scholarly journals Infragranular barrel cortex activity is enhanced with learning

2012 ◽  
Vol 108 (5) ◽  
pp. 1278-1287 ◽  
Author(s):  
Rebekah L. Ward ◽  
Luke C. Flores ◽  
John F. Disterhoft
Keyword(s):  
Single Unit ◽  
Barrel Cortex ◽  
Eyeblink Conditioning ◽  
Sensory Cortex ◽  
Learning Criterion ◽  
Extracellular Recordings ◽  
Primary Sensory Cortex ◽  
Whisker Stimulation ◽  
Trace Eyeblink Conditioning

The barrel cortex (BC) is essential for the acquisition of whisker-signaled trace eyeblink conditioning and shows learning-related expansion of the trained barrels after the acquisition of a whisker-signaled task. Most previous research examining the role of the BC in learning has focused on anatomic changes in the layer IV representation of the cortical barrels. We studied single-unit extracellular recordings from individual neurons in layers V and VI of the BC as rabbits acquired the whisker-signaled trace eyeblink conditioning task. Neurons in layers V and VI in both conditioned and pseudoconditioned animals robustly responded to whisker stimulation, but neurons in conditioned animals showed a significant enhancement in responsiveness in concert with learning. Learning-related changes in firing rate occurred as early as the day of learning criterion within the infragranular layers of the primary sensory cortex.

scholarly journals Hippocampal Interneurons are Required for Trace Eyeblink Conditioning in Mice

2021 ◽  
Author(s):  
Wei-Wei Zhang ◽  
Rong-Rong Li ◽  
Jie Zhang ◽  
Jie Yan ◽  
Qian-Hui Zhang ◽  
...  
Keyword(s):  
Eyeblink Conditioning ◽  
Pyramidal Cells ◽  
Conditioned Eyeblink ◽  
Cellular Mechanisms ◽  
Sustained Activity ◽  
Early Acquisition ◽  
Freely Moving ◽  
Trace Eyeblink Conditioning

AbstractWhile the hippocampus has been implicated in supporting the association among time-separated events, the underlying cellular mechanisms have not been fully clarified. Here, we combined in vivo multi-channel recording and optogenetics to investigate the activity of hippocampal interneurons in freely-moving mice performing a trace eyeblink conditioning (tEBC) task. We found that the hippocampal interneurons exhibited conditioned stimulus (CS)-evoked sustained activity, which predicted the performance of conditioned eyeblink responses (CRs) in the early acquisition of the tEBC. Consistent with this, greater proportions of hippocampal pyramidal cells showed CS-evoked decreased activity in the early acquisition of the tEBC. Moreover, optogenetic suppression of the sustained activity in hippocampal interneurons severely impaired acquisition of the tEBC. In contrast, suppression of the sustained activity of hippocampal interneurons had no effect on the performance of well-learned CRs. Our findings highlight the role of hippocampal interneurons in the tEBC, and point to a potential cellular mechanism subserving associative learning.

Role of Primary Sensory Cortex in Generalized Electrocortical Activation

1957 ◽  
Vol 189 (1) ◽  
pp. 137-140
Author(s):  
Aaron J. Beller ◽  
Gidon F. Gestring ◽  
Dominick P. Purpura
Keyword(s):  
Sensory Stimulation ◽  
Sensory Cortex ◽  
Activation Process ◽  
Afferent Activity ◽  
Primary Sensory Cortex ◽  
Cortical Regions ◽  
Somatic Sensory Cortex ◽  
Bilateral Destruction

Experiments were performed on intact unanesthetized-succinylcholine paralyzed cats in order to compare the effects of ablations of primary cortical regions on the ability to evoke generalized activation to specific sensory stimulation with those obtained by Bremer on encéphale isolé preparations. Bilateral destruction of the auditory or somatic sensory cortex in intact preparations does not block generalized activation to auditory or sciatic stimulation. It is concluded that in the presence of spinal afferent activity as exists in the intact preparation corticifugal influences arising in either the auditory or somatic sensory cortex are not necessary for the activation process that follows auditory or sciatic stimulation.

Time-limited role of the hippocampus in the memory for trace eyeblink conditioning in mice

2002 ◽  
Vol 951 (2) ◽  
pp. 183-190 ◽  
Author(s):  
Kaori Takehara ◽  
Shigenori Kawahara ◽  
Kanako Takatsuki ◽  
Yutaka Kirino
Keyword(s):  
Eyeblink Conditioning ◽  
Limited Role ◽  
Trace Eyeblink Conditioning

scholarly journals Most hippocampal CA1 pyramidal cells in rabbits increase firing during awake sharp-wave ripples and some do so in response to external stimulation and theta

2020 ◽  
Vol 123 (5) ◽  
pp. 1671-1681
Author(s):  
Miriam S. Nokia ◽  
Tomi Waselius ◽  
Joonas Sahramäki ◽  
Markku Penttonen
Keyword(s):  
Eyeblink Conditioning ◽  
Cell Activity ◽  
Pyramidal Cells ◽  
External Stimulation ◽  
Ca1 Pyramidal Cells ◽  
Sharp Wave ◽  
Hippocampal Ca1 ◽  
Trace Eyeblink Conditioning ◽  
Do So

We studied hippocampal sharp-wave ripples and theta and CA1 pyramidal cell activity during trace eyeblink conditioning in rabbits. Conditioning trials suppressed ripples while increasing theta for a period of several seconds. A quarter of the cells increased firing in response to the conditioned stimulus and fired extensively during endogenous theta as well as ripples. The role of endogenous theta epochs in off-line memory consolidation should be studied further.

