Even though retinal images of objects change their locations following each eye movement, we perceive a stable and continuous world. One possible mechanism by which the brain achieves such visual stability is to construct a craniotopic coordinate by integrating retinal and extraretinal information. There have been several proposals on how this may be done, including eye-position modulation (gain fields) of retinotopic receptive fields (RFs) and craniotopic RFs. In the present study, we investigated coordinate systems used by RFs in the lateral intraparietal (LIP) cortex and frontal eye fields (FEF) and compared the two areas. We mapped the two-dimensional RFs of neurons in detail under two eye fixations and analyzed how the RF of a given neuron changes with eye position to determine its coordinate representation. The same recording and analysis procedures were applied to the two brain areas. We found that, in both areas, RFs were distributed from retinotopic to craniotopic representations. There was no significant difference between the distributions in the LIP and FEF. Only a small fraction of neurons was fully craniotopic, whereas most neurons were between the retinotopic and craniotopic representations. The distributions were strongly biased toward the retinotopic side but with significant craniotopic shifts. These results suggest that there is only weak evidence for craniotopic RFs in the LIP and FEF, and that transformation from retinotopic to craniotopic coordinates in these areas must rely on other factors such as gain fields.
Animals ; Macaca ; Visual Fields ; Frontal Lobe/physiology* ; Eye Movements ; Brain

Active exploratory behaviors have often been associated with theta oscillations in rodents, while theta oscillations during active exploration in non-human primates are still not well understood. We recorded neural activities in the frontal eye field (FEF) and V4 simultaneously when monkeys performed a free-gaze visual search task. Saccades were strongly phase-locked to theta oscillations of V4 and FEF local field potentials, and the phase-locking was dependent on saccade direction. The spiking probability of V4 and FEF units was significantly modulated by the theta phase in addition to the time-locked modulation associated with the evoked response. V4 and FEF units showed significantly stronger responses following saccades initiated at their preferred phases. Granger causality and ridge regression analysis showed modulatory effects of theta oscillations on saccade timing. Together, our study suggests phase-locking of saccades to the theta modulation of neural activity in visual and oculomotor cortical areas, in addition to the theta phase locking caused by saccade-triggered responses.
Animals ; Frontal Lobe/physiology* ; Macaca mulatta ; Neurons/physiology* ; Saccades ; Theta Rhythm ; Visual Fields

Epilepsy is a chronic neurological disorder, which is not only related to the imbalance between excitatory glutamic neurons and inhibitory GABAergic neurons, but also related to abnormal central cholinergic regulation. This article summarizes the scientific background and experimental data about cholinergic dysfunction in epilepsy from both cellular and network levels, further discusses the exact role of cholinergic system in epilepsy. In the cellular level, several types of epilepsy are believed to be associated with aberrant metabotropic muscarinic receptors in several different brain areas, while the mutations of ionotropic nicotinic receptors have been reported to result in a specific type of epilepsy-autosomal dominant nocturnal frontal lobe epilepsy. In the network level, cholinergic projection neurons as well as their interaction with other neurons may regulate the development of epilepsy, especially the cholinergic circuit from basal forebrain to hippocampus, while cholinergic local interneurons have not been reported to be associated with epilepsy. With the development of optogenetics and other techniques, dissect and regulate cholinergic related epilepsy circuit has become a hotspot of epilepsy research.
Acetylcholine ; physiology ; Basal Forebrain ; pathology ; Brain Chemistry ; genetics ; physiology ; Cholinergic Neurons ; chemistry ; classification ; pathology ; physiology ; Epilepsy ; genetics ; pathology ; physiopathology ; Epilepsy, Frontal Lobe ; genetics ; GABAergic Neurons ; physiology ; Hippocampus ; pathology ; Humans ; Mutation ; genetics ; physiology ; Neurons ; Non-Neuronal Cholinergic System ; genetics ; physiology ; Receptors, Muscarinic ; genetics ; physiology ; Receptors, Nicotinic ; genetics ; physiology ; Synaptic Transmission ; genetics ; physiology

BACKGROUNDAmyloid β (Aβ) deposits and the endoplasmic reticulum stress (ERS) are both well established in the development and progression of Alzheimer's disease (AD). However, the mechanism and role of Aβ-induced ERS in AD-associated pathological progression remain to be elucidated.

