[A cognitive function test utilizing eye tracking technology in virtual reality].

AIM: There is a need for a cognitive function test that is less burdensome to perform cognitive function tests used to date and can detect mild changes in the cognitive function and mild cognitive impairment (MCI). We developed a cognitive function examination using a virtual reality device (VR-E). The purpose of this study was to verify its usability. METHODS: Seventy-seven participants (29 males and 48 females, average age 75.1 years old) were classified according to their Clinical Dementia Rating (CDR). To estimate the validity of VR-E in measuring cognitive function, we used the Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment-Japanese version (MoCA-J) scores as benchmarks. The MMSE was performed for all subjects, while the MoCA-J was performed for subjects with an MMSE score ≥20. RESULTS: VR-E scores were highest in the CDR 0 group (0.77±0.15, mean±SD), decreasing for subsequent groups (CDR 0.5: 0.65±0.19, CDR 1-3: 0.22±0.21). The receiver operating characteristic analysis showed that all three methods were able to distinguish CDR groups. For CDR 0 vs. 0.5, the areas under the curve for MMSE/MoCA-J/VR-E were 0.85/0.80/0.70, respectively, and those for CDR 0.5 vs. 1-3 were 0.89/0.92/0.90, respectively. The time required to complete VR-E was approximately 5 minutes. Of the 77 subjects, 12 were difficult to assess using the VR-E due to poor understanding or eye diseases or Meniere's syndrome. CONCLUSIONS: The present findings suggested that the VR-E can be used as a cognitive function test that correlates with existing standard assessments for dementia and MCI.

An immunohistochemical study of GABA A receptor gamma subunits in Alzheimer's disease hippocampus: relationship to neurofibrillary tangle progression.

Immunohistochemical characterization of the distribution of GABA(A) receptor subunits gamma1/3 and 2 in the hippocampus relative to neurofibrillary tangle (NFT) pathology staging was performed in cognitively normal subjects (Braak stage I/II, n = 4) and two groups of Alzheimer's disease (AD) patients (Braak stage III/IV, n = 4; Braak stage V/VI, n = 8). In both Braak groups of AD patients, neuronal gamma1/3 and gamma2 immunoreactivity was preserved in all hippocampal subfields. However, compared to normal controls neuronal gamma1/3 immunoreactivity was more intense in several end-stage AD subjects. Despite increased NFT pathology in the Braak V/VI AD group, GABA(A)gamma1/3 and gamma2 immunoreactivity did not co-localize with markers of NFT. These results suggest that upregulating or preserving GABA(A)gamma1/3 and gamma2 receptors may protect neurons against neurofibrillary pathology in AD.

A randomized cross-over study of a traditional Japanese medicine (kampo), yokukansan, in the treatment of the behavioural and psychological symptoms of dementia.

The effectiveness and safety of yokukansan (TJ-54), a traditional Japanese medicine (kampo) for the treatment of the behavioural and psychological symptoms of dementia (BPSD), were evaluated in 106 patients diagnosed as having Alzheimer's disease (AD) (including mixed-type dementia) or dementia with Lewy bodies. Patients were randomly assigned to group A (TJ-54 treatment in period I and no treatment in period II; each period lasting 4 wk) or group B (no treatment in period I and TJ-54 treatment in period II). BPSD and cognitive functions were evaluated using the Neuropsychiatric Inventory (NPI) and the Mini-Mental State Examination (MMSE), respectively. Activities of daily living (ADL) were evaluated using Instrumental Activities of Daily Living (IADL) in outpatients and the Barthel Index in in-patients. For the safety evaluation, adverse events were investigated. Significant improvements in mean total NPI score associated with TJ-54 treatment were observed in both periods (Wilcoxon test, p=0.040 in period I and p=0.048 in period II). The mean NPI scores significantly improved during TJ-54 treatment in groups A and B (p=0.002 and p=0.007, respectively) but not during periods of no treatment. Among the NPI subscales, significant improvements were observed in delusions, hallucinations, agitation/aggression, depression, anxiety, and irritability/lability. The effects of TJ-54 persisted for 1 month without any psychological withdrawal symptoms in group A. TJ-54 did not show any effect on either cognitive function or ADL. No serious adverse reactions were observed. The present study suggests that TJ-54 is an effective and well-tolerated treatment for patients with BPSD.

Immunohistochemical and immunoblot analysis of Dopamine and cyclic AMP-regulated phosphoprotein, relative molecular mass 32,000 (DARPP-32) in the prefrontal cortex of subjects with schizophrenia and bipolar disorder.

