Human functional MRI studies in acute and various chronic pain conditions have revolutionized how we view pain, and have led to a new theory that complex multi-dimensional pain experience (sensory-discriminative, affective/motivational, and cognitive) is represented by concurrent activity in widely-distributed brain regions (termed a network or pain matrix). Despite these breakthrough discoveries, the specific functions proposed for these regions remain elusive, because detailed electrophysiological characterizations of these regions in the primate brain are lacking. To fill in this knowledge gap, we have studied the cortical areas around the central and lateral sulci of the non-human primate brain with combined submillimeter resolution functional imaging (optical imaging and fMRI) and intracranial electrophysiological recording. In this mini-review, I summarize and present data showing that the cortical circuitry engaged in nociceptive processing is much more complex than previously recognized. Electrophysiological evidence supports the engagement of a distinct nociceptive-processing network within SI (i.e., areas 3a, 3b, 1 and 2), SII, and other areas along the lateral sulcus. Deafferentation caused by spinal cord injury profoundly alters the relationships between fMRI and electrophysiological signals. This finding has significant implications for using fMRI to study chronic pain conditions involving deafferentation in humans.
Animals ; Cerebral Cortex ; diagnostic imaging ; physiopathology ; Humans ; Pain ; diagnostic imaging ; pathology ; physiopathology ; Primates ; Touch ; physiology

Animals ; Brain Chemistry ; Brain Ischemia ; metabolism ; physiopathology ; Cerebral Cortex ; metabolism ; Dementia ; metabolism ; physiopathology ; Humans ; Microdialysis ; Reperfusion Injury ; metabolism ; physiopathology

OBJECTIVETo access the pathological changes of the functional localization of the primary auditory cortex in auditory neuropathy patients using magnetoencephalography (MEG).

METHODSThe M100 waves of cortical evoked magnetic fields (AEF) evoked by 0.5, 1, 2, 4, 6, 8 kHz pure tones were measured respectively in 10 auditory neuropathy patients (20 ears) and 15 healthy young subjects (30 ears) using a whole head 306 channel magnetoencephalography (MEG) system. The auditory cortex magnetic source imaging obtained by superimposing functional MEG data on structural magnetic resonance image (MRI).

RESULTSThe M100 sources were obtained in all 15 healthy young subjects in all frequency except for 8 kHz in 16 ears. But in auditory neuropathy patients, the ratio of M100 from 0.5 to 6 kHz were 27.5% (11/40), 22.5% (9/40), 7.5% (3/40), 5% (2/40), 5% (2/40) respectively and no any waves in 8 kHz. The evoked ratio of M100 in low frequency was high and that decreased gradually with increasing of evoked pure tone frequency. The M100 latentencies and amplitudes were longer and lower in patient group than that in control group (P < 0.01).

CONCLUSIONSAuditory neuropathy is an audiology disease with pathological lesions from the VIII cranial nerve to auditory cortex. MEG might become an important reference in decision making for therapies.

Adolescent ; Auditory Cortex ; pathology ; physiopathology ; Case-Control Studies ; Cerebral Cortex ; pathology ; physiopathology ; Evoked Potentials, Auditory ; Female ; Humans ; Magnetoencephalography ; Male ; Vestibulocochlear Nerve Diseases ; pathology ; physiopathology ; Young Adult

Acute pain is a warning protective sensation for any impending harm. However, chronic pain syndromes are often resistant diseases that may consume large amount of health care costs. It has been suggested by recent studies that pain perception may be formed in central neural networks via large-scale coding processes, which involves sensory, affective, and cognitive dimensions. Many central areas are involved in these processes, including structures from the spinal cord, the brain stem, the limbic system, to the cortices. Thus, chronic painful diseases may be the result of some abnormal coding within this network. A thorough investigation of coding mechanism of pain within the central neuromatrix will bring us great insight into the mechanisms responsible for the development of chronic pain, hence leading to novel therapeutic interventions for pain management.
Animals ; Cerebral Cortex ; physiology ; Humans ; Nociception ; physiology ; Pain ; physiopathology ; Thalamus ; physiology

