Parasagittal स्लाइस के कृंतक औसत दर्जे entorhinal प्रांतस्था संगठन पृष्ठीय उदर की जांच के लिए तैयार
Summary
हम तैयार करने के लिए और मस्तिष्क स्लाइसें कि औसत दर्जे का entorhinal प्रांतस्था (MEC) अक्ष पृष्ठीय उदर को बनाए रखने से electrophysiological रिकॉर्डिंग प्रक्रिया का वर्णन करता है. क्योंकि स्थान की तंत्रिका एन्कोडिंग MEC पृष्ठीय – उदर के भीतर एक संगठन इस प्रकार, इन प्रक्रियाओं सेलुलर नेविगेशन और स्मृति के लिए महत्वपूर्ण तंत्र की जांच की सुविधा.
Abstract
Computation in the brain relies on neurons responding appropriately to their synaptic inputs. Neurons differ in their complement and distribution of membrane ion channels that determine how they respond to synaptic inputs. However, the relationship between these cellular properties and neuronal function in behaving animals is not well understood. One approach to this problem is to investigate topographically organized neural circuits in which the position of individual neurons maps onto information they encode or computations they carry out1. Experiments using this approach suggest principles for tuning of synaptic responses underlying information encoding in sensory and cognitive circuits2,3.
The topographical organization of spatial representations along the dorsal-ventral axis of the medial entorhinal cortex (MEC) provides an opportunity to establish relationships between cellular mechanisms and computations important for spatial cognition. Neurons in layer II of the rodent MEC encode location using grid-like firing fields4-6. For neurons found at dorsal positions in the MEC the distance between the individual firing fields that form a grid is on the order of 30 cm, whereas for neurons at progressively more ventral positions this distance increases to greater than 1 m. Several studies have revealed cellular properties of neurons in layer II of the MEC that, like the spacing between grid firing fields, also differ according to their dorsal-ventral position, suggesting that these cellular properties are important for spatial computation2,7-10.
Here we describe procedures for preparation and electrophysiological recording from brain slices that maintain the dorsal-ventral extent of the MEC enabling investigation of the topographical organization of biophysical and anatomical properties of MEC neurons. The dorsal-ventral position of identified neurons relative to anatomical landmarks is difficult to establish accurately with protocols that use horizontal slices of MEC7,8,11,12, as it is difficult to establish reference points for the exact dorsal-ventral location of the slice. The procedures we describe enable accurate and consistent measurement of location of recorded cells along the dorsal-ventral axis of the MEC as well as visualization of molecular gradients2,10. The procedures have been developed for use with adult mice (> 28 days) and have been successfully employed with mice up to 1.5 years old. With adjustments they could be used with younger mice or other rodent species. A standardized system of preparation and measurement will aid systematic investigation of the cellular and microcircuit properties of this area.
Protocol
Discussion
MEC सर्किट गुण है कि एक संगठन पृष्ठीय उदर हम यहाँ विस्तार में एक parasagittal टुकड़ा तैयारी है कि MEC की हद पृष्ठीय उदर को बरकरार रखता है के उत्पादन के लिए एक प्रक्रिया का वर्णन किया है का पालन करें की जांच की सुविधा….
Divulgations
The authors have nothing to disclose.
Acknowledgements
हम उनके समर्थन के लिए धन्यवाद निम्नलिखित: राष्ट्रमंडल छात्रवृत्ति आयोग (एचपी) ब्रिटेन धन, EPSRC (हिमाचल प्रदेश), बीबीएसआरसी (MFN) और यूरोपीय संघ मैरी क्यूरी क्रिया (MFN).
Materials
| Cutting ACSF(mM) | Standard ACSF(mM) | Internal solution (mM) | CASNumber | Supplier Catalogue Number | |
| NaCl | 86 | 124 | 7647-14-5 | Sigma S9888 | |
| NaH2PO4 | 1.2 | 1.2 | 13472-35-0 | Sigma 71505 | |
| KCl | 2.5 | 2.5 | 10 | 7447-40-7 | Sigma P3911 |
| NaHCO3 | 25 | 25 | 144-55-8 | Fischer S/4240 | |
| Glucose | 25 | 20 | 50-99-7 | Sigma G5767 | |
| Sucrose | 75 | 57-50-1 | Sigma S5016 | ||
| CaCl2 | 0.5 | 2 | 10043-52-4 | VWR 190464K | |
| MgCl2 | 7 | 1 | 2 | 7786-30-3 | Sigma 63020 |
| K Gluconate | 130 | 299-27-4 | Sigma G4500 | ||
| HEPES | 10 | 7365-45-9 | Sigma H3375 | ||
| EGTA | 0.1 | 67-42-5 | Sigma E4378 | ||
| Na2ATP | 2 | 34369-07-8 | Sigma A7699 | ||
| Na2GTP | 0.3 | 36051-31-7 | Sigma G8877 | ||
| NaPhospho-Creatine | 10 | 19333-65-4 | Sigma P7936 | ||
| Biocytin (optional) | 2.7 | 576-19-2 | Sigma B4261 |
Table 1. Cutting ACSF, standard ACSF and K-Gluconate internal solution recipes.
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