The Application of P300-Long-Latency Auditory-Evoked Potential in Parkinson Disease

P300 Event-Related Potential: A Surrogate Marker of Cognitive Dysfunction in Parkinson's Disease Patients with Psychosis

BACKGROUND AND OBJECTIVES

Psychosis is one of the major neuropsychiatric non-motor symptoms of Parkinson's disease (PD). Prolonged latency and decreased amplitude of the P300 event-related potential (ERP) is a potential neurophysiologic biomarker of deeper neurocognitive deficits in PD. We aimed to characterize electroencephalogram (EEG)/ERP parameters in PD patients with and without psychosis (PDP and PDNP, respectively), and to determine if such measures could act as endophenotypes for PD-associated psychosis (PDP).

METHODS

We recruited 40 PD patients (all males), 20 PDP patients and 20 PDNP patients, aged between 39 and 65 years. The cognitive composite scores for attention and working memory were calculated. EEG/ERP recording was carried out following this, with eyes-closed resting-state EEG followed by an auditory oddball P300 task.

RESULTS

The composite scores for both attention and working memory were significantly higher in the PDNP group compared to the PDP group. The mean reaction time during the oddball task in the PDP group was significantly higher than in the PDNP group. A trend of increased P300 amplitude was observed in the PDNP group compared to the PDP group; however, it was significant at CP4, P8, C4, TP8, T8, CZ, FC4, FT8, FZ, F4, and F8 electrode sites. Power spectral analysis indicated a significant increase in the EEG power of slow-frequency waves (delta, theta) across all the brain regions in the PDP group compared to the PDNP group.

CONCLUSIONS

Our results demonstrate the association between psychosis and the severity of neurocognitive deficits in PD patients assessed using electrophysiologic measures. P300 may be considered a potential neurophysiologic biomarker of psychosis in PD.

Features of attention network impairment in patients with temporal lobe epilepsy: Evidence from eye-tracking and electroencephalogram

AIM

To explore multiple features of attention impairments in patients with temporal lobe epilepsy (TLE).

METHODS

A total of 93 patients diagnosed with TLE at Xiangya Hospital during May 2022 and December 2022 and 85 healthy controls were included in this study. Participants were asked to complete neuropsychological scales and attention network test (ANT) with recording of eye-tracking and electroencephalogram.

RESULTS

All means of evaluation showed impaired attention functions in TLE patients. ANT results showed impaired orienting (p < 0.001) and executive control (p = 0.041) networks. Longer mean first saccade time (p = 0.046) and more total saccadic counts (p = 0.035) were found in eye-tracking results, indicating abnormal alerting and orienting networks. Both alerting, orienting and executive control networks were abnormal, manifesting as decreased amplitudes (N1 & P3, p < 0.001) and extended latency (P3, p = 0.002). The energy of theta, alpha and beta were all sensitive to the changes of alerting and executive control network with time, but only beta power was sensitive to the changes of orienting network.

CONCLUSION

Our findings are helpful for early identification of patients with TLE combined with attention impairments, which have strong clinical guiding significance for long-term monitoring and intervention.

Upregulation of p300 in paclitaxel-resistant TNBC: implications for cell proliferation via the PCK1/AMPK axis

OBJECTIVE

To explore the role of p300 in the context of paclitaxel (PTX) resistance in triple-negative breast cancer (TNBC) cells, focusing on its interaction with the phosphoenolpyruvate carboxykinase 1 (PCK1)/adenosine monophosphate-activated protein kinase (AMPK) pathway.

METHODS

The expression of p300 and PCK1 at the messenger ribonucleic acid (mRNA) level was detected using a quantitative polymerase chain reaction. The GeneCards and GEPIA databases were used to investigate the relationship between p300 and PCK1. The MDA-MB-231/PTX cell line, known for its PTX resistance, was chosen to understand the specific role of p300 in such cells. The Lipofectamine™ 3000 reagent was used to transfer the p300 small interfering RNA and the overexpression of PCK1 plasmid into MDA-MB-231/PTX. The expression levels of p300, PCK1, 5'AMPK and phosphorylated AMPK (p-AMPK) were determined using the western blot test.

