A lightweight hybrid microdrive for use with awake unrestrained animals

A lightweight microdrive for single-unit recording in freely moving rats and pigeons

A design for an inexpensive and reliable subminiature microdrive for recording single neurons in the freely moving animal is presented. The Scribe microdrive is small and lightweight and has been used successfully to record in freely moving rats and pigeons. It would also be suitable for recording in mice. The device is simple and inexpensive yet allows for stable and precise manipulation of the recording electrodes. As a result it supports stable recordings conducted over long periods. Because the Scribe microdrive is a small-diameter device it is also suitable for multisite, multielectrode applications. Here we discuss the construction of the device and comment on its use in recording from freely moving rats and pigeons.

A low cost, high precision subminiature microdrive for extracellular unit recording in behaving animals

A new design for an inexpensive and reliable subminiature microdrive for unit recording in the freely moving animal is presented. The 'Scribe' microdrive is (a) of a small size and low weight, (b) allows for precise advancement of the electrodes, (c) permits stable unit recordings over time, (d) is simple to install, and (e) is economical to construct. These advantages are a result of its simple, single screw-based drive system and the ready availability of component parts. The Scribe microdrive is a small diameter device suitable for multi-site, multi-electrode applications.

A single-unit recording system, contact thermal probe and electromechanical stimulator for studying cellular mechanisms related to nociception at brain stem level of awake, freely moving rats

The purpose of this paper is to describe a simple, light-weight (3 g) device bearing a fine platinum-irridium Teflon-coated wire (50 microns) used to record single-unit activity extracellularly at brain stem level in the totally conscious freely moving rat. The up and down movements of the electrode through a guide cannula are insured by a small nut and a spring; the distance between the electrode and the end of the guide cannula is measured with a nut index. The system is directly connected to an amplifier (no FET or preamplifier) and allows for long term recordings necessary for a complete neuronal characterization and pharmacological experiments. The device is easy to make, entirely recoverable, and can be implanted from an animal to another. Further improvements are possible such as tungsten microelectrodes and telemetric or microinjection systems. In order to study some neuronal brain stem mechanisms involved in nociception, we have also designed a contact thermal probe and an electromechanical stimulator. The thermode is stuck to the shaved skin on the back of the rat, allowing heat pulses up to 51 degrees C to be applied. The mechanical stimulator is used manually and delivers reproducible innocuous stimuli to the skin. The fact that both types of stimulations are driven electrically enables the elaboration of cumulated peristimulus histograms which will reflect the neuronal activities in response to the application of noxious and non noxious stimuli.