Dopamine and cyclic adenosine 3':5'-monophosphate (AMP)-regulated phosphoprotein, relative molecular mass 32,000 (DARPP-32), plays an important role in modulating the functions of various neurotransmitter systems. To explore the alterations in DARPP-32 in subjects with schizophrenia and bipolar disorder, we employed immunohistochemical and Western blotting techniques and examined the distribution and expression of DARPP-32 in the postmortem dorsolateral prefrontal cortex (DLPFC) from 12 subjects with schizophrenia, 10 subjects with bipolar disorder, and 11 control subjects. Immunohistochemical study demonstrated that DARPP-32 immunolabeling in the neuronal soma from subjects with schizophrenia and bipolar disorder was lower than in that from the controls. The results of the immunoblot analysis were consistent with those of the immunohistochemistry, and the amount of DARPP-32 in subjects with schizophrenia and bipolar disorder was found to be lower than that in the control subjects. The present study suggests that DARPP-32 decreases in the DLPFC of patients with schizophrenia and bipolar disorder, and further suggests that this decrease is associated with dysfunction of dopaminoceptive neurons in the DLPFC of patients affected by these two mental disorders.

GABA(A) receptor gamma subunits in the hippocampus of the rat after perforant pathway lesion.

Immunohistochemical and Western blotting techniques were employed to examine the alterations in immunostaining of the gamma-amino butyric acid (GABA) receptor subunits gamma 1/3 and 2 within the hippocampus of the rat brain at 1, 3, 7, 14, and 30 days after a unilateral perforant pathway lesion. At 1, 3, and 7 days post-lesion, we observed a remarkable decrease in gamma 1/3 neuropil staining in the deafferented zone (i.e., the outer molecular layer of the dentate gyrus ipsilateral to the lesion), although at 3 and 7 days post-lesion, staining intensity was considerably recovered. At 14 days post-lesion, the gamma 1/3 immunostaining was indistinguishable from that of controls and it appeared yet more robust at 30 days post-lesion. We also observed a slight decrease in gamma 2 neuropil staining until 7 days post-lesion, and an increase in gamma 2 staining at 30 days post-lesion. Western blot analysis demonstrated data that was relatively consistent with our immunohistochemical observations, although gamma 3 was hardly detectable. Our study suggests that gamma subunits of the GABA(A) receptor in the dentate gyrus display a plastic response to the deafferentation of the perforant pathway.

Immunohistochemical study of the hnRNP A2 and B1 in the hippocampal formations of brains with Alzheimer's disease.

To elucidate the post-transcriptional regulation in the subjects with Alzheimer's disease (AD), we employed immunohistochemical techniques and examined the expression of the heterogeneous nuclear ribonucleoprotein (hnRNP) A2 and B1 in the hippocampus with neurofibrillary tangle (NFT) neuropathology. In the mildly affected subjects (Braak stages I and II), the most intense A2 immunoreactivity was observed in the CA3 to CA1 neurons. In the moderately (Braak stages III and IV) and severely affected subjects (Braak stages V and VI), the CA1 region demonstrated a decrease in the number of A2 immunoreactive neurons and in immunoreactivity in the remaining neurons, while within the CA4 to CA2 in the severely affected subjects, the majority of neurons showed increased A2 immunoreactivity. An intense B1 immunoreactivity was observed throughout the CA subfields. In the CA1 subfield of the moderately affected subjects and in the extensive hippocampal regions of the severely affected subjects, a decrease in B1 immunoreactivity was observed. Double-immunolabeling studies demonstrated that tangle-bearing neurons reduced A2 and B1 immunoreactivity. Our study suggests that hnRNP A2 and B1 display different responses in the AD hippocampus, and further suggests that the post-transcriptional regulation is disturbed in neurons of the AD hippocampus.

Immunohistochemical and immunoblot analysis of gamma-aminobutyric acid B receptor in the prefrontal cortex of subjects with schizophrenia and bipolar disorder.

Immunohistochemical and immunoblot techniques were employed to examine the distribution and expression of GABA(B) receptors in the prefrontal cortex of postmortem subjects with schizophrenia and bipolar disorder. GABA(B)R1a/b immunoreactivity was observed in the neuronal soma and dendrites as well as in the neuropil in the control subjects. GABA(B)R1a/b immunolabeling in neurons from the subjects with schizophrenia and bipolar disorder was less intense than in those from the control subjects. In control subjects, the distribution of GABA(B)R2 immunoreactivity was found to be similar to that of GABA(B)R1a/b. GABA(B)R2 immunolabeling in neurons from the bipolar disorder group appeared less intense than that of the normal controls as well as that in schizophrenic groups. Immunoblot analysis demonstrated a significant decrease in GABA(B)R1a levels in schizophrenic subjects, while there was a significant decrease in GABA(B)R1a, GABA(B)R1b, and GABA(B)R2 levels in bipolar subjects compared with the controls. The present study suggests that the GABA(B) receptor is involved in the pathophysiology of schizophrenia and bipolar disorder, and further suggests that the patterns of changes in GABA(B) receptor subtypes are different between these two disorders.

