Masahiko Iwakiri

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 Alzheimers 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 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.

Immunohistochemical and immunoblot study of GABAA α1 and β2/3 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 γ-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 GABAA receptor α1 and β2/3 subunits in the prefrontal cortex from postmortem subjects with schizophrenia and bipolar disorder. α1 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. α1 immunolabeling in the neuronal soma from the schizophrenic group was more intense than that of the other two groups. The distribution of β2/3 immunoreactivity was similar to that of α1. β2/3 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 α1 and β2/3 were highly consistent with the α1 and β2/3 immunohistochemistry results. The present study suggests that the expression of these two GABAA receptor subunits was altered in subjects with schizophrenia and bipolar disorder, but that the patterns of change differed between those with these two disorders.

Immunohistochemical localization of γ-aminobutyric acidB receptor in the hippocampus of subjects with schizophrenia

Recent studies have demonstrated the involvements of gamma-aminobutyric acid (GABA) neurotransmitter systems in the schizophrenic brain. In order to further elucidate the alterations of this system in schizophrenia, we employed immunohistochemical techniques and examined the expression and anatomical distribution of the GABA(B) receptor in the hippocampus of five subjects with schizophrenia and three age-matched controls. In the control hippocampus, the most intense immunoreactivity was observed in the soma and processes of multipolar interneurons throughout the hippocampus. Pyramidal cells too were intensely labeled in their soma and proximal portion of dendrites, although the labeling intensity was varied in each subregion. For example, in the CA1 subfield, the labeling intensity of pyramidal cells was much less intense than that in the CA3 and CA2 subfields. In the subjects with schizophrenia, GABA(B) immunoreactivity was markedly reduced in granule cells as well as in pyramidal cells throughout the CA fields. In interneurons, GABA(B) labeling was relatively preserved compared to that in pyramidal cells. Our findings suggest that in the hippocampus of schizophrenic patients the expression of the GABA(B) receptor is reduced, and raise the possibility that this reduction contributes to the pathophysiological process in the schizophrenic brain.

Immunohistochemical and immunoblot analysis of γ-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 γ-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 GABAB 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.

An immunohistochemical study of GABAA receptor gamma subunits in Alzheimer’s disease hippocampus: relationship to neurofibrillary tangle progression

Immunohistochemical characterization of the distribution of GABAA receptor subunits γ1/3 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 Alzheimers disease (AD) patients (Braak stage III/IV, n = 4; Braak stage V/VI, n = 8). In both Braak groups of AD patients, neuronal γ1/3 and γ2 immunoreactivity was preserved in all hippocampal subfields. However, compared to normal controls neuronal γ1/3 immunoreactivity was more intense in several end‐stage AD subjects. Despite increased NFT pathology in the Braak V/VI AD group, GABAAγ1/3 and γ2 immunoreactivity did not co‐localize with markers of NFT. These results suggest that upregulating or preserving GABAAγ1/3 and γ2 receptors may protect neurons against neurofibrillary pathology in AD.

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 Alzheimers 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.

Effects of sodium valproate on behavioral disturbances in elderly outpatients with dementia.

The behavioral and psychological symptoms of dementia (BPSD) have a negative impact on the quality of life of patients as well as on that of caregivers. Although BPSD often need to be managed using psychotropic agents, an increased mortality rate was reported in patients with dementia taking antipsychotic medications. Thus, there is urgent need to develop a safer treatment for BPSD in demented patients. Sodium valproate (VA) was originally developed for epilepsy, but is now also used as a mood stabilizer. In addition, a number of recent papers have reported that VA is effective for the management of BPSD, although the results are still controversial. The aim of the present study was to examine the efficacy and tolerability of VA in outpatients with BPSD. We retrospectively reviewed the charts of consecutive Japanese patients with dementia seen in the outpatient facility of Ishizaki Hospital. This study protocol was approved by the Internal Review Board of Ishizaki Hospital. The subjects were diagnosed according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders criteria and were treated using VA for BPSD between April 2002 and July 2005. All of the patients underwent physical, neurological and laboratory examinations as well as brain magnetic resonance imaging (MRI) or brain computed tomography (CT) scans. Patients with a reversible cause of dementia or with a diagnosis other than dementia (e.g. delusional disorder) were excluded. Patients with delirium were enrolled if they had dementia prior to the manifestation of delirium. The severity of dementia was determined using the Clinical Dementia Rating scale (CDR) at baseline. Some of the patients were simultaneously taking other medicines for physical conditions. These treatment regimens remained largely unchanged during the VA evaluation period. Charts of all the subjects were reviewed to determine the effects of VA on BPSD, the dose of VA and the side-effects of VA. The efficacy of VA for each BPSD in each patient was evaluated as follows, according to the clinical assessment of two independent doctors, and according to the clinical global impression (CGI): “very much improved” and “much improved” were considered to be clinically meaningful responses. In addition, we calculated the efficacy rate for each symptom. The number of patients with improvement of a target symptom was divided by the total number of patients having that target symptom, such as hallucination/ delusion, irritability/excitement, aggression/agitation, insomnia/delirium, inappropriate/purposeless behaviors, and other symptoms. The final rating at the end of 8 weeks was used to assess the effects of VA. The influence of the possible prognostic factors (i.e. age, sex, severity of dementia, diagnosis of dementia) or the effect of treatment with tiapride on prognosis was analyzed by univariate logistic regression analysis (SPSS ver. 11.0.1J). Statistical significance was accepted when the P-value was less than 0.05. We enrolled 110 patients who had been treated with VA (age, mean 1 standard deviation 80.4 1 7.2 years, 26 patients taking only VA and 84 patients taking VA plus tiapride) (Table 1). At 8 weeks after the start of VA treatment, the average daily dose was 134.6 mg (range 40–300 mg), and daily dose of tiapride was 34.1 mg (range 10–75 mg). In 13 of the 110 (11.8%) patients, the following adverse effects were observed: unsteady gait (n = 8), sleepiness (n = 2), nausea (n = 1), dizziness (n = 1) and headache (n = 1). Blood examination including blood counts, liver dysfunction and blood ammonia revealed no abnormal findings. Among the 110 patients, 10, 42, 34, 21 and three were very much improved, much improved, minimally improved, no change, or worsened, respectively. Thus, either very much or much Geriatr Gerontol Int 2010; 10: 324–326

GABAA receptor γ subunits in the hippocampus of the rat after perforant pathway lesion

Abstract Immunohistochemical and Western blotting techniques were employed to examine the alterations in immunostaining of the γ-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.