کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1920002 1535689 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Muscarinic cholinergic receptor subtypes in cerebral cortex of Fisher 344 rats: A light microscope autoradiography study of age-related changes
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی سالمندی
پیش نمایش صفحه اول مقاله
Muscarinic cholinergic receptor subtypes in cerebral cortex of Fisher 344 rats: A light microscope autoradiography study of age-related changes
چکیده انگلیسی

The density and localization of muscarinic cholinergic M1–M5 receptor subtypes was investigated in frontal and occipital cortex of male Fisher 344 rats aged 6 months (young-adult), 15 months (mature) and 22 months (senescent) by combined kinetic and equilibrium binding and light microscope autoradiography. In 6-month-old rats, the rank order density of muscarinic cholinergic receptor subtypes was M1 > M2 > M4 > M3 > M5 both in frontal and occipital cortex. A not homogeneous distribution of different receptor subtypes throughout cerebrocortical layers of frontal or occipital cortex was found. In frontal cortex silver grains corresponding to the M1 and M2 receptor subtypes were decreased in 15- and 22-month-old groups. The M3 receptor density was remarkably and moderately decreased in layers II/III and V, respectively, of rats aged 15 and 22 months. A reduced M4 receptor density was observed in layer I and to a lesser extent in layer V of mature and senescent rats, whereas no age-related changes of M5 receptor were found. In occipital cortex a diminution of M1 receptor was observed in layers II/III and V of mature and senescent rats. The M2 receptor expression decreased in layer I of 15- and 22-month-old senescent rats, whereas M3–M5 receptors were unchanged with exception of a slight decrease of the M4 receptor in layer IV and of M5 receptor in layers II/III. These findings indicate a different sensitivity to aging of muscarinic receptor subtypes located in various cerebrocortical layers. This may account for the difficulty in obtaining relevant results in manipulating cholinoceptors to counter age-related impairment of cholinergic system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Mechanisms of Ageing and Development - Volume 127, Issue 2, February 2006, Pages 115–122
نویسندگان
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