role of the hippocampal system in retrograde and anterograde amnesia was investigated by using a novel olfactory-guided paradigm and a traditional test of spatial learning. In the retrograde study, rats were trained on a sequence of two-choice olfactory discriminations in the weeks prior to receiving neurotoxic lesions of the hippocampus or aspiration(More)
Several studies have demonstrated that dorsal, but not ventral, hippocampus is critical for spatial memory. The mnemonic role of the ventral hippocampus remains unclear. The existence of relatively direct connections between hypothalamic nuclei and ventral hippocampus suggests that the ventral hippocampus may be involved in acquisition of information(More)
The present study was designed to provide further information on the enduring cognitive effects of experimental phenylketonuria (PKU) in rats, produced by the administration of alpha-methylphenylalanine and phenylalanine on postnatal days 3-21. These rats evidenced: (1) impaired learning set formation, (2) stimulus perseveration, particularly after an(More)
Two studies were conducted to test the ability of post-trial amphetamine treatment to improve later recall in a nonaversively motivated task. These studies utilized 8- and 12-arm radial mazes, respectively, with an 11-h retention interval imposed after the rat traversed half the arms of the maze (termed, the to-be-remembered-event, or TBRE). In Experiment(More)