Coupling of cerebral blood flow to neuronal activation: role of adenosine and nitric oxide

1994 ◽  
Vol 267 (1) ◽  
pp. H296-H301 ◽  
Author(s):  
U. Dirnagl ◽  
K. Niwa ◽  
U. Lindauer ◽  
A. Villringer
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Receptor Antagonist ◽  
Barrel Cortex ◽  
No Synthase ◽  
Neuronal Activation ◽  
Whisker Stimulation ◽  
Relationship Of

We studied the role and relationship of the putative mediators of coupling of cerebral blood flow (CBF) and neuronal activation, adenosine (Ado) and nitric oxide (NO). Topical brain application over the whisker barrel cortex of anesthetized rats (n = 24) of the Ado receptor antagonist theophylline (Theo, 5 x 10(-5) M) for 30 min reduced the CBF response to deflection of the contralateral whiskers from 17.9 +/- 3.0% of baseline to 10.6 +/- 2.7% (P < 0.05). Coapplication of Theo (5 x 10(-5) M) and the NO synthase blocker N omega-nitro-L-arginine (L-NNA, 10(-3) M) for 30 min led to a further reduction in the CBF response to whisker stimulation to 7.5 +/- 1.3% (P < 0.05 compared with Theo alone). The CBF effect of sodium nitroprusside (10(-5) M) was not affected by Theo-L-NNA coapplication (122 +/- 25 vs. 140 +/- 25%, n = 5). Application of adenosine deaminase (1 U/ml, n = 5) reduced the CBF response to whisker stimulation from 18.2 +/- 0.7 to 10.7 +/- 1.9% (P < 0.05). Superfusion of L-NNA (10(-3) M, 30 min, n = 7) attenuated the CBF response to application of Ado (10(-4) M) from 39.4 +/- 10.4 to 22.9 +/- 10.5% (P < 0.05). N omega-nitro-D-arginine did not affect the CBF response to Ado (n = 5). We conclude that 1) Ado is involved in coupling of CBF to neuronal activation, 2) NO is involved in this response as well, and 3) there is an interaction between the vasodilator pathways of Ado and NO.

scholarly journals Transcranial theta-burst stimulation of primary sensory cortex attenuates somatosensory threat memory in humans

2021 ◽  
Author(s):  
Karita E Ojala ◽  
Matthias Staib ◽  
Samuel Gerster ◽  
Christian C Ruff ◽  
Dominik R Bach
Keyword(s):  
Sensory Cortex ◽  
Initial Stimulus ◽  
Non Invasive ◽  
Healthy Humans ◽  
Primary Sensory Cortex ◽  
Complex Stimuli ◽  
Sensory Cortices ◽  
Theta Burst ◽  
Stimulation Of

Sensory cortices are required for learning to discriminate complex stimuli that predict threat from those that predict safety in rodents. Yet, sensory cortices may not be needed to learn threat associations to simple stimuli. It is unknown whether these findings apply in humans. Here, we investigated the role of primary sensory cortex in discriminative threat conditioning with simple and complex somatosensory conditioned stimuli (CS) in healthy humans. Immediately before conditioning, participants received continuous theta-burst transcranial magnetic stimulation (cTBS) to primary somatosensory cortex either in the CS-contralateral or CS-ipsilateral hemisphere. After overnight consolidation, threat memory was attenuated in the contralateral compared to the ipsilateral group, as indicated by reduced startle eye-blink potentiation. There was no evidence for a difference between simple and complex stimuli, or that CS identification or conditioning was affected, suggesting a stronger effect of cTBS on consolidation than on initial stimulus processing. We propose that non-invasive stimulation of sensory cortex may provide a new avenue for interfering with threat memories in humans.

scholarly journals Modification of persistent responses in medial prefrontal cortex during learning in trace eyeblink conditioning

2014 ◽  
Vol 112 (9) ◽  
pp. 2123-2137 ◽  
Author(s):  
Jennifer J. Siegel
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Behavioral Response ◽  
Eyeblink Conditioning ◽  
Training Session ◽  
Stimulus Presentation ◽  
Response Magnitude ◽  
Learning Criterion ◽  
Initial Learning ◽  
Trace Eyeblink Conditioning

Persistent spiking in response to a discrete stimulus is considered to reflect the active maintenance of a memory for that stimulus until a behavioral response is made. This response pattern has been reported in learning paradigms that impose a temporal gap between stimulus presentation and behavioral response, including trace eyeblink conditioning. However, it is unknown whether persistent responses are acquired as a function of learning or simply represent an already existing category of response type. This fundamental question was addressed by recording single-unit activity in the medial prefrontal cortex (mPFC) of rabbits during the initial learning phase of trace eyeblink conditioning. Persistent responses to the tone conditioned stimulus were observed in the mPFC during the very first training sessions. Further analysis revealed that most cells with persistent responses showed this pattern during the very first training trial, before animals had experienced paired training. However, persistent cells showed reliable decreases in response magnitude over the first training session, which were not observed on the second day of training or for sessions in which learning criterion was met. This modification of response magnitude was specific to persistent responses and was not observed for cells showing phasic tone-evoked responses. The data suggest that persistent responses to discrete stimuli do not require learning but that the ongoing robustness of such responses over the course of training is modified as a result of experience. Putative mechanisms for this modification are discussed, including changes in cellular or network properties, neuromodulatory tone, and/or the synaptic efficacy of tone-associated inputs.

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