Changes in hippocampal GABABR1 subunit expression in Alzheimer's patients: association with Braak staging.

Alterations in the gamma-aminobutyric acid (GABA) neurotransmitter and receptor systems may contribute to vulnerability of hippocampal pyramidal neurons in Alzheimer's disease (AD). The present study examined the immunohistochemical localization and distribution of GABA(B) receptor R1 protein (GBR1) in the hippocampus of 16 aged subjects with a range of neurofibrillary tangle (NFT) pathology as defined by Braak staging (I-VI). GBR1 immunoreactivity (IR) was localized to the soma and processes of hippocampal pyramidal cells and some non-pyramidal interneurons. In control subjects (Braak I/II), the intensity of neuronal GBR1 immunostaining differed among hippocampal fields, being most prominent in the CA4 and CA3/2 fields, moderate in the CA1 field, and very light in the dentate gyrus. AD cases with moderate NFT pathology (Braak III/IV) were characterized by increased GBR1-IR, particularly in the CA4 and CA3/2 fields. In the CA1 field of the majority of AD cases, the numbers of GBR1-IR neurons were significantly reduced, despite the presence of Nissl-labeled neurons in this region. These data indicate that GBR1 expression changes with the progression of NFT in AD hippocampus. At the onset of hippocampal pathology, increased or stable expression of GBR1 could contribute to neuronal resistance to the disease process. Advanced hippocampal pathology appears to be associated with decreased neuronal GBR1 staining in the CA1 region, which precedes neuronal cell death. Thus, changes in hippocampal GBR1 may reflect alterations in the balance between excitatory and inhibitory neurotransmitter systems, which likely contributes to dysfunction of hippocampal circuitry in AD.

Immunohistochemical study of hnRNP B1 in the postmortem temporal cortices of patients with Alzheimer's disease.

In order to examine the post-transcriptional regulations in Alzheimer's disease, we employed immunohistochemical techniques and examined the expression of heterogeneous nuclear ribonucleoprotein (hnRNP) B1 in the inferior temporal cortex of subjects with Alzheimer's disease. In the mild cases, intense B1 immunoreactivity was observed in neurons of layer V, and less intense immunoreactivity was observed in layers II and III. The overall distributions and intensities of B1 immunoreactivity were undistinguishable among mild, moderate, and severe cases. Double-immunolabeling with MC1 and B1 demonstrated that B1 immunoreactivity was preserved in the majority of neurofibrillary tangle (NFT)-bearing neurons. Our study suggests that hnRNP B1-associated post-transcriptional regulations are preserved in the inferior temporal cortex of Alzheimer's disease.

Immunohistochemical and immunoblot study of GABA(A) alpha1 and beta2/3 subunits in the prefrontal cortex of subjects with schizophrenia and bipolar disorder.

A number of investigations have provided a growing body of evidence of the involvement of the gamma-aminobutyric acid (GABA) transmitter system in the pathophysiology of schizophrenia and bipolar disorder. In this study, immunohistochemical and immunoblot techniques were employed in order to examine alterations of the GABA(A) receptor alpha1 and beta2/3 subunits in the prefrontal cortex from postmortem subjects with schizophrenia and bipolar disorder. alpha1 immunoreactivity was observed in the neuropil of the prefrontal cortex and in the neuronal soma in specimens from both groups, as well as from normal controls. alpha1 immunolabeling in the neuronal soma from the schizophrenic group was more intense than that of the other two groups. The distribution of beta2/3 immunoreactivity was similar to that of alpha1. beta2/3 immunolabeling in the neuronal soma from the schizophrenia and bipolar disorder groups was more intense than that of the normal controls. The densitometry measurements, as well as the immunoblot analysis for alpha1 and beta2/3 were highly consistent with the alpha1 and beta2/3 immunohistochemistry results. The present study suggests that the expression of these two GABA(A) receptor subunits was altered in subjects with schizophrenia and bipolar disorder, but that the patterns of change differed between those with these two disorders.

GABAA receptor gamma subunits in the prefrontal cortex of patients with schizophrenia and bipolar disorder.

