ABSTRACT
The design of a miniature multichannel preamplifier for extracellular recordings of single unit activity in freely moving and swimming small animals is presented. The advantages of this design include perfect protection of the critical components and electric contacts from water. Thus, neuronal activity and EEG may be recorded differentially in any kinds of behavioral tasks including swimming in Morris water maze. Recordings are stable even if an animal is diving and swimming under the water surface. The reusable dismountable base can adopt different types of chronically implanted fine wire electrodes and movable arrays. Electrodes may be implanted to any desired depth. The assembly weight is less than 240 mg. Thus, the construction is light enough even for mice. This work is the first successful attempt for multichannel recording of neuronal activity in mice performing spatial task in Morris water maze.
Subject(s)
Electrodes, Implanted , Electroencephalography/methods , Extracellular Fluid/physiology , Miniaturization , Motor Activity/physiology , Swimming/physiology , Animals , Electroencephalography/instrumentation , Female , Male , Mice , Mice, Inbred C57BL , Rats , Rats, Long-EvansABSTRACT
The design of a removable miniature microdrive-headstage waterproof assembly for extracellular recordings of single unit activity with high-impedance electrodes in swimming mice is presented. The assembly provides perfect protection of the critical components and electric contacts from water. Neuronal activity may be recorded even if the animal is diving and swimming under the water surface. The advantages of this construction include simple installