Nitric oxide is synthesized by cells containing the nitric oxide synthase (NOS), and NADPH-diaphorase (NADPH-d) is a selective histochemical marker for the NOS in the brain. The influence of feeding rats only half the amount of their normal daily intake of a purified diet on NOS was measured in the cerebral cortex by immunohistochemistry and NADPH-d histochemistry. iNOS was not detected in the cerebral cortex of control group. iNOS-positive neurons were induced in the cerebral cortex at 1 week after food restriction and found in specific cortical areas, such as primary motor cortex, secondary motor cortex, primary somatosensory cortex, secondary somatosensory cortex, parietal association cortex, auditory cortex, visual cortex, temporal association cortex and retrosplenial cortex. At 2 weeks after food restriction, iNOS-positive neurons were not found in all cortical areas. At 4 weeks after food restriction, iNOS-positive neurons were found in ectorhinal cortex and perirhinal cortex. In samples obtained 3 days after food restriction, the staining intensity of NADPH-d-positive neurons was decreased in most cortrical regions compared to the control group. At 1 week after food restriction, the staining intensity of NADPH-d was significantly increased in isocortical regions compared to the control group. At 9 weeks after food restriction, the staining intensity of NADPH-d was significantly decreased in all cortical regions. NO, a free radical synthesized in the brain by NOS, is a messenger molecule that mediates vascular dilatation and neural transmission. Therefore, neurons showing induced iNOS-positivity and upregulated NADPH-d-positive neurons may affect the neuronal activity in the cerebral cortex after food restriction.
Animals ; Auditory Cortex ; Brain ; Cerebral Cortex* ; Diet ; Dilatation ; Immunohistochemistry ; Motor Cortex ; Neurons* ; Nitric Oxide Synthase ; Nitric Oxide* ; Rabeprazole ; Rats* ; Somatosensory Cortex ; Synaptic Transmission ; Visual Cortex

Administration of kainate (KA) results in the induction of epileptiform activity and limbic motor seizures. Nitric oxide (NO) is a gaseous messenger that plays a role in neural transmission, long term potentiation, depression and cerebral blood flow. NO is formed by NO synthase (NOS) from arginine. NO mediates the increase in cerebral blood flow during seizure activity. However, the production site of NO has not been clearly defined. Recent report showed that constitutive NOS may be induced under certain conditions. Therefore, the present study was aimed to investigate the change of NOS and calbindin D28k in the rat cerebral cortex following seizure. Rats were injected with KA and killed at 6 hours, 1, 3, 6 and 12 days after seizure. Expressional change of nNOS and calbindin D28k was assessed by histochemistry, immunohistochemistry and RT-PCR in the rat brain. Induced NADPH-d positive neurons were observed in the cerebral cortex of 1, 3, 6 and 12 days after seizure and found in specific cortical areas, such as motor cortex, somatosensory cortex, auditory cortex, visual cortex, ectorhinal cortex and perirhinal cortex. The level of nNOS mRNA increased at 1, 3, 6 and 12 days after seizure compared with control group. Induced calbindin D28k positive neurons were observed in motor cortex and somatosensory cortex 1 and 3 days after seizure. The level of calbindin D28k mRNA in the cerebral cortex was slightly decreased at 1 day after seizure. Therefore, in this study, the induced NADPH-d, calbindin D28k positive neurons and upregulated NADPH-d positive neurons may influence the cerebral blood flow and neuronal activity in the cerebral cortex during post-seizure period.
Animals ; Arginine ; Auditory Cortex ; Brain ; Calbindin 1* ; Calbindins* ; Cerebral Cortex* ; Depression ; Immunohistochemistry ; Kainic Acid ; Long-Term Potentiation ; Motor Cortex ; Neurons* ; Nitric Oxide ; Nitric Oxide Synthase ; Rats* ; RNA, Messenger ; Seizures ; Somatosensory Cortex ; Synaptic Transmission ; Visual Cortex