METHODSThe five familial AD (5×FAD) mice and wild-type (WT) mice aged 2, 7, and 12 months were used in the present study. Morris water maze test was used to evaluate their cognitive performance. Immunofluorescence and Western blot analyses were used to examine the dynamic changes of pro-apoptotic (CCAAT/enhancer-binding protein homologous protein [CHOP] and cleaved caspase-12) and anti-apoptotic factors (chaperone glucose-regulated protein [GRP] 78 and endoplasmic reticulum-associated protein degradation-associated ubiquitin ligase synovial apoptosis inhibitor 1 [SYVN1]) in the ERS-associated unfolded protein response (UPR) pathway.

RESULTSCompared with age-matched WT mice, 5×FAD mice showed higher cleaved caspase-3, lower neuron-positive staining at the age of 12 months, but earlier cognitive deficit at the age of 7 months (all P < 0.05). Interestingly, for 2-month-old 5×FAD mice, the related proteins involved in the ERS-associated UPR pathway, including CHOP, cleaved caspase-12, GRP 78, and SYVN1, were significantly increased when compared with those in age-matched WT mice (all P < 0.05). Moreover, ERS occurred mainly in neurons, not in astrocytes.

CONCLUSIONSThese findings suggest that compared with those of age-matched WT mice, ERS-associated pro-apoptotic and anti-apoptotic proteins are upregulated in 2-month-old 5×FAD mice, consistent with intracellular Aβ aggregation in neurons.

Alzheimer Disease ; metabolism ; Amyloid beta-Peptides ; metabolism ; Animals ; Apoptosis ; physiology ; Blotting, Western ; Caspase 12 ; metabolism ; Endoplasmic Reticulum Stress ; physiology ; Frontal Lobe ; metabolism ; Heat-Shock Proteins ; metabolism ; Immunohistochemistry ; Mice ; Mice, Transgenic ; Neurons ; metabolism ; Transcription Factor CHOP ; metabolism ; Ubiquitin-Protein Ligases ; metabolism ; Unfolded Protein Response ; physiology

OBJECTIVETo explore the influence of verbal working memory load on associative neural networks.

METHODSTwenty-one subjects were required to complete a verbal delayed matching-to-sample task under the condition of low (3 items) or high (5 items) working memory load (WML). The 19-channels event-related potentials (ERP) were analyzed with statistical parametric mapping.

RESULTSA significant difference in working memory capacity (WMC) was found between low WML and high WML groups [2.48∓0.30 vs 3.30∓0.76; t(20)=5.950, P=0.000]. Statistical parametric mapping revealed that during the encoding stage, the effects of WML appeared in succession in the right ventral attention network (rVAN), the dorsal attention network, and the language areas in the left hemisprere. During the maintenance stage, the effects WML occured in the rVAN acompanied by either DAN or left frontal-temporal regions. CONCLUSIONS;onclusions When the WML is beyond the WMC, the rVAN may participate in the prevention of interference among items and in the activation of long-term memory.

Attention ; Evoked Potentials ; Frontal Lobe ; physiology ; Humans ; Memory, Short-Term ; Spatio-Temporal Analysis

This study sought to reveal the difference of brain functions at resting-state between subjects with sub-health and normal controls by using the functional magnetic resonance imaging (fMRI) technology. Resting-state fMRI scans were performed on 24 subjects of sub-health and on 24 healthy controls with gender, age and education matched with the sub-health persons. Compared to the healthy controls, the sub-health group showed significantly higher regional homogeneity (ReHo) in the left post-central gyrus and the right post-central gyrus. On the other hand, the sub-health group showed significantly lower ReHo in the left superior frontal gyrus, in the right anterior cingulated cortex and ventra anterior cingulate gyrus, in the left dorsolateral frontal gyrus, and in the right middle temporal gyrus. The Significant difference in ReHo suggests that the sub-health persons have abnormalities in certain brain regions. It is proved that its specific action and meaning deserves further assessment.
Brain ; physiology ; physiopathology ; Brain Mapping ; Case-Control Studies ; Cerebral Cortex ; Frontal Lobe ; Gyrus Cinguli ; Humans ; Magnetic Resonance Imaging ; Parietal Lobe

To explore the relationship between the drug-seeking behavior, motivation of conditioned place preference (CPP) rats and the frontal association cortex (FrA) electroencephalogram (EEG) sample entropy, we in this paper present our studies on the FrA EEG sample entropy of control group rats and CPP group rats, respectively. We invested different behavior in four situations of the rat activities, i. e. rats were staying in black chamber of videoed boxes, those staying in white chamber of videoed boxes, those shuttling between black-white chambers and those shuttling between white-black chambers. The experimental results showed that, compared with the control group rats, the FrA EEG sample entropy of CPP rats staying in black chamber of video box and shuttling between white-black chambers had no significant difference. However, sample entropy is significantly smaller (P < 0.01) when heroin-induced group rats stayed in white chamber of video box and shuttled between black-white chambers. Consequently, the drug-seeking behavior and motivation of CPP rats correlated closely with the EEG sample entropy changes.
Animals ; Conditioning (Psychology) ; drug effects ; Drug-Seeking Behavior ; Electroencephalography ; Entropy ; Frontal Lobe ; drug effects ; physiology ; Heroin ; pharmacology ; Rats ; Rats, Sprague-Dawley

