scholarly journals Yoked comparisons of instrumental-avoidance and classical conditioning of the rabbit nictitating membrane response as a function of interstimulus interval and number of trials per day

1968 ◽  
Vol 12 (3) ◽  
pp. 93-94 ◽  
Author(s):  
Ralph B. Hupka ◽  
Dominic W. Massaro ◽  
John W. Moore
Keyword(s):  
Classical Conditioning ◽  
Interstimulus Interval ◽  
Nictitating Membrane ◽  
Nictitating Membrane Response

Single-unit analysis of different hippocampal cell types during classical conditioning of rabbit nictitating membrane response

1983 ◽  
Vol 50 (5) ◽  
pp. 1197-1219 ◽  
Author(s):  
T. W. Berger ◽  
P. C. Rinaldi ◽  
D. J. Weisz ◽  
R. F. Thompson
Keyword(s):  
Classical Conditioning ◽  
Pyramidal Cell ◽  
Action Potentials ◽  
Pyramidal Cells ◽  
Cell Types ◽  
Firing Frequency ◽  
Spontaneous Firing ◽  
Nictitating Membrane ◽  
Nictitating Membrane Response ◽  
Firing Characteristics

Extracellular single-unit recordings from neurons in the CA1 and CA3 regions of the dorsal hippocampus were monitored during classical conditioning of the rabbit nictitating membrane response. Neurons were classified as different cell types using response to fornix stimulation (i.e., antidromic or orthodromic activation) and spontaneous firing characteristics as criteria. Results showed that hippocampal pyramidal neurons exhibit learning-related neural plasticity that develops gradually over the course of classical conditioning. The learning-dependent pyramidal cell response is characterized by an increase in frequency of firing within conditioning trials and a within-trial pattern of discharge that correlates strongly with amplitude-time course of the behavioral response. In contrast, pyramidal cell activity recorded from control animals given unpaired presentations of the conditioned and unconditioned stimulus (CS and UCS) does not show enhanced discharge rates with repeated stimulation. Previous studies of hippocampal cellular electrophysiology have described what has been termed a theta-cell (19-21, 45), the activity of which correlates with slow-wave theta rhythm generated in the hippocampus. Neurons classified as theta-cells in the present study exhibit responses during conditioning that are distinctly different than pyramidal cells. theta-Cells respond during paired conditioning trials with a rhythmic bursting; the between-burst interval occurs at or near 8 Hz. In addition, two different types of theta-cells were distinguishable. One type of theta-cell increases firing frequency above pretrial levels while displaying the theta bursting pattern. The other type decreases firing frequency below pretrial rates while showing a theta-locked discharge. In addition to pyramidal and theta-neurons, several other cell types recorded in or near the pyramidal cell layer could be distinguished. One cell type was distinctive in that it could be activated with a short, invariant latency following fornix stimulation, but spontaneous action potentials of such neurons could not be collided with fornix shock-induced action potentials. These neurons exhibit a different profile of spontaneous firing characteristics than those of antidromically identified pyramidal cells. Nevertheless, neurons in this noncollidable category display the same learning-dependent response as pyramidal cells. It is suggested that the noncollidable neurons represent a subpopulation of pyramidal cells that do not project an axon via the fornix but project, instead, to other limbic cortical regions.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of Unpaired Pre-Acquisition Exposure of CS and UCS on Classical Conditioning of the Nictitating Membrane Response of the Albino Rabbit

1964 ◽  
Vol 15 (2) ◽  
pp. 571-576 ◽  
Author(s):  
Milton D. Suboski ◽  
Vincent di Lollo ◽  
I. Gormezano
Keyword(s):  
Classical Conditioning ◽  
Spontaneous Recovery ◽  
Acquisition Training ◽  
Albino Rabbit ◽  
Nictitating Membrane ◽  
Resistance To Extinction ◽  
Nictitating Membrane Response

The effects of the presentation, prior to acquisition training of (1) “no stimulation,” (2) CS alone trials, (3) UCS alone trials, and (4) CS-UCS unpaired trials were investigated in conditioning and extinction of the nictitating membrane response. The principal findings were: (a) significantly higher blink rates in adaptation for the groups receiving the UCS, (b) no differences among groups in acquisition, (c) greater resistance to extinction by groups receiving the CS in adaptation, as evidenced by significant differences in spontaneous recovery, and (d) a significant over-all increase in UCR magnitude in adaptation and acquisition.

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