This study was aimed to clarify the change of neuropeptide Y -immunoreactive (NPY -IR) and NADPH -diaphorase (NADPH -d)-positive neurons associated with aging of ICR and C57Bl/6 mice. To verify the effect of aging on NPY and NADPH -d neurons in the cerebral cortex, the tissues were stained by the immunohistochemical and histochemical method. The coexistence of NADPH -d and NPY was found in the cerebral cortex of the ICR and C57Bl/6 mice. The 30 -week -old ICR mice showed a significant increase in the number of NPY - IR neurons in comparison with the 5 -week -old mice in primary motor, secondary somatosensory, ectorhinal, auditory and visual cortex. In the 30 -week -old C57Bl/6 mice, the number of NPY -IR neurons was significantly increased in primary and secondary somatosensory cortex, decreased in retrosplenial and visual cortex compared to the 5 -week -old group. However, the number of NPY -IR/NADPH -d positive neurons of ICR mice was no significant changes in most cerebral cortical areas except insular and perirhinal cortex in the 30 week -old group in comparison with 5 -week -old group of both mice group. The number of coexisted neurons of 30 -week -old C57Bl/6 mice was significantly decreased in primary motor and auditory cortex compared to the 5 -week - old group. These results provides the morphological evidence for the change of NPY -IR neurons that do not contain NADPH -d may be more susceptible to age -related change than NADPH -d -containing neurons in the cerebral cortex of mice.
Aging ; Animals ; Auditory Cortex ; Cerebral Cortex* ; Mice* ; Mice, Inbred ICR ; NADP ; Neurons* ; Neuropeptide Y ; Neuropeptides* ; Somatosensory Cortex ; Visual Cortex

Administration of kainic acid (KA) results in induction of epileptiform activity and motor seizures. Nitric oxide (NO) mediates the increase in cerebral blood flow during seizure activity. However, the production site of NO has not been clearly defined. Recent studies showed that constitutive nitric oxide synthase may be induced under certain conditions. Therefore, this study was aimed to investigate the change in endothelial nitric oxide synthase (eNOS), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) since these are involved in cerebral blood flow. Rats were treated with KA and killed at 6 hours, 1, 3, 6 and 12 days after seizure. Expressional changes were assessed by immunohisto-chemistry and RT-PCR. eNOS was detected in the blood vessels of the cerebral cortex of the control group, but was not detected in neurons. eNOS-positive neurons were induced in the cerebral cortex at 1 and 3 days after seizure and found in specific cortical areas, such as primary motor cortex, secondary motor cortex, primary somatosensory cortex, secondary somatosensory cortex, insular cortex, ectorhinal cortex, parietal association cortex, temporal association cortex, auditory cortex and visual cortex. The levels of eNOS mRNA increased at 1 and 3 days after seizure compared to controls. The staining intensity of eNOS-positive microvessels was elevated in samples obtained 1, 3, and 6 days after seizure compared to the control group. However, NPY- and VIP-positive neurons, and glial fibrillary acidic protein-positive astrocytes were not induced in the cerebral cortex after seizure. Therefore, specific neuroactive substances may be induced in the cerebral cortex after seizure. Nitric oxide, a free radical synthesized in the brain by NOS, is a messenger molecule that mediates vascular dilatation and neural transmission. Therefore, neurons showing induced eNOS-positivity and upregulated eNOS-positive microvessels may affect the cerebral blood flow and neuronal activity in the cerebral cortex after seizure.
Animals ; Astrocytes ; Auditory Cortex ; Blood Vessels ; Brain ; Cerebral Cortex* ; Dilatation ; Kainic Acid ; Microvessels ; Motor Cortex ; Neurons ; Neuropeptide Y ; Nitric Oxide ; Nitric Oxide Synthase ; Nitric Oxide Synthase Type III* ; Rabeprazole ; Rats* ; RNA, Messenger ; Seizures* ; Somatosensory Cortex ; Synaptic Transmission ; Vasoactive Intestinal Peptide ; Visual Cortex

BACKGROUNDPrevious studies have demonstrated interhemispheric functional connectivity alterations in schizophrenia. However, the relationship between these alterations and the disease state of schizophrenia is largely unknown. Therefore, we aimed to investigate this relationship using voxel-mirrored homotopic connectivity (VMHC) method.

METHODSThis study enrolled 36 schizophrenia patients with complete remission, 58 schizophrenia patients with incomplete remission and 55 healthy controls. The VMHC was calculated based on resting-state functional magnetic resonance imaging data. Differences in VMHC among three groups were compared using one-way analysis of variance. A brain region with a significant difference in VMHC was defined as a region of interest (ROI), and the mean VMHC value in the ROI was extracted for the post hoc analysis, i.e., pair-wise comparisons across the three groups.

RESULTSVMHC in the visual region (inferior occipital and fusiform gyri) and the sensorimotor region (paracentral lobule) showed significant differences among the three groups (P < 0.05, a false discovery rate method corrected). Pair-wise comparisons in the post hoc analysis showed that VMHC of the visual and sensorimotor regions in schizophrenia patients with complete remission and incomplete remission was lower than that in healthy controls (P < 0.05, Bonferroni corrected); however, there was no significant difference between the two patient subgroups.

CONCLUSIONSInterhemispheric functional connectivity in the sensorimotor and visual processing pathways was reduced in patients with schizophrenia, but this reduction was unrelated to the disease state; thus, this reduction may serve as a trait marker of schizophrenia.

Adult ; Brain ; physiology ; Brain Mapping ; Female ; Humans ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging ; Male ; Schizophrenia ; physiopathology ; Sensorimotor Cortex ; physiology ; Visual Pathways ; physiology

Kainic acid (KA) is a frequently used excitotoxin in experimental epilepsy research. The excitatory effect of KA leads to generalized convulsions when KA is administered systematically at convulsant doses. Nitric oxide (NO) is a gaseous messenger that plays a role in neurotransmission. NO is formed by NO synthase (NOS) from arginine. Purification and molecular cloning led to identification of at least three NOS isoforms designated as neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). In the central nervous system, NO seems to be involved in plasticity and cytotoxicity. Therefore, the present study has investigated the congruence of mRNA induction and protein expression of nNOS, eNOS, iNOS and neuropeptide Y (NPY) following KA-induced seizure activity. The patterns of NOS and NPY were studied by NADPH-diaphorase histochemistry, immunohistochemistry and RT-PCR in the rat brain. NADPH-d displayed a region-specific induction pattern. Regions of NADPH-d induction were the motor cortex and perirhinal cortex of KA treated group. Whereas NADPH-d neurons were not induced in auditory cortex, visual cortex, cingulate cortex, insular cortex, retrosplenial cortex and ectorhinal cortex of KA treated group. NPY neurons were not induced in all cortical areas of KA treated group. Subsequent to cortical neuronal induction, NADPH-d activity was increased in constitutive NADPH-d neurons of 1 and 3 days group of KA treatment. 1 and 3 days following KA administration, increased levels of nNOS, eNOS and iNOS mRNA were seen in the cerebral cortex. However, the level of NPY mRNA was decreased in 6 and 12 days after seizure. These findings demonstrate that mRNAs encoding for NOS isoforms are translated into the respective proteins following excitotoxic seizure.
Animals ; Arginine ; Auditory Cortex ; Brain ; Central Nervous System ; Cerebral Cortex* ; Cloning, Molecular ; Epilepsy* ; Gyrus Cinguli ; Immunohistochemistry ; Kainic Acid ; Motor Cortex ; Neurons* ; Neuropeptide Y* ; Neuropeptides* ; Neurotoxins ; Nitric Oxide Synthase* ; Nitric Oxide* ; Plastics ; Protein Isoforms ; Rats* ; RNA, Messenger ; Seizures ; Synaptic Transmission ; Visual Cortex

PURPOSE: Prenatal environmental conditions affect the development of the fetus. In the present study, we investigated the effects of exposure to music and noise during pregnancy on neurogenesis and thickness in the motor and somatosensory cortex of rat pups. METHODS: The pregnant rats in the music-applied group were exposed to 65 dB of comfortable music for 1 hour, once per day, from the 15th day of pregnancy until delivery. The pregnant rats in the noise-applied group were exposed to 95 dB of sound from a supersonic sound machine for 1 hour, once per day, from the 15th day of pregnancy until delivery. After birth, the offspring were left undisturbed together with their mother. The rat pups were sacrificed at 21 days after birth. RESULTS: Exposure to music during pregnancy increased neurogenesis in the motor and somatosensory cortex of rat pups. In contrast, rat pups exposed to noise during pregnancy showed decreased neurogenesis and thickness in the motor and somatosensory cortex. CONCLUSIONS: Our study suggests that music and noise during the developmental period are important factors influencing brain development and urogenital disorders.
Animals ; Brain ; Fetus ; Humans ; Mothers ; Motor Cortex ; Music ; Neurogenesis ; Noise ; Parturition ; Pregnancy ; Rats ; Somatosensory Cortex

Crossmodal information processing in sensory cortices has been reported in sparsely distributed neurons under normal conditions and can undergo experience- or activity-induced plasticity. Given the potential role in brain function as indicated by previous reports, crossmodal connectivity in the sensory cortex needs to be further explored. Using perforated whole-cell recording in anesthetized adult rats, we found that almost all neurons recorded in the primary somatosensory, auditory, and visual cortices exhibited significant membrane-potential responses to crossmodal stimulation, as recorded when brain activity states were pharmacologically down-regulated in light anesthesia. These crossmodal cortical responses were excitatory and subthreshold, and further seemed to be relayed primarily by the sensory thalamus, but not the sensory cortex, of the stimulated modality. Our experiments indicate a sensory cortical presence of widespread excitatory crossmodal inputs, which might play roles in brain functions involving crossmodal information processing or plasticity.
Animals ; Auditory Cortex/physiology* ; Neuronal Plasticity/physiology* ; Neurons ; Rats ; Thalamus ; Visual Cortex/physiology*

PURPOSE: The ascending reticular activating system (ARAS) is responsible for regulation of consciousness. In this study, using diffusion tensor imaging (DTI), we attempted to reconstruct the thalamocortical projections between the intralaminar thalamic nuclei and the frontoparietal cortex in normal subjects. METHODS: DTI data were acquired in 24 healthy subjects and eight kinds of thalamocortical projections were reconstructed: the seed region of interest (ROI) - the intralaminar thalamic nuclei and the eight target ROIs - the medial prefrontal cortex, dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, orbitofrontal cortex, premotor cortex, primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. RESULTS: The eight thalamocortical projections were reconstructed in each hemisphere and the pathways were visualized: projections to the prefrontal cortex ascended through the anterior limb and genu of the internal capsule and anterior corona radiata. Projections to the premotor cortex passed through the genu and posterior limb of the internal capsule and middle corona radiata; in contrast, projections to the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex ascended through the posterior limb of the internal capsule. No significant difference in fractional anisotropy, mean diffusivity, and fiber volume of all reconstructed thalamocortical projections was observed between the right and left hemispheres (p>0.05). CONCLUSION: We reconstructed the thalamocortical projections between the intralaminar thalamic nuclei and the frontoparietal cortex in normal subjects. We believe that our findings would be useful to clinicians involved in the care of patients with impaired consciousness and for researchers in studies of the ARAS.
Anisotropy ; Brain* ; Cerebral Cortex* ; Consciousness ; Diffusion Tensor Imaging ; Extremities ; Healthy Volunteers ; Humans* ; Internal Capsule ; Intralaminar Thalamic Nuclei* ; Motor Cortex ; Parietal Lobe ; Prefrontal Cortex ; Somatosensory Cortex ; Thalamus

BACKGROUND AND PURPOSE: To explore anatomic substrate of specific wandering patterns in patients with Alzheimer's disease (AD) by performing positron emission tomography with 18F fluorodeoxyglucose positron emission tomography (FDG PET). METHODS: Drug-naïve AD patients with wandering (n=80) and without wandering (n=262) were recruited. First, the specific pattern of wandering type was operationally classified according to specific wandering score and clinical assessment. Second, brain FDG PET was performed and fluorodeoxyglucose (FDG) uptake differences of specific brain regions according to wandering patterns were compared to those of non-wanderers. RESULTS: In patients with pacing pattern, FDG PET showed significant lower FDG uptake in both middle cingulum and left putamen cluster compared to non-wanderers. The right precuneus and supplementary motor area in patients with random pattern and left calcarine sulcus, right calcarine sulcus, right middle cingulum, and right post central gyrus in patients with lapping pattern had significantly lower FDG uptake compared to non-wanderers. CONCLUSIONS: This study showed that wandering in patients with AD had three distinct patterns. These specific patterns showed significant lower FDG uptake in specific brain areas compared to non-wanderers.
Alzheimer Disease* ; Brain ; Fluorodeoxyglucose F18 ; Humans ; Motor Cortex ; Occipital Lobe ; Parietal Lobe ; Positron-Emission Tomography ; Putamen ; Somatosensory Cortex