摘要:

The initial cortical response of the trigeminal somatosensory evoked magnetic fields was measured for electrical stimulation of the lower lip in eleven subjects. The stimulus frequency was 0.7 Hz and stimulus intensity was nine times sensory threshold. The initial contralateral response was detected in 20 hemispheres at a latency of 14.6 ± 1.3 ms and was named N15m. The equivalent current dipole of N15m was localized at the posterior bank of the central sulcus with anterior–superior orientation, and inferior to the dipole of N20m for median nerve stimulation.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

The perception of the spatial location of an auditory stimulus can be captured by a spatially disparate visual stimulus, a phenomenon known as the ventriloquism effect. This study investigated the temporal and spatial dependency of this illusion. In the temporal domain, only disparities of 50–100 ms were perceived as simultaneous, and disparities where the visual stimulus occurred before the auditory stimulus were more effective in creating the illusion. In the spatial domain, the illusion was elicited most strongly at spatial disparities below spatial discrimination thresholds. There was also a significant interaction between temporal and spatial disparities. These results indicate that both temporal and spatial parameters are critical in the perception of real world objects in extrapersonal space.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Phencyclidine (PCP) reduced social behavior (SB) in a dose- and time-dependent fashion. However, no such SB deficit was observed on repeated treatment with methamphetamine for 14 days. The SB deficit produced by treatment with PCP (10 mg/kg/day) for 14 days, which persisted for 28 days after withdrawal, was attenuated by clozapine (10 mg/kg/day) given for 7 days, whereas haloperidol for 7 days had no effect. Clozapine, but not haloperidol, alone at the same treatment dose increased SB in saline-treated mice. These results suggest that the proposed PCP model in mice will provide a tool to test beneficial effects of atypical antipsychotics on social dysfunction in schizophrenia, and contribute to our understanding of the mechanisms by which clozapine improves SB deficit.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Rat septohippocampal fibres are known to originate from GABAergic parvalbumin-containing, fast-firing, fast-conducting neurons and from cholinergic slow-firing, slow-conducting neurons. In the present electron microscopic study, based on immunocytochemical demonstration of parvalbumin and choline acetyltransferase in transverse and horizontal septal sections, it was shown that parvalbumin-immunoreactive fibres are myelinated, but the vast majority of cholinergic fibres are not. As revealed, especially in horizontal sections, the cholinergic axons show considerably finer calibres than parvalbumin-containing ones. These results confirm and extend our previous light microscopic findings. It can be concluded that differences in conduction velocities, presence or absence of myelin sheaths and differences in axonal diameters are correlated in the septohippocampal pathway.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Brain-derived neurotrophic factor (BDNF) can produce hyperalgesia in the adult rat. Here we assessed whether changes in the spinal release of the nociceptive peptide substance P (SP) contributes to this effect. Antibody-coated microprobes revealed a significant basal release of SP in the dorsal hornin vivothat was increased following acute knee inflammation. Microinjection of BDNF into the grey matter (0.5 μl, 10−5M) altered SP release neither in rats with normal knees nor in rats with inflamed knee joints. In the lumbar dorsal horn slice preparation in vitro, superfusion with BDNF (100 ng/ml) could reduce SP release evoked by electrical dorsal root stimulation without modyfing SP basal outflow. It is unlikely, therefore, that enhanced spinal SP release mediates the hyperalgesic effect of BDNF.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

cGMP is thought to play a role in cerebellar signalling yet its production within Purkinje cells has never been detected. In the present study, the hydrolysis of a fluorescent substrate analogue, 2′-O-anthranyloyl cyclic GMP, by type 5 phosphodiesterase was monitored within Purkinje cells in slices and in culture. Nitric oxide, either endogenously released from adjacent neurons or pharmacologically applied, accelerated the rate of hydrolysis in a manner that was dependent on soluble guanylyl cyclase, demonstrating that nitric oxide triggers cyclic GMP production in Purkinje cells, which in turn activates type 5 phosphodiesterase. We conclude that NO acts as an intercellular messenger in the cerebellar cortex and that parallel fibre terminals are a probable source of nitric oxide.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Here we describe the expression of a third member of the VPS10 domain containing receptor family, SorCS, during mouse embryonal and early postnatal nervous system development. SorCS is expressed in a unique transient and dynamic pattern in regions where cells proliferate, as well as in areas where already differentiated cells reside, including the cerebral cortex, the ventral tegmental area, and the globus pallidus. Transcripts were absent from fiber tracts hinting at a neuronal expression. The only exception was hybridization signals on the developing optic nerve correlating with the appearance of astrocytes migrating into the retina.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID