scholarly journals Trace eyeblink conditioning is associated with changes in synaptophysin immunoreactivity in the cerebellar interpositus nucleus in guinea pigs

2018 ◽  
Vol 38 (3) ◽  
Author(s):  
Rui Li ◽  
Qi Li ◽  
Xiao-Lei Chu ◽  
Tao Tao ◽  
Lan Li ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Guinea Pigs ◽  
Transmembrane Protein ◽  
Eyeblink Conditioning ◽  
Trace Conditioning ◽  
Interpositus Nucleus ◽  
Important Indicator ◽  
Cerebellar Interpositus Nucleus ◽  
Immunohistochemical Techniques ◽  
Trace Eyeblink Conditioning

Synaptic plasticity plays a role during trace eyeblink conditioning (TEBC). Synaptophysin (Syn) is a major integral transmembrane protein, located particularly in the synaptic vesicles, and is considered a molecular marker of synapses. In addition, Syn immunoreactivity is an important indicator of synaptic plasticity. In the present study, we used immunohistochemical techniques to assess changes in Syn expression in the cerebellar interpositus nucleus (IN) of guinea pigs exposed to TEBC and pseudoconditioning. Additionally, we analyzed the relationship between Syn immunoreactivity and the percentage of trace-conditioned responses. Guinea pigs underwent trace conditioning or pseudoconditioning. Following two, six, or ten sessions, they were perfused and the cerebellum was removed for Syn immunohistochemical evaluation. After sessions 6 and 10, a significant increase in conditioned response (CR) percentage was observed in the trace-conditioned group, with the CR percentage reaching the learning criteria following session 10. Besides, for trace-conditioned animals, the Syn expression in IN was found significantly up-regulated after session 10 compared with pseudoconditioned ones. Our data suggest that the increase in Syn expression links to synaptic plasticity changes in the cerebellar IN and provides a histological substrate in the IN relating to TEBC training. The changing trend of Syn immunoreactivity in the IN is associated with CR percentage.

Trace eyeblink conditioning in decerebrate guinea pigs

2003 ◽  
Vol 17 (7) ◽  
pp. 1445-1454 ◽  
Author(s):  
Sadaharu Kotani ◽  
Shigenori Kawahara ◽  
Yutaka Kirino
Keyword(s):  
Guinea Pigs ◽  
Eyeblink Conditioning ◽  
Trace Eyeblink Conditioning

A NEURAL NETWORK MODEL FOR TRACE CONDITIONING

2005 ◽  
Vol 15 (01n02) ◽  
pp. 23-30 ◽  
Author(s):  
TADASHI YAMAZAKI ◽  
SHIGERU TANAKA
Keyword(s):  
Neural Network ◽  
Eyeblink Conditioning ◽  
Activity Patterns ◽  
Trace Conditioning ◽  
Transient Signal ◽  
Transient Signals ◽  
Ca1 Neurons ◽  
Sustained Activity ◽  
Output Neuron ◽  
Trace Eyeblink Conditioning

We studied the dynamics of a neural network that has both recurrent excitatory and random inhibitory connections. Neurons started to become active when a relatively weak transient excitatory signal was presented and the activity was sustained due to the recurrent excitatory connections. The sustained activity stopped when a strong transient signal was presented or when neurons were disinhibited. The random inhibitory connections modulated the activity patterns of neurons so that the patterns evolved without recurrence with time. Hence, a time passage between the onsets of the two transient signals was represented by the sequence of activity patterns. We then applied this model to represent the trace eyeblink conditioning, which is mediated by the hippocampus. We assumed this model as CA3 of the hippocampus and considered an output neuron corresponding to a neuron in CA1. The activity pattern of the output neuron was similar to that of CA1 neurons during trace eyeblink conditioning, which was experimentally observed.

Activity Profiles of Single Neurons in Caudal Anterior Cingulate Cortex During Trace Eyeblink Conditioning in the Rabbit

2003 ◽  
Vol 90 (2) ◽  
pp. 599-612 ◽  
Author(s):  
Aldis P. Weible ◽  
Craig Weiss ◽  
John F. Disterhoft
Keyword(s):  
Anterior Cingulate Cortex ◽  
Neuronal Activity ◽  
Eyeblink Conditioning ◽  
Neuronal Response ◽  
Trace Conditioning ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Excitatory Response ◽  
Excitatory Responses ◽  
Trace Eyeblink Conditioning

Acquisition of trace eyeblink conditioning involves the association of a conditioned stimulus (CS) with an unconditioned stimulus (US) separated by a stimulus-free trace interval. This form of conditioning is dependent upon the hippocampus and the caudal anterior cingulate cortex (AC), in addition to brain stem and cerebellar circuitry. Hippocampal involvement in trace eyeblink conditioning has been studied extensively, but the involvement of caudal AC is less well understood. In the present study, we compared neuronal responses from rabbits given either paired (trace conditioning) or unpaired (pseudoconditioning) presentations of the CS and US. Presentation of the CS elicited significant increases in neuronal activity at the onset of both trace conditioning and pseudoconditioning. A robust CS-elicited neuronal response persisted throughout the first 2 days of trace conditioning, declining gradually across subsequent training sessions. In contrast, the magnitude of the CS-elicited excitatory response during pseudoconditioning began to decline within the first 10 trials. Neurons exhibiting excitatory responses to the CS during trace conditioning also exhibited excitatory responses to the US that were significantly greater in magnitude than US-elicited responses during pseudoconditioning. CS-elicited decreases in neuronal activity became more robust over the course of trace conditioning compared to pseudoconditioning. Reductions in activity during the CS interval consistently preceded excitation in both training groups, suggesting that the CS-elicited decreases in neuronal activity may serve to increase the signal-to-noise ratio of the excitatory response to the tone. Taken together, these data suggest that the caudal AC is involved early in trace eyeblink conditioning and that maintenance of the CS-elicited excitatory response may serve to signal the salience of the tone.

scholarly journals Aging and Learning-Specific Changes in Single-Neuron Activity in CA1 Hippocampus During Rabbit Trace Eyeblink Conditioning

2001 ◽  
Vol 86 (4) ◽  
pp. 1839-1857 ◽  
Author(s):  
Matthew D. McEchron ◽  
Aldis P. Weible ◽  
John F. Disterhoft
Keyword(s):  
Pyramidal Cell ◽  
Single Neuron ◽  
Eyeblink Conditioning ◽  
Pyramidal Cells ◽  
Trace Conditioning ◽  
Neuron Activity ◽  
Single Neurons ◽  
Cell Firing ◽  
Trace Eyeblink Conditioning ◽  
Single Neuron Activity

Rabbit trace eyeblink conditioning is a hippocampus-dependent task in which the auditory conditioned stimulus (CS) is separated from the corneal airpuff unconditioned stimulus (US) by a 500-ms empty trace interval. Young rabbits are able to associate the CS and US and acquire trace eyeblink conditioned responses (CRs); however, a subset of aged rabbits show poor learning on this task. Several studies have shown that CA1-hippocampal activity is altered by aging; however, it is unknown how aging affects the interaction of CA1 single neurons within local ensembles during learning. The present study examined the extracellular activity of CA1 pyramidal neurons within local ensembles in aged (29–34 mo) and young (3–6 mo) rabbits during 10 daily sessions (80 trials/session) of trace eyeblink conditioning. A single surgically implanted nonmovable stereotrode was used to record ensembles ranging in size from 2 to 12 separated single neurons. A total of six young and four aged rabbits acquired significant levels of CRs, whereas five aged rabbits showed very few CRs similar to a group of five young pseudoconditioned rabbits. Pyramidal cells (2,159 total) were recorded from these four groups during training. Increases in CA1 pyramidal cell firing to the CS and US were diminished in the aged nonlearners. Local ensembles from all groups contained heterogeneous types of pyramidal cell responses. Some cells showed increases while others showed decreases in firing during the trace eyeblink trial. Hierarchical clustering was used to isolate seven different classes of single-neuron responses that showed unique firing patterns during the trace conditioning trial. The proportion of cells in each group was similar for six of seven response classes. Unlike the excitatory modeling patterns reported in previous studies, three of seven response types (67% of recorded cells) exhibited some type of inhibitory decrease to the CS, US, or both. The single-neuron response classes showed different patterns of learning-related activity across training. Several of the single-neuron types from the aged nonlearners showed unique alterations in response magnitude to the CS and US. Cross-correlation analyses suggest that specific single-neuron types provide more correlated single-neuron activity to the ensemble processing of information. However, aged nonlearners showed a significantly lower level of coincident pyramidal cell firing for all cell types within local ensembles in CA1.

Sign in / Sign up

Export Citation Format

Share Document