The purpose of this study is to delineate the pattern of reorganization of cortical language areas using functional magnetic resonance imaging (fMRI) after rehabilitation therapy in patients with aphasia. Six right-handed aphasic patients were investigated. Causes of aphasia were intracerebral hemorrhages of the left basal ganglia in 3 patients, cerebral infarction of the left MCA in 2, and surgical resection of the frontotemporal lobes to control intractable epilepsy in 1. An auditory sentence completion task was used to activate brain language areas during the fMRI. Three patients with left frontal lesions showed activation in the right inferior frontal lobes while performing language tasks, whereas the other 3, whose lesions located at subcortical areas, showed activation in the bilateral frontal and temporal lobes. Our results demonstrated the differences in interhemispheric reorganization of the language network depending on the location of the lesion in aphasic patients. While the patients with subcortical lesion showed tendency of bilateral frontal activation, those with cortical lesion showed activation of the right frontal lobe.
Adult ; Aphasia/*pathology/physiopathology ; Cerebral Cortex/*pathology ; Female ; Human ; *Language ; Magnetic Resonance Imaging ; Male ; Middle Age

OBJECTIVE: To investigate the changes in gray matter volume in depressive-like mice and explore the possible mechanism. METHODS: Twenty-four 6-week-old C57 mice were randomized equally into control group and model group, and the mice in the model group were subjected to chronic unpredictable mild stimulation (CUMS) for 35 days. Magnetic resonance imaging was performed to examine structural changes of the grey matter volume in depressive-like mice. The expression of brain-derived neurotrophic factor (BDNF) in the grey matter of the mice was detected using Western blotting and immunofluorescence staining. RESULTS: Compared with the control mice, the mice with CUMS showed significantly decreased central walking distance in the open field test (P < 0.05) and increased immobile time in forced swimming test (P < 0.05). Magnetic resonance imaging showed that the volume of the frontal cortex was significantly decreased in CUMS mice (P < 0.001, when the mass level was greater than or equal to 10 756, the FDRc was corrected with P=0.05). Western blotting showed that the expression of mature BDNF in the frontal cortex was significantly decreased in CUMS mice (P < 0.05), and its expression began to decrease after the exposure to CUMS as shown by immunofluorescence staining. The volume of different clusters obtained by voxel-based morphometry (VBM) analysis was correlated with the expression level of mature BDNF detected by Western blotting (P < 0.05). CONCLUSION The decrease of frontal cortex volume after CUMS is related with the reduction of mature BDNF expression in the frontal cortex.
Animals ; Mice ; Blotting, Western ; Brain-Derived Neurotrophic Factor ; Cerebral Cortex ; Depression/physiopathology* ; Frontal Lobe/pathology*

OBJECTIVETo investigate the clinical symptoms and features of interictal epileptiform discharges (IED) on electroencephalogram (EEG) in children with spastic hemiplegic cerebral palsy (CP) and to analyze the risk factors for IED.

METHODSEighty-three children with spastic hemiplegic CP were recruited, and their clinical data, results of video-electroencephalogram, imaging findings, and cognitive levels were collected. The influencing factors for IED were determined by multiple logistic regression analysis.

RESULTSThe incidence of epilepsy was 13% in children with spastic hemiplegic CP; 34% of these cases had IED. The incidence of epilepsy in children with IED (32%) was significantly higher than that in those without IED (4%) (P<0.01). The incidence of IED in children with complications and brain cortex impairment increased significantly (P<0.01). The incidence of IED varied significantly between patients with different cognitive levels (P<0.01). Brain cortex impairment (OR=11.521) and low cognitive level (OR=2.238)were risk factors for IED in children with spastic hemiplegic CP (P<0.05).

CONCLUSIONSSpastic hemiplegic CP is often found with IED on EEG, and the incidence of epilepsy is higher in children with IED than in those without IED. Brain cortex impairment and low cognitive level have predictive values for IED in children with spastic hemiplegic CP.

