Electrophysiological Techniques for Studying Synaptic Activity In Vivo

Ross Jeggo1, Fei‐Yue Zhao1, David Spanswick2

1 Neurosolutions Limited, University of Warwick Medical School, Coventry, 2 University of Warwick Medical School, Coventry
Publication Name:  Current Protocols in Pharmacology
Unit Number:  Unit 11.11
DOI:  10.1002/0471141755.ph1111s64
Online Posting Date:  March, 2014
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Understanding the physiology, pharmacology, and plasticity associated with synaptic function is a key goal of neuroscience research and is fundamental to identifying the processes involved in the development and manifestation of neurological disease. A diverse range of electrophysiological methodologies are used to study synaptic function. Described in this unit is a technique for recording electrical activity from a single component of the central nervous system that is used to investigate pre‐ and post‐synaptic elements of synaptic function. A strength of this technique is that it can be used on live animals, although the effect of anesthesia must be taken into consideration when interpreting the results. This methodology can be employed not only in naïve animals for studying normal physiological synaptic function, but also in a variety of disease models, including transgenic animals, to examine dysfunctional synaptic plasticity associated with neurological pathologies. Curr. Protoc. Pharmacol. 64:11.11.1‐11.11.17. © 2014 by John Wiley & Sons, Inc.

Keywords: electrophysiology; hippocampus; CA1; LTP; in vivo

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Table of Contents

  • Introduction
  • Basic Protocol 1: Measurement of Population Spike Activity from the Ca1 Region of the Hippocampus in Anesthetized Rats Using Extracellular Recording Techniques: Sub‐Maximal LTP
  • Alternate Protocol 1: Measurement of Population Spike Activity from the Ca1 Region of the Hippocampus in Anesthetized Rats Using Extracellular Recording Techniques: Oligomeric Beta‐Amyloid‐Induced Deficits
  • Reagents and Solutions
  • Commentary
  • Literature Cited
  • Figures
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Basic Protocol 1: Measurement of Population Spike Activity from the Ca1 Region of the Hippocampus in Anesthetized Rats Using Extracellular Recording Techniques: Sub‐Maximal LTP

  • Sprague Dawley rat (male, 300 to 400 g)
  • 12% urethane (see recipe)
  • Normal saline (NS, see recipe)
  • Heparinized normal saline (see recipe)
  • 100% oxygen source
  • Mineral oil
  • Paraffin wax
  • Test substances, e.g., cycloserine
  • Pentobarbital sodium (see recipe)
  • Homeothermic blanket system and rectal probe (Harvard Apparatus)
  • Recommended surgical instruments:
    • Hemostatic clamp, straight (two are required)
    • Hemostatic clamp, curved
    • Large scissors
    • Medium blunt dissection scissors
    • Large blunt dissection forceps, curved
    • Small blunt dissection forceps, curved
    • Fine forceps (No. 5; two are required)
    • Arterial clip
    • Fine spring scissors
    • Scalpels
  • Stereomicroscope
  • Fiber‐optic light source
  • Polyethylene tubing (external/internal diameter 0.96/0.58 mm) for cannulation of femoral vein/artery
  • 26‐ and 30‐G syringe needles
  • Three‐way tap
  • Silicon tubing (external/internal diameter 3/2.4 mm) for cannulation of trachea
  • Stereotaxic frame (ST‐7, Narishige)
  • Vibration isolation table
  • Stereotaxic atlas for rat (Paxinos and Watson, )
  • Pressure transducer (Digitimer, cat. no. NL108T2)
  • A.C. preamplifier, filter and pressure amplifier modules (Digitimer, cat. nos. NL104, NL125, NL108)
  • Analog/digital converter (Micro1401, Cambridge Electronic Design)
  • NeuroLog modular acquisition hardware (NL905, NeuroLog, Digitimer)
  • Computer running Spike2 software (Cambridge Electronic Design)
  • Micro‐cautery device (Gemini, Harvard apparatus)
  • Q‐tips or cotton swabs
  • Hemostatic gelatin sponge
  • Surgical bone drill system
  • Single‐barrel carbon‐fiber recording electrode (Carbostar‐1, Kation Scientific)
  • Concentric bipolar stimulating electrode (FHC, cat. no. CBBPC75)
  • Micromanipulators (Narishige)
  • Headstage (Digitimer, cat. no. NL100AK)
  • Isolated constant‐voltage stimulator (DS2A, Digitimer)
  • Additional reagents and equipment for injection of rats (Donovan and Brown, )

Alternate Protocol 1: Measurement of Population Spike Activity from the Ca1 Region of the Hippocampus in Anesthetized Rats Using Extracellular Recording Techniques: Oligomeric Beta‐Amyloid‐Induced Deficits

  Additional Materials (also see protocol 1Basic Protocol)
  • Disease model agent: (beta‐amyloid; see recipe)
  • 2% (w/v) Chicago Sky Blue dye in normal saline (optional; see recipe for normal saline)
  • Stainless steel tubing for i.c.v. cannulation (Semat)
  • Syringe pump (Model 100, KD Scientific)
  • Stereotaxic frame bar‐mounted micromanipulator (Narishige)
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Literature Cited

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