ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

TWENTY Alzheimer's disease (AD) patients with defined apolipoprotein E (APOE), α1-antichymotrypsin (ACT) and presenilin-1 (PS-1) intronic genotypes were examined to quantify the regional cerebral metabolic rate of glucose (rCMRglc) using positron emission tomography (PET) and1F-2-fluoro-2-deoxy-D-glucose (FDG). The frontal rCMRglc was significantly increased in patients with the APOE ε4 allele in a dose-dependent fashion. In contrast, the temporo-parietal rCMRglc was significantly reduced in ACT type A allele (ACT*A) carriers compared with those in non-ACT*A carriers. The PS-1 type 1 intronic allele had no significant effects on rCMRglc in any cerebral region. These results suggest that both the APOE and ACT genes may play a distinct role in the progression of AD as monitored by imaging studies of cerebral glucose utilization.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

MALE zebra finches learn to imitate a tutor's song through auditory and motor learning during a sensitive period. The molecular aspects of auditory-dependent learning was investigated using protein kinase C (PKC) as a molecular marker for synaptic plasticity. We found a transient increase in the expression of PKC in the robust nucleus of the archistriatum (RA) during a sensitive period. Furthermore, both early deafening by cochlea removal and song deprivation inhibited the increase of PKC enzyme activity. The results strongly suggest that PKC is an important enzyme related to the synaptic plasticity of RA neurons during a sensitive period of song learning in the zebra finch.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

THE 5-HT2C(serotonin-2C) receptor has been implicated along with other components of the 5-HT system in the pathophysiology and pharmacotherapy of migraine. To investigate whether the 5-HT2Creceptor gene contributes to the risk of migraine we performed an association study of allelic variation at codon 23 (Cys or Ser) of the gene in 242 migraineurs, including 73 with aura, and 129 controls. No differences nor trends in allele or genotype frequencies were seen in the migraineurs compared to the controls. Neither did the frequencies vary significantly in migraineurs with and without aura, or if men and women were analysed separately. In conjunction with an earlier negative linkage study, these data indicate that the 5-HT2Creceptor gene does not contribute to the genetic predisposition to migraine.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

DORSAL column axons can regenerate into peripheral nerve grafts. The neurotrophin BDNF and its receptor TrkB are synthesized in dorsal root ganglion neurons, and have been implicated in regeneration. The aim of this study was to examine the distribution of BDNF and TrkB in dorsal column axons which regenerated into a peripheral nerve graft. BDNF-stained axons were found in all regions of the graft. BDNF was also expressed in small neurons in the superficial dorsal horn adjacent to the graft. TrkB was not found in any regenerating axons. Thus BDNF and TrkB are differentially expressed in regenerating dorsal column axons. In these axons BDNF may play a role that is independent of TrkB.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

THE immunocytochemical localization of tachykinin NK-3 receptor (NK-3R) was studied in rat spinal cord using a mouse monoclonal antibody directed against the C-terminus peptide (434-465) of the human NK-3R. Light microscopic labeling prevailed in lamina II and lamina X. Under the electron microscope, the immuno-labeling in lamina II involved mainly dendritic spines inside glomeruli, preterminal axons and axon terminals. This suggests that neurokinin B can modulate primary afferent, sensory information, both post-and pre-synaptically. These actions are likely to involve extrasynaptic diffusion of the peptide, since NK-3R immunoreactivity was not found in association with postjunctional differentiations.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

LATE component event related potentials (ERP) and concomitant electrodermal activity (EDA) measures of the orienting reflex (OR) were undertaken in 50 normal subjects. Our group recently developed a model to quantify electrodermal activity in conventional ERP paradigms (auditory oddball) with short interstimulus intervals (ISI). The method was used to classify the presence or absence of skin conductance response following each auditory target stimulus. Using a conventional paradigm in which data is traditionally averaged, single-trial target ERPs were sorted into those with a skin conductance response OR (ERP+OR) and those without (ERP−OR) an OR, and ERP sub-averages of the two groups were derived. The ERP+ORshowed significantly larger P300 amplitudes and relatively earlier N200 and P300 latency than those of the ERP−OR. These findings suggest that using concomitant SCR-ERP measures, separate ERP related processes can be determined, that are complementary to the traditional average measure.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

WE have used whole brain fMRI and canonical variate analysis to investigate the anatomical location of brain activity subserving episodic memory encoding and recognition. Recognition of previously presented words did not specifically activate right prefrontal areas although right-sided activations were seen during transitions between the target and reference phases of the paradigm. Encoding was associated with left sided prefrontal activation, but this was within Broca's area rather than dorsolateral prefrontal cortex. The temporal resolution of fMRI, combined with analysis of the apparent functional connectivity of activations observed, revealed activity within complex networks each functionally specialized for the demands of particular aspects of a cognitive task.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

THE suprachiasmatic nuclei (SCN) of the hamster can be maintained for several daysin vitro, allowing electrophysiological investigation of the mammalian circadian clock. Application of pituitary adenylate cyclase activating peptide (PACAP) at Zeitgeber time (ZT) 6 on the first dayin vitrocan phase shift the rhythm of firing rate expressed by SCN neurons on a subsequent dayin vitro. Here we report that co-application of neuropeptide Y (NPY) will block the phase-shifting action of PACAP. This blocking action is mimicked by [Leu31,Pro34]NPY and [D-Trp32]NPY but not by NPY22–36or avian pancreatic polypeptide. The results indicate that NPY has actions in the SCN via receptors distinct from the Y2 receptor, which mediates the phase-shifting action of NPY.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

FIVE patients with left visual neglect after right hemisphere lesions were examined with a line bisection and a reading task under five different conditions: head and trunk straight ahead, head or trunk oriented 20° to the left and head or trunk oriented 20° to the right. Fixation was always straight ahead. Five patients with right hemisphere lesions but without neglect and five normal subjects served as controls. In all neglect patients, turning the head or trunk to the left reduced line bisection and reading errors significantly as compared with the other three conditions and with the control groups. The modulation of neglect behaviour by trunk as well as head position supports the hypothesis of a disturbed egocentric coordinate system leading to neglect.

ISSN:0959-4965    

出版商:OVID    

年代:1997

数据来源: OVID