Cerebral Cortex ; physiopathology ; Cerebral Palsy ; physiopathology ; Child ; Child, Preschool ; Electroencephalography ; Epilepsy ; epidemiology ; etiology ; Female ; Hemiplegia ; physiopathology ; Humans ; Incidence ; Infant ; Male ; Risk Factors

Epilepsy is a common neurological disease accompanied with laden economic burdens and heavy social resources consuming. Temporal lobe epilepsy (TLE) is an important subtype of the epilepsies. Our experiment was aimed to characterize the regional brain function alteration among the treatment na? ve TLE patients using ReHo. We found that elevated regional ReHo was in the left insula in the TLE patients, and the right one was cingulated, while the decreasing ReHo was in right putamen. Our result demonstrated that the key components associated with the epilepsy symptoms had altered the regional function in the TLE patients, and the disruption of cortex-thalamus-striatum loop. Our experiment provides evidence on the pathophysiological alteration in treatment na? ve TLE patients.
Adult ; Brain ; physiopathology ; Cerebral Cortex ; physiopathology ; Depression ; physiopathology ; Epilepsy, Temporal Lobe ; physiopathology ; Female ; Gyrus Cinguli ; physiopathology ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Signal Processing, Computer-Assisted

To investigate inter- and intra-hemispheric electroencephalography (EEG) coherence at rest and during photic stimulation of patients with Alzheimer's disease (AD). Thirty-five patients (12 males, 23 females; 52 to approximately 64 y) and 33 sex- and age-matched controls (12 males, 21 females; 56 to approximately 65 y) were recruited in the present study. EEG signals from C3-C4, P3-P4, T5-T6 and O1-O2 electrode pairs resulted from the inter-hemispheric action, and EEG signals from C3-P3, C4-P4, P3-O1, P4-O2, C3-O1, C4-O2, T5-O1 and T6-O2 electrode pairs resulted from the intra-hemispheric action. The influence of inter- and intra-hemispheric coherence on EEG activity with eyes closed was examined, using fast Fourier transformation from the 16 sampled channels. The frequencies of photic stimulation were fixed at 5, 10 and 15 Hz, respectively. The general decrease of AD patients in inter- and intra-hemispheric EEG coherence was more significant than that of the normal controls at the resting EEG, with most striking decrease observed in the alpha-1 (8.0-9.0 Hz) and alpha-2 (9.5-12.5 Hz) bands. During photic stimulation, inter- and intra-hemispheric EEG coherences of the AD patients having lower values in the alpha (9.5-10.5 Hz) band than those of the control group. It suggests that under stimulated and non-stimulated conditions, AD patients had impaired inter- and intra-hemispheric functional connections, indicating failure of brain activation in alpha-related frequency.
Alzheimer Disease ; diagnosis ; physiopathology ; Case-Control Studies ; Cerebral Cortex ; physiopathology ; Electrodes ; Electroencephalography ; Female ; Humans ; Male ; Middle Aged

This experimental study was aimed to evaluate the injurious effects of chronic traumatic brain injury on cortex mitochondrial function in rats. The head of rat was impacted by a metal sphere in a weight-drop device twice per day for 30 days, cortex mitochondria were isolated. Then the mitochondria membrane fluidity, swelling, respiratory function, the activities of mitochondria respiratory enzymes and superoxide dismutase (SOD), the levels of phospholipid, malondial dehyde (MDA) and Ca2+ were determined to analyze the function of mitochondria. The data indicated that chronic closed traumatic brain injury caused severe neuronal mitochondrial injuries. The swelling of mitochondria was aggravated, the decomposability of mitochondrial membrane phospholipid was increased, the membrane fluidity of mitochondria was decreased; the chronic closed traumatic brain injury also significantly depressed the activities of respiratory enzymes and SOD of mitochondria, increased the level of MDA and Ca2+. The chronic closed traumatic brain injury induced damage to rat cortex mitochondria. The mechanisms may be derived from the secondary increase of free radicals induced by mitochondrial membrane injury and the obstacle of rat brain energy metabolism.
Animals ; Brain Injury, Chronic ; pathology ; physiopathology ; Cerebral Cortex ; pathology ; physiopathology ; Male ; Mitochondria ; pathology ; physiology ; Random Allocation ; Rats ; Rats, Sprague-Dawley