کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9425645 | 1295885 | 2005 | 14 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Cocaine administration produces a protracted decoupling of neural and haemodynamic responses to intense sensory stimuli
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کلمات کلیدی
PLSAHbO2LDFVPMCSDHbRECoGCMRO2CBFBOLDOISNOSelectrocorticogram - الکتروکورتیکوگرافیcurrent source density - تراکم منبع فعلیfunctional magnetic resonance imaging - تصویرسازی تشدید مغناطیسی کارکردیfMRI - تصویرسازی تشدید مغناطیسی کارکردیcerebral blood flow - جریان خون مغزیtotal blood volume - حجم کل خونHBT - دگرباشان جنسیblood oxygen level dependent - سطح اکسیژن خون وابسته استlaser Doppler flowmetry - فلومتر Doppler لیزرcerebral metabolic rate of oxygen consumption - میزان متابولیسم مغزی مصرف اکسیژنNitric oxide - نیتریک اکسیدnitric oxide synthase - نیتریک اکسید سنتازbasal forebrain - پیشانی پایه
موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Evidence suggests that for relatively weak sensory stimuli, cocaine elevates background haemodynamic parameters but still allows enhanced neural responses to be reflected in enhanced haemodynamic responses. The current study investigated the possibility that for more intense stimuli, the raised background may produce a protracted attenuation of the haemodynamic response. Three experiments were performed to measure effects of i.v. cocaine administration (0.5 mg/kg) or saline on responses in rat barrel cortex to electrical stimulation of the whisker pad. The first experiment used optical imaging spectroscopy (OIS) and laser Doppler flowmetry (LDF) to measure haemodynamic changes. Cocaine caused an increase in baseline blood flow (peak approximately 90%), which lasted for the duration of the test period (25 min). Haemodynamic responses to whisker stimulation were substantially reduced throughout. The second experiment used a 16-channel multi-electrode to measure evoked potentials at 100 μm intervals through the barrel cortex. Summed neural responses (collapsed across the spatial dimension) after cocaine administration were similar to those after saline. The third experiment extended experiment 1 by examining the effects of cocaine on whisker sensory responses using functional magnetic resonance imaging (and concurrent OIS or LDF). Cocaine caused a similar increase in baseline and reduction in the evoked response to that seen in experiment 1. Together, the results of these three experiments show that cocaine produces a protracted decoupling of neural activity and haemodynamic responses to intense sensory stimulation, which suggests that imaging techniques based on changes in haemodynamic parameters may be unsuitable for studying the effects of cocaine on sensory processing in humans.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuroscience - Volume 132, Issue 2, 2005, Pages 361-374
Journal: Neuroscience - Volume 132, Issue 2, 2005, Pages 361-374
نویسندگان
J. Berwick, I.M. Devonshire, A.J. Martindale, D. Johnston, Y. Zheng, A.J. Kennerley, P.G. Overton, J.E.W. Mayhew,