The present study investigated the characteristic of semantic cognition of Uyghur-Chinese bilinguals. The event-related potentials (ERP) technique was used to explore the characteristic of N400 wave and topographic map of difference-waves with "picture-word" semantic priming paradigm. There were significant semantic priming effects on two languages. The average amplitude of N400 was similar in two languages, while average amplitudes of three electrodes (F3, F4, PZ) in Chinese were negative than others. Meanwhile, the activation of topographic map of Uyghur was almost in all regions except occipital lobe, and the degree of activation of Chinese was less than Uyghur, but the activation in parietal and bilateral frontal lobes was higher. In conclusion, the present study suggests that two languages of Uyghur-Chinese bilinguals are all sensitive to semantic priming. The bilateral frontal and parietal lobes participate in language switching. Semantic cognition of two languages in Uyghur-Chinese late non-proficient bilinguals is both completed by bilateral cerebral hemispheres. We have not found obvious lateralization on two languages of Uyghur-Chinese bilinguals.
Asian Continental Ancestry Group ; China ; Cognition ; Evoked Potentials ; Frontal Lobe ; physiology ; Humans ; Language ; Parietal Lobe ; physiology ; Semantics

OBJECTIVETo explore the working mechanism and age-related change of the conflict processing system of the frontal cortex.

METHODSFifteen normal elderly people and 15 youth were performed a modified Eriksen flanker paradigm, while event-related potential (ERPs), which include 32 systerm electroencephalography, reaction time and correct rate were recorded.

RESULTSThe elderly group showed a distinct effect of reaction time and effect of conflict in the respond level compared with the youth group. The elderly group had a longer time window of N380 and same amplitude as the youth group. Low resolution brain electromagnetic tomography (LORETA) showed the bilateral temporal lobe and the dorsolateral prefrontal cortex (especially right) were activated in the youth group, while the left temporal lobe, the left dorsolateral prefrontal cortex and left medial frontal gyrus were activated in the elderly group.

CONCLUSIONWhen conflict stimuli existed in the response level, old people showed frontal interference control hypofunction. N380 reflected the activation of the left dorsolateral prefrontal cortex and the left temporal lobe during response selection and executive control processing in older people.

Adolescent ; Aged ; Aging ; Electroencephalography ; Evoked Potentials ; Frontal Lobe ; physiology ; Humans ; Prefrontal Cortex ; physiology ; Reaction Time ; Temporal Lobe ; physiology

OBJECTIVETo observe the effect of acupuncture at the whole points of Hand Jueyin pericardium meridian on the amplitude of low frequency fluctuations (ALFF) of healthy people in resting state (R1) functional magnetic resonance imaging (fMRI).

METHODSTotally 16 healthy subjects received structure scan of T1 and T2. Then two fMRI scans were conducted for each participant. fMRI included the resting-state scan (R1; the scanning time was 8 min 6 s), the stimulating-acupoint scan (AP; the scanning time was 8 min 6 s). fMRI data acquisition from structure scanning and function scanning were processed with format conversion and statistical analysis.

RESULTSUnder R1 state, brain regions with activated ALFF signals included bilateral superior frontal gyrus, medial frontal gyrus, middle occipital gyrus, precuneus, superior temporal gyrus, and cingulate gyrus. Under the AP state, brain regions with activated ALFF signals were bilateral superior frontal gyrus, medial frontal gyrus, middle temporal gyrus, left fusiform gyrus, precuneus, posterior cingulate, and declivis. Compared with R1 state, obvious difference of ALFF signal areas of the brain caused by acupuncture at pericardium were: bilateral cuneus, precuneus, left posterior cingulate gyrus, right middle occipital gyrus, and right occipital lingual gyrus.

CONCLUSIONAcupuncture at the whole points of Hand Jueyin pericardium meridian could significantly change inherent activity states of the cerebral cortex, especially in bilateral superior frontal gyrus, medial frontal gyrus, and precuneus.

Acupuncture ; Acupuncture Points ; Brain ; physiology ; Brain Mapping ; Frontal Lobe ; Humans ; Magnetic Resonance Imaging ; methods ; Pericardium