ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

DEFECTIVE herpes simplex virus (HSV-1) vector containing either the lac-z gene or the tyrosine-hydroxylase (TH) gene was added to primary rat neocortex cultures and gene transfer was assessed using immunohistochemical procedures. While we were able to confirm lac- and TH-expression in vitro, exposure to the vector was accompanied by marked neurotoxic reactions as indicated by severe cell loss in vitro. Furthermore, when genetically altered cells were implanted into the adult rat striatum, a few lac-z positive cells without neurites were present but not a single TH-expressing cell could be found. The value of the HSV-1 vector system to transfer genes in the adult rat brain should therefore be viewed with caution.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

THE effects of MSG treatment on NGF and NPY levels were analysed in the hypothalamus, pituitary, adrenal, thyroid and testis of adult rats. Daily i.v. injections of MSG (1 gkg-1for 1 week) induced an increase of NGF in the hypothalamus (control (C) = 378 ± 54; saline (S) = 369 ± 36; MSG = 479 ± 35pgg-1tissue; p < 0.001) and pituitary (C = 310 ± 34; S = 376 ± 114; MSG = 576 ± 98pgg-1tissue; p < 0.01). Hypothalamic and pituitary NPY concentrations were also altered in the MSG- treated rats. Compared with saline-treated rats, the NPY concentration increased by 43% in the hypothalamus and 37.5% in the pituitary of MSG-treated rats. No significant changes in NGF and NPY content were found in the adrenal or thyroid of treated animals. These results suggest that hypothalamic and pituitary NGF and NPY levels may be involved in the control of neuroendocrine functions that are affected by MSG treatment.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

THE aim of this investigation was to study whether melatonin affects the release of oxytocin and vasopressin by the pituitary neurointermediate lobe of the Syrian hamster in vitro. The effect of melatonin was studied on the unstimulated (pre- and post-K+-stimulated) release of oxytocin and vasopressin and on the response to K+stimulation. Melatonin significantly inhibited unstimulated release of these hormones in all concentrations (10-11M, 10-9M and 10-7M) studied. K+-stimulated release of oxytocin and vasopressin was significantly decreased by the 10-9M dose of melatonin. It is concluded that melatonin is active in modifying the release of these peptides in the Syrian hamster neurointermediate lobe, as it has been previously demonstrated in the rat hypothalamus.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

THERE is anatomical and experimental evidence suggesting that tachykinins have a role in the regulation of secretion of anterior pituitary hormones. In this investigation, the effects of neuropeptide K and neuropeptide gamma on the secretion of GH were studied in vivo and in vitro. Injections of neuropeptide K into the third ventricle of freely moving, ovariectomized rats resulted in a significant increase of plasma GH, but neuropeptide gamma induced no significant changes in these levels, although it did induce a significant increase in GH pulse height. In vitro, neither neuropeptide K nor neuropeptide gamma had any apparent effect on GH release from hemipituitaries incubated for 2 h. These results suggest that neuropeptide K may have a modulatory function in the regulation of GH secretion from the anterior pituitary, through an action exerted at the hypothalamic level, and the effects of neuropeptide gamma seem to be more marginal.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BRAIN corticosteroid receptors are regulated by neural control as well as by adrenal hormones. In this study we tested the effect of septo-hippocampal cholinergic lesions on the binding capacity of corticosteroid receptors. Rats were injected with ibotenic acid into the medial septum, and hippocampal type I and type II, and hypothalamic type II corticosteroid receptors were measured 15 days later. In lesioned animals the number of type I corticosteroid receptors in the hippocampus was increased and their affinity decreased. In the hypothalamus only an increase of type II corticosteroid receptors was observed. As expected, lesioned rats showed an increase in basal plasma corticosterone levels.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

THE effect of interleukin-lβ (IL-1β, 10 ng per 5μl i.c.v.) on noradrenaline release in the hypothalamus of freely moving rats and on plasma ACTH levels has been studied, respectively by intracerebral microdialysis and radioimmunoassay. IL-1β induced an early increase in noradrenaline (NA) release in the paraventricular nucleus (PVN) followed by a second long-lasting enhancement starting from 80 min, with a maximum at 140 min (187 ± 14%). Heat-denatured IL-1β induced only the early increase without any other change at later times. IL-1β did not significantly affect NA release in the area surrounding the PVN at any time. IL-1β increased ACTH levels at 2 and 3 h. Indomethacin (10 mg kg-1, i.p.) prevented the noradrenergic and ACTH responses. The NA system in the PVN plays a part in the mechanism controlling the ACTH response induced by IL-1.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

PARTIAL lesions were made with kainic acid in the interpeduncular nucleus of the ventral midbrain of the rat. Compared with sham-operated controls, lesions significantly (p < 0.25) blunted the early (< 60min) free- field locomotor hypoactivity caused by nicotine (0.5 mgkg-1, i.m.), enhanced the later (60–120 min) nicotine-induced hyperactivity, and raised spontaneous nocturnal activity. Lesions reduced the extent of immunohistological staining for choline acetyltransferase in the interpeduncular nucleus (p < 0.025), but not for tyrosine hydroxylase in the surrounding catecholaminergic A10 region. We conclude that the interpeduncular nucleus mediates nicotinic depression of locomotor activity and dampens nicotinic arousal mechanisms located elsewhere in the brain.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

SEVERAL growth factors are candidates for the therapy of motor neurone diseases. However, there is no efficient, safe, and practicable administration route which hampers the clinical use of these potentially therapeutic agents. We show that specific and high yield gene transfer into motor neurones can be obtained by peripheral intramuscular injections of recombinant adenoviruses. These vectors are retrogradely transported from muscular motor units to motor neurone cell bodies. Gene transfer can thus be specifically targeted to particular regions of the spinal cord by appropriate choice of the injected muscle. The efficiency of gene transfer is high, with 58– 100% of the motor neurones afferent to the injected muscle expressing the transgene. This new therapeutic protocol allows specific targeting of motor neurones without lesioning the spinal cord, and should avoid undesirable side effects associated with systemic administration of therapeutic factors.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

UNLIKE most neurones, the dentate granule cells continue to be produced in adults. Recently our study has demonstrated that a highly polysialylated neural cell adhesion molecule (NCAM-H) is a reliable molecular marker for newly generated and developing dentate granule cells. Here we examined age-related changes in the number of newly generated and developing granule cells. In rats injected with 5-bromo-2'-deoxyuridine (BrdU), a thymidine analogue, at 35 days to 18 months of age, double immunohistochemistry for BrdU and NCAM-H showed that the numbers of NCAM-H-positive and BrdU-/NCAM-H-positive granule cells gradually decreased over more than one year, but they were still detected in 18-month-old rats. These findings indicate that newly formed and developing granule cells occur in the dentate gyrus of young and aged rats, but the number of these cells decreases with age.

ISSN:0959-4965    

出版商:OVID    

年代:1995

数据来源: OVID