f***4
发帖数: 886 | 1 现在做LTP一般是在活体内还是在脑片上。在活体内难吗？请教有没有经典的文献。谢
谢 | i***R
发帖数: 663 | 2 我也比较外行。印象里LTP一般是在脑片上，很少能在活体上做细胞水平电生理的。虽
然德国有个组的确做到了直接在活动的老鼠脑部做电生理，但那技术是很难的。 | f***4
发帖数: 886 | 3 谢谢回复
那活体上直接做的（就是说不是细胞水平的），意义大吗。
看这片文献http://www.sciencemag.org/cgi/data/309/5743/2033/DC1/1
Electrophysiology. Tc1 and wild-type littermate mice, aged 4-8 months, were
anaesthetized with an intraperitoneal injection of urethane (1.8 g/kg). LTP
was investigated in the dentate gyrus using a concentric bipolar stimulating
electrode positioned in the perforant path (AP-level with Lamda, ML-3 mm
from midline, DV-1.5 mm) and a glass micropipette recording electrode
positioned in the hilus of the ipsilateral dentate gyrus (AP-2 mm posterior
to bregma, ML-1.6 mm from midline, DV-1.5 mm, with minor variation judged by
shape of response). Test responses were evoked using monophasic stimuli (0.
033 Hz; 70-300 μA, 60 μs). Using a wide range of stimulus intensities
input-output curves were generated plotting the average of three sampled
responses for each intensity. Prior to assessment of LTP pairs of pulses (
inter-pulse intervals, 10- 1000 ms) were used to study paired-pulse
facilitation of EPSP and population spike. EPSP slope facilitation was
studied using a stimulus intensity sufficient to drive a pure EPSP response
of around 1 mV. Population spike facilitation was studied using a higher
stimulus intensity sufficient to evoke a spike of approximately 1 mV. Three
responses were also averaged for each interpulse interval. To study LTP a
baseline stimulus intensity was selected sufficient to drive a spike of
approximately 1 mV and an EPSP slope approximately 40% of maximum. 40
baseline recordings were made over 20 min prior to applying a tetanic
stimulation, consisting of 6 series of 6 trains of 6 stimuli at 400 Hz, 200
ms between trains, 20 s between series. During the tetanus pulse width was
doubled. 120 further evoked recordings were then made at baseline frequency
and intensity over the course of the following hour. The slope of the field
excitatory postsynaptic potential (fEPSP) was used as an index of LTP and
expressed as a percentage change relative to the mean response in the final
10 min before tetanus. Data are given as mean ± SEM.
【在 i***R 的大作中提到】
: 我也比较外行。印象里LTP一般是在脑片上，很少能在活体上做细胞水平电生理的。虽
: 然德国有个组的确做到了直接在活动的老鼠脑部做电生理，但那技术是很难的。
| w********y
发帖数: 288 | 4 意义大不大跟具体研究的问题有关吧。活体实验一般能把生理机制跟行为功能直接联系
起来，笼统的讲比脑片意义大。反之，如果不直接研究生理功能，就简单的做一些电生
理数据测量，即便实验难度大，意义也有限。
were
LTP
stimulating
posterior
by
【在 f***4 的大作中提到】
: 谢谢回复
: 那活体上直接做的（就是说不是细胞水平的），意义大吗。
: 看这片文献http://www.sciencemag.org/cgi/data/309/5743/2033/DC1/1
: Electrophysiology. Tc1 and wild-type littermate mice, aged 4-8 months, were
: anaesthetized with an intraperitoneal injection of urethane (1.8 g/kg). LTP
: was investigated in the dentate gyrus using a concentric bipolar stimulating
: electrode positioned in the perforant path (AP-level with Lamda, ML-3 mm
: from midline, DV-1.5 mm) and a glass micropipette recording electrode
: positioned in the hilus of the ipsilateral dentate gyrus (AP-2 mm posterior
: to bregma, ML-1.6 mm from midline, DV-1.5 mm, with minor variation judged by
| s****0
发帖数: 2532 | |
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