Slow and Fast (Gamma) Neuronal Oscillations in the Perirhinal Cortex and Lateral Amygdala
Bibliographic record
Abstract
Most lesion studies emphasize the distinct contributions of the amygdala and perirhinal cortex to memory. Yet, the presence of strong reciprocal excitatory projections between these two structures suggests that they are functionally coupled. To gain some insight into this issue, the present study examined whether the close anatomical ties existing between perirhinal and lateral amygdala (LA) neurons are expressed in their spontaneous activity. To this end, multiple simultaneous recordings of single unit discharges and local field potentials were performed in the LA and perirhinal cortex in ketamine-xylazine anesthetized cats. The perirhinal cortex and LA exhibited a similar pattern of spontaneous activity. Recordings at both sites were dominated by a slow focal oscillation at 1 Hz onto which was superimposed a faster rhythm (approximately 30 Hz) whose amplitude fluctuated cyclically. Computing crosscorrelograms between focal waves recorded simultaneously in the perirhinal cortex and LA revealed a close relationship between their spontaneous activity. Even when recording sites were separated by as much as 8 mm, the slow focal oscillation remained highly correlated (r > or = 0.7). In contrast, the correlation between fast oscillations was usually lower (r approximately 0.3). Perievent histograms of neuronal discharges revealed that the firing probability of most LA and perirhinal neurons increased during the depth-negative component of the slow oscillation. In addition, respectively, 47 and 64% of LA and perirhinal neurons exhibited a significant modulation of firing probability in relation to the fast oscillations. Finally, crosscorrelating unit discharges simultaneously recorded in the LA and perirhinal cortex confirmed the presence of phase-related oscillatory events in both structures. In summary, our results suggest that the interconnections existing between the perirhinal cortex and LA can support the genesis of coherent neuronal activities at various frequencies. These results imply that cooperative interactions must be taking place between these structures.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".