John H McLean9
Susan G Walling7
9John H McLean
7Susan G Walling
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Rats were trained to locate food in a response, direction, or place problem on an open field located at 2 positions. In Experiment 1, both the response and direction groups solved the problem. The place group failed to solve the task in approximately 300 trials. Experiment 2 demonstrated that rats need distinguishable start points to solve a place problem(More)
Theta and gamma oscillations are thought to provide signal sets that promote neural coding of cognitive processes. Over 40 yrs ago, Jeffrey Gray reported event-related changes in a narrow band of hippocampal theta (7.5-8.5 Hz) which appeared to involve norepinephrine (NE) release from, the noradrenergic nucleus, the locus coeruleus (LC). These event-related(More)
Open field and T-maze paradigms are used to test the effects of hippocampal lesions on spatial memory in rodents. Place cells in the dorsal CA1 region of the hippocampus are known to be responsible for the formation of global place maps, while CA3 neurons respond to changes in local contexts. It is proposed here that when dorsal CA1 is selectively(More)
BACKGROUND β-adrenoceptor activation in the hippocampus is sufficient to induce heterosynaptic long-term potentiation of perforant path input to the dentate gyrus. However, in vitro and in vivo studies suggest the plasticity effects of β-adrenoceptor activation may vary depending on the level of receptor activation. METHODS The present experiments use an(More)
The locus ceruleus is activated by novel stimuli, and its activation promotes learning and memory. Phasic activation of locus ceruleus neurons by glutamate enhances the dentate gyrus population spike amplitude and results in long-term potentiation of synaptic responses recorded after 24 h. Cholinergic activation of locus ceruleus neurons increases(More)
The orexins (ORX-A/ORX-B) are neuroactive peptides known to have roles in feeding and sleep. Evidence of dense, excitatory projections of ORX-A neurons to the noradrenergic pontine nucleus, the locus ceruleus (LC), suggests ORX-A also participates in attention and memory. Activation of LC neurons by glutamate produces a beta-adrenergic receptor-mediated(More)
In the present study we assess a new model for classical conditioning of odor preference learning in rat pups. In preference learning beta(1)-adrenoceptors activated by the locus coeruleus mediate the unconditioned stimulus, whereas olfactory nerve input mediates the conditioned stimulus, odor. Serotonin (5-HT) depletion prevents odor learning, with(More)
Place learning is impaired when a single plus maze is moved between adjacent locations 33-120 cm apart. This maze translation creates distinct start locations but maintains a single goal location with respect to distal cues. Hippocampal cell recording data suggest the majority of place fields are tied to apparatus boundaries, not to distal cues, when an(More)