RESULTS

In TNBC cancer tissue, the expression of p300 was increased compared with TNBC paracancerous tissue (P < 0.05). In the MDA-MB-231 cell line of TNBC, the expression of p300 was lower than in the PTX-resistant TNBC cells (MDA-MB-231/PTX) (P < 0.05). The PCK1 expression was decreased in the TNBC cancer tissue compared with TNBC paracancerous tissue, and the PCK1 expression was reduced in MDA-MB-231/PTX than in MDA-MB-231 (P < 0.05) indicating that PCK1 was involved in the resistance function. Additionally, p-AMPK was decreased in MDA-MB-231/PTX compared with MDA-MB-231 (P < 0.05). The adenosine triphosphate (ATP) level was also detected and was significantly lower in MDA-MB-231/PTX than in MDA-MB-231 (P < 0.05). Additionally, cell proliferation increased significantly in MDA-MB-231/PTX at 48 and 72 h (P < 0.05) suggesting that MDA-MB-231/PTX cells obtained the resistance function which was associated with AMPK and ATP level. When p300 was inhibited, p-AMPK and ATP levels elevated in MDA-MB-231/PTX (P < 0.05). When PCK1 was suppressed, the ATP consumption rate decreased, and cell proliferation increased (P < 0.05). However, there were no changes in p300.

CONCLUSIONS

In MDA-MB-231/PTX, p300 can inhibit p-AMPK and ATP levels by inhibiting PCK1 expression. Our findings suggest that targeting p300 could modulate the PCK1/AMPK axis, offering a potential therapeutic avenue for overcoming PTX resistance in TNBC.

Electrophysiological Testing for an Auditory Processing Disorder and Reading Performance in 54 School Students Aged Between 8 and 12 years

BACKGROUND Learning to read and write depends on the effective functioning of various sensory systems, including the auditory system. Auditory information processing involves behavioral and electrophysiological processes. Electrophysiological procedures are used to investigate activity in the auditory pathway in response to sound stimuli, and the associated cortical activity in discrimination, integration, and attention. The study evaluated electrophysiological testing for an auditory processing disorder and reading performance in 54 school students aged between 8 and 12 years. MATERIAL AND METHODS The study involved 54 public school students aged between 8 and 12 years, who were divided into a study group and control group. All children underwent basic audiological assessment, rating of reading and writing ability, non-verbal intelligence, auditory brainstem response, long-latency auditory-evoked potentials (LLAEP), frequency following responses (FFR), and auditory training (AT). RESULTS The basic audiological evaluation showed a statistically significant difference between groups only for the frequency of 6 kHz. The LLAEP response had a statistically significant difference between groups for N1 latency, P300 latency, and amplitude. Finally, there was a statistically significant difference between pre-AT and post-AT to LLAEP for latencies of P2, N2, and P300 and amplitudes of N2 and P300, and to FFR for latency of wave C. CONCLUSIONS This study showed that electrophysiological tests are sensitive tools for identifying deficits in the auditory pathway. Moreover, latency measures can detect improvements from an auditory training program. In this way, an auditory intervention program might help children with reading and writing difficulties.

Breaching Subjects' Thoughts Privacy: A Study with Visual Stimuli and Brain-Computer Interfaces

Brain-computer interfaces (BCIs) started being used in clinical scenarios, reaching nowadays new fields such as entertainment or learning. Using BCIs, neuronal activity can be monitored for various purposes, with the study of the central nervous system response to certain stimuli being one of them, being the case of evoked potentials. However, due to the sensitivity of these data, the transmissions must be protected, with blockchain being an interesting approach to ensure the integrity of the data. This work focuses on the visual sense, and its relationship with the P300 evoked potential, where several open challenges related to the privacy of subjects' information and thoughts appear when using BCI. The first and most important challenge is whether it would be possible to extract sensitive information from evoked potentials. This aspect becomes even more challenging and dangerous if the stimuli are generated when the subject is not aware or conscious that they have occurred. There is an important gap in this regard in the literature, with only one work existing dealing with subliminal stimuli and BCI and having an unclear methodology and experiment setup. As a contribution of this paper, a series of experiments, five in total, have been created to study the impact of visual stimuli on the brain tangibly. These experiments have been applied to a heterogeneous group of ten subjects. The experiments show familiar visual stimuli and gradually reduce the sampling time of known images, from supraliminal to subliminal. The study showed that supraliminal visual stimuli produced P300 potentials about 50% of the time on average across all subjects. Reducing the sample time between images degraded the attack, while the impact of subliminal stimuli was not confirmed. Additionally, younger subjects generally presented a shorter response latency. This work corroborates that subjects' sensitive data can be extracted using visual stimuli and P300.