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Cumulative depolarization of Hermissenda type B photoreceptors, a short-term neural correlate of associative learning, was produced by simulating associative training in the isolated nervous system (in vitro conditioning). This simulation entailed stimulation and recording from three classes of neurons normally affected by the associative training(More)
Learning behavior similar to vertebrate classical conditioning was demonstrated for the mollusc Hermissenda crassicornis. Postsynaptic membrane changes within well-defined neural systems that mediate the learning play a casual role in recording the learned association for later recall. Specific ionic currents in neural tissue undergo transformations lasting(More)
Intradendritic recordings in Purkinje cells from a defined area in parasaggital slices of cerebellar lobule HVI, obtained after rabbits were given either paired (classical conditioning) or explicitly unpaired (control) presentations of tone and periorbital electrical stimulation, were used to assess the nature and duration of conditioning-specific changes(More)
Single type B photoreceptors in intact, restrained Hermissenda were impaled with a microelectrode and exposed to either paired or unpaired presentations of light and depolarizing current to simulate natural stimulus effects during conditioning with light and rotation. Paired, but not unpaired, stimulus presentations produced cumulative depolarization and(More)
Training of the marine snail Hermissenda crassicornis with paired light and rotation was previously shown to result in acquisition and retention of a behavioral change with many features characteristic of vertebrate associative learning. Here, this behavioral change is demonstrated to be classical, Pavlovian-like conditioning. A new response to light is(More)
Two-microelectrode voltage clamp studies were performed on the somata of Hermissenda Type B photoreceptors that had been isolated by axotomy from all synaptic interaction as well as any impulse-generating (i.e., active) membrane. In the presence of 2-10 mM 4-aminopyridine (4-AP) and 100 mM tetraethylammonium ion (TEA), which eliminated two previously(More)
Evidence accumulated from clinical and basic research has indirectly implicated the insulin receptor (IR) in brain cognitive functions, including learning and memory (Wickelgren, I. (1998) Science 280, 517-519). The present study investigates correlative changes in IR expression, phosphorylation, and associated signaling molecules in the rat hippocampus(More)
1. The afterhyperpolarization (AHP) that follows action potentials was studied in CA1 hippocampal pyramidal cells from classically conditioned and control rabbits. Measurements of the AHP were obtained with intracellular recordings from CA1 cells within hippocampal slices. 2. The AHP of rabbit CA1 pyramidal cells was found to be accompanied by a conductance(More)