Immunohistochemical and immunoblot techniques were employed in order to examine alterations of the GABAA receptor gamma subunits in the prefrontal cortex from postmortem subjects with schizophrenia and bipolar disorder. Immunohistochemically, gamma 1/3 immunolabeling in the neuronal soma in the prefrontal cortex from subjects with bipolar disorder was more intense than that of the controls and the subjects with schizophrenia. The intensity of gamma 1/3 immunolabeling of the schizophrenic subjects was comparable with that of the controls. Immunoblot analysis demonstrated a significant increase in the gamma 1 subunit in the bipolar subjects, whereas no remarkable difference was detected in the schizophrenic subjects. The present study suggests that the GABAA receptor gamma subunit is differentially involved in schizophrenia and bipolar disorder, and that the gamma subunit is up-regulated in the prefrontal cortex of subjects with bipolar disorder.

Alterations of heterogeneous nuclear RNP A2 and B1 in the hippocampus of the rat after perforant pathway lesion.

We examined alterations in post-transcriptional regulation following deafferentation of the perforant pathway by focusing on heterogeneous nuclear ribonucleoprotein (hnRNP) A2 and B1 in rat hippocampi subjected to perforant pathway lesions. In control brains, immunoreactivity to both was observed in the nuclei of neurons throughout the hippocampus using immunohistochemical techniques. From 1 to 14 days post-lesion, a slight increase in A2 immunoreactivity was observed in neurons within the dentate granular layer as well in the pyramidal cells of the cornus Ammon fields ipsilateral to the lesion. In contrast, we observed a marked decrease in B1 immunoreactivity in the same regions at 1, 3 and 7 days post-lesion. All these alterations, however, were transient. A2 immunoreactivity returned to normal levels by 30 days post-lesion, and B1 immunoreactivity had completely recovered by 14 days post-lesion. The results of immunoblot analysis for A2 and B1 were wholly consistent with immunohistochemical observations. Our study suggests that post-transcriptional regulation in the hippocampal neurons changes after a perforant pathway lesion. Our study further suggests that the functions of hnRNPA2 and B1 are different, as each was differentially involved in the plastic response to deafferentation of the perforant pathway.

Alterations of NMDAR1 and NMDAR2a/B immunoreactivity in the hippocampus after perforant pathway lesion.

Immunohistochemical techniques were employed to examine the changes in immunolabeling of the N-methyl-D-aspartate (NMDA) receptor subunits NMDAR1 and NMDAR2A/B within the hippocampus 1, 3, 7, 14 and 30 days after a unilateral perforant pathway lesion was made in a rat brain. At 1 day post-lesion, we observed a decrease in NMDAR1 immunolabeling in the granule cells in the dentate gyrus as well as in the mossy cells in the polymorphic region ipsilateral to the lesion, while an increase in diffuse neuropil labeling was observed. At 3 days post-lesion, we observed a marked increase in NMDAR1 immunolabeling in the outer molecular-layer of the dentate gyrus as well as in the stratum moleculare in the CA fields ipsilateral to the lesion. Although this increase was less marked at 7 and 14 days post-lesion, an increase in NMDAR1 immunolabeling was evident at 30 days post-lesion. In contrast, although a transient increase in NMDAR2A/B immunolabeling was observed in the outer molecular layer at 3 days post-lesion, no other changes were detectable at any of the time points examined. Our study suggests that each subunit of the NMDA receptor displays a different response to deafferentation of the perforant pathway. We have previously observed that changes in the immunoreactivity of the receptor subunits of another class of glutamate receptor, a-amino-3-hydroxy-5-methyl-4-isoaxolepropionate (AMPA), occur at 30 days post-lesion but not after a relatively short survival time. NMDA receptor subunits demonstrate an earlier response to the loss of the perforant pathway fibers than do the AMPA receptor subunits.

Immunohistochemical localization of GABAB receptor in the entorhinal cortex and inferior temporal cortex of schizophrenic brain.

Immunocytochemical techniques were employed to examine the changes in immunolabeling of the gamma-aminobutyric acid (GABA)B receptor within the entorhinal cortex and inferior temporal isocortex of the schizophrenic brain. In the entorhinal cortex of the control subjects, an intense immunoreactivity was observed in the soma and processes of stellate cells in Layer II, in pyramidal cells in Layers II, III, and V, and in nonpyramidal interneurons. In subjects with schizophrenia, GABA(B) immunoreactivity was markedly reduced in pyramidal cells throughout the layers. In the inferior temporal cortex of the controls, both pyramidal cells and nonpyramidal interneurons demonstrated an intense immunoreactivity, while in the same region of the schizophrenic brain a marked reduction of the GABA(B) immunolabeling was observed in pyramidal cells in Layer V. These findings suggest that in the entorhinal cortex and the inferior temporal cortex of the schizophrenic brain, the expression of the GABA(B) receptor is reduced, and raise the possibility that GABA(B) receptor dysfunction is involved in the pathophysiology of schizophrenia.