A long-term effect of an early stimulation of the lateral hypothalamus on the acquisition and extinction of a food reinforced operant conditioning in the rat

ABSTRACT The internal variations (i. e. in timing, duration and amplitude) of the LH surge mechanism within individual rats were examined by monitoring from 3 to 7 successive pro-oestrous LH surges in each of 5 regular 4-day cycling rats fitted with chronic intravenous cannulas. On each successive pro-oestrus blood was collected (0.5–0.6 ml hourly from 14.00–21.00) for radioimmunoassay of LH. The surgery of cannulation had no long-term effect on the regularity of the oestrous cycle. Two rats did, however, show briefly irregular cycles, including one with a 9-day period of anoestrus (pseudopregnancy). In three of the five rats successive pro-oestrous plasma LH curves (4 in one and 3 each in the other two) were internally very consistent in timing, shape and amplitude, However, between each 2 of these 3 animals there were distinct differences in the LH secretory patterns, by as much as 2 h in timing of the onset of the surge and its peak amplitude. The first two surges of the other two rats were atypical of their subsequent surges, which were mostly consistent in timing and amplitude. The pro-oestrous LH surge following the 9-day period of anoestrus was advanced by 2 h and elevated to twice the mean peak amplitude of the cyclic LH surges in that rat. Subsequently, post-PSP surges were studied in rats made pseudopregnant by mechanical stimulation of the cervix. In all cases the immediate post-PSP surge occurred earlier in the afternoon and with a greater peak amplitude than the subsequent cyclic LH surge in the same rat.

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Long-term effect of cyclic AMP on N-glycosylation is caused by an increase in the activity of the cis-prenyltransferase

Biochemical Journal ◽

10.1042/bj3160575 ◽

1996 ◽

Vol 316 (2) ◽

pp. 575-581 ◽

Cited By ~ 13

Author(s):

Matthias KONRAD ◽

Wolfgang E. MERZ

Keyword(s):

Cyclic Amp ◽

Kinase Activity ◽

Fold Increase ◽

Term Effect ◽

Long Term Effect ◽

Choriocarcinoma Cells ◽

Specific Stimulation ◽

Stimulation Of ◽

In Cells

Previously we have shown that long-term pretreatment of JEG-3 choriocarcinoma cells with 8-bromo-cAMP increases the capacity for N-glycosylation that was caused by an 8–10-fold enlargement of the dolichol pyrophosphoryl oligosaccharide (Dol-PP-oligosaccharide) pool [Konrad and Merz (1994) J. Biol. Chem. 269, 8659–8666]. The factors involved in the effect of cAMP on synthesis of Dol-PP-oligosaccharide are investigated here. The GlcNAc transfer to dolichol phosphate (Dol-P) was found to be unaffected by pretreatment with 8-bromo-cAMP. By measuring the uptake of [3H]mevalonate, a 20-fold increase in the incorporation of the label into Dol-P was observed in the cells treated with 8-bromo-cAMP. Under the same conditions, the synthesis of dolichol was enhanced 60-fold. However, the incorporation of the radioactivity into cholesterol was not increased in the JEG-3 cells pretreated with 8-bromo-cAMP, which suggests a specific stimulation of the dolichol/Dol-P pathway by cAMP. The cis-prenyltransferase activity was found to be increased 10-fold in cells pretreated with 8-bromo-cAMP. Dolichol kinase activity was unaffected by stimulation with 8-bromo-cAMP. The present study suggests that the larger glycosylation capacity in JEG-3 cells treated with 8-bromo-cAMP is caused by an increase in the microsomal cis-prenyltransferase activity.

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Long-term effect of low frequency stimulation of STN on dysphagia, freezing of gait and other motor symptoms in PD

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp-2018-318060 ◽

2018 ◽

Vol 89 (9) ◽

pp. 989-994 ◽

Cited By ~ 18

Author(s):

Tao Xie ◽

Lisa Bloom ◽

Mahesh Padmanaban ◽

Breanna Bertacchi ◽

Wenjun Kang ◽

...

Keyword(s):

Rating Scale ◽

Freezing Of Gait ◽

Term Effect ◽

Double Blind Study ◽

Motor Symptoms ◽

Swallowing Function ◽

Long Term Effect ◽

Swallowing Difficulty ◽

Stimulation Of

ObjectiveTo evaluate the long-term effect of 60 Hz stimulation of the subthalamic nucleus (STN) on dysphagia, freezing of gait (FOG) and other motor symptoms in patients with Parkinson’s disease (PD) who have FOG at the usual 130 Hz stimulation.MethodsThis is a prospective, sequence randomised, crossover, double-blind study. PD patients with medication refractory FOG at 130 Hz stimulation of the STN were randomised to the sequences of 130 Hz, 60 Hz or deep brain stimulation off to assess swallowing function (videofluoroscopic evaluation and swallowing questionnaire), FOG severity (stand–walk–sit test and FOG questionnaire) and motor function (Unified PD Rating Scale, Part III motor examination (UPDRS-III)) at initial visit (V1) and follow-up visit (V2, after being on 60 Hz stimulation for an average of 14.5 months), in their usual medications on state. The frequency of aspiration events, perceived swallowing difficulty and FOG severity at 60 Hz compared with 130 Hz stimulation at V2, and their corresponding changes at V2 compared with V1 at 60 Hz were set as primary outcomes, with similar comparisons in UPDRS-III and its subscores as secondary outcomes.ResultsAll 11 enrolled participants completed V1 and 10 completed V2. We found the benefits of 60 Hz stimulation compared with 130 Hz in reducing aspiration frequency, perceived swallowing difficulty, FOG severity, bradykinesia and overall axial and motor symptoms at V1 and persistent benefits on all of them except dysphagia at V2, with overall decreasing efficacy when comparing V2 to V1.ConclusionsThe 60 Hz stimulation, when compared with 130 Hz, has long-term benefits on reducing FOG, bradykinesia and overall axial and motor symptoms except dysphagia, although the overall benefits decrease with long-term use.Clinical trial registrationNCT02549859; Pre-results.

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