scholarly journals The engram found? Role of the cerebellum in classical conditioning of nictitating membrane and eyelid responses

1981 ◽  
Vol 18 (3) ◽  
pp. 103-105 ◽  
Author(s):  
David A. Mccormick ◽  
David G. Lavond ◽  
Gregory A. Clark ◽  
Ronald E. Kettner ◽  
Christina E. Rising ◽  
...  
Keyword(s):  
Classical Conditioning ◽  
Nictitating Membrane

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)

Plasticity: Cells, Circuits, Brains, and Behavior

2016 ◽  
Author(s):  
Patricia S. Churchland ◽  
Terrence J. Sejnowski
Keyword(s):  
Nervous System ◽  
Synaptic Plasticity ◽  
Classical Conditioning ◽  
Neuronal Plasticity ◽  
Neural Mechanism ◽  
Synaptic Strength ◽  
Physical Mechanisms ◽  
And Behavior ◽  
The Brain

This chapter examines the physical mechanisms in nervous systems in order to elucidate the structural bases and functional principles of synaptic plasticity. Neuroscientific research on plasticity can be divided into four main streams: the neural mechanism for relatively simple kinds of plasticity, such as classical conditioning or habituation; anatomical and physiological studies of temporal lobe structures, including the hippocampus and the amygdala; study of the development of the visual system; and the relation between the animal's genes and the development of its nervous system. The chapter first considers the role of the mammalian hippocampus in learning and memory before discussing Donald Hebb's views on synaptic plasticity. It then explores the mechanisms underlying neuronal plasticity and those that decrease synaptic strength, the relevance of time with respect to plasticity, and the occurrence of plasticity during the development of the nervous system. It also describes modules, modularity, and networks in the brain.

scholarly journals Should we essentially ignore the role of stimuli in a general account of operant selection?

2001 ◽  
Vol 24 (3) ◽  
pp. 528-529
Author(s):  
Rick A. Bevins
Keyword(s):  
Classical Conditioning ◽  
Environmental Interaction ◽  
General Account

The selectionist account of behavior is actually a focused discussion of operant selection. To this end, the authors essentially exclude stimuli from their analysis. This exclusion is inconsistent with the importance placed on environmental interaction in their general account. Further, this exclusion limits the generality of their account by missing important sources of stimulus-elicited behavior (e.g., classical conditioning).

scholarly journals Cyclic AMP-dependent plasticity underlies rapid changes in odor coding associated with reward learning

2017 ◽  
Vol 115 (3) ◽  
pp. E448-E457 ◽  
Author(s):  
Thierry Louis ◽  
Aaron Stahl ◽  
Tamara Boto ◽  
Seth M. Tomchik
Keyword(s):  
Classical Conditioning ◽  
Reward Learning ◽  
Camp Signaling ◽  
Type I ◽  
Appetitive Conditioning ◽  
Dependent Plasticity ◽  
Olfactory Responses ◽  
Neuronal Physiology

Learning and memory rely on dopamine and downstream cAMP-dependent plasticity across diverse organisms. Despite the central role of cAMP signaling, it is not known how cAMP-dependent plasticity drives coherent changes in neuronal physiology that encode the memory trace, or engram. In Drosophila, the mushroom body (MB) is critically involved in olfactory classical conditioning, and cAMP signaling molecules are necessary and sufficient for normal memory in intrinsic MB neurons. To evaluate the role of cAMP-dependent plasticity in learning, we examined how cAMP manipulations and olfactory classical conditioning modulate olfactory responses in the MB with in vivo imaging. Elevating cAMP pharmacologically or optogenetically produced plasticity in MB neurons, altering their responses to odorants. Odor-evoked Ca2+ responses showed net facilitation across anatomical regions. At the single-cell level, neurons exhibited heterogeneous responses to cAMP elevation, suggesting that cAMP drives plasticity to discrete subsets of MB neurons. Olfactory appetitive conditioning enhanced MB odor responses, mimicking the cAMP-dependent plasticity in directionality and magnitude. Elevating cAMP to equivalent levels as appetitive conditioning also produced plasticity, suggesting that the cAMP generated during conditioning affects odor-evoked responses in the MB. Finally, we found that this plasticity was dependent on the Rutabaga type I adenylyl cyclase, linking cAMP-dependent plasticity to behavioral modification. Overall, these data demonstrate that learning produces robust cAMP-dependent plasticity in intrinsic MB neurons, which is biased toward naturalistic reward learning. This suggests that cAMP signaling may serve to modulate intrinsic MB responses toward salient stimuli.

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