摘要:

AbstractCalcium channel currents have been recorded from cultured rat sensory neurons at clamp potentials of between ‐30 and +120 mV. At large depolarizing potentials between +50 and +120 mV, the current was outward. This outward current was shown to be largely due to ions passing through calcium channels, because it was substantially although generally incompletely blocked by Cd2+(1 mM) and ω‐conotoxin (1 μM). Internal GTP‐γ‐S (100 μM) and to a lesser extent GTP (1 mM) reduced the amplitude and slowed the activation of the outward, as well as the inward calcium channel current. Baclofen (100 μM) reversibly inhibited both the inward and outward currents. These results suggest that the effect of baclofen and G protein activation on calcium channel currents is not due to a shift in the voltage‐dependence of channe

ISSN:0953-816X    

DOI:10.1111/j.1460-9568.1990.tb00386.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractWe have investigated the effects of glucocorticoid manipulation on corticotrophin‐releasing factor (CRF‐41) in the neurointermediate lobe (NIL) and median eminence (ME) of the rat using a radioimmunoassay specific for CRF‐41. CRF‐41 content in the NIL (88 ± 7 fmol, mean ± SEM) was not significantly altered by administration of dexamethasone in drinking water for 12 days (67 ± 9 fmol) or adrenalectomy for 12 days (96 ± 17 fmol). The saline‐stimulated increase in NIL CRF‐41 content (154 ± 24 fmol) was not affected by dexamethasone (152 ± 24 fmol) or adrenalectomy (179 ± 21 fmol). In contrast, the content of CRF‐41 in the ME declined following dexamethasone treatment (1247 ± 92 fmol to 864 ± 26 fmol), or adrenalectomy (854 ± 78 fmol). Our results provide further evidence that CRF‐41 in the NIL and ME can be

ISSN:0953-816X    

DOI:10.1111/j.1460-9568.1990.tb00387.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractAxon degeneration after disruption of fibre tracts in the mammalian nervous system is accompanied by myelin breakdown which leads to changes in its magnetic resonance properties. In two patients with pure motor strokes due to small ischaemic lesions restricted to the internal capsule, magnetic resonance imaging disclosed a narrow band of pathological signal increase descending band‐like into the brain stem and ascending to the precentral gyrus, which corresponded to the well‐known path of the pyramidal tract. The findings suggest that in man anterograde and possibly retrograde fibre degeneration can be tracedin vivoby conventional magnetic resonance imaging techniques. Critical conditions are the presence of small, strategically located lesions, appropriate choice of imaging plane, and the interval between time of lesion and of imaging. This demonstration may open a new era for functional neuroanatomy of

ISSN:0953-816X    

DOI:10.1111/j.1460-9568.1990.tb00388.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractCell lines in which tyrosine hydroxylase was introduced either by infection or transfection were used in grafting experiments in a rat model of Parkinson's disease obtained by unilateral lesion of the substantia nigra. A neuroblastoma NS20 Y cell line which synthesizes only L‐DOPA and a neuroendocrine AtT‐20 cell line which produces dopamine were obtained. They were grafted into denervated striata and their ability to compensate for the dopaminergic deficit was studied. Both modified cell types displayed a rapid partial reversal of apomorphine‐induced turning behaviour. No effect was observed with the control unmodified cell lines. We discuss the usefulness of engineered cell lines to address the fundamental issues in grafting experiments and more particularly in the therapy of Parkinson's di

ISSN:0953-816X    

DOI:10.1111/j.1460-9568.1990.tb00389.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0953-816X    

DOI:10.1111/j.1460-9568.1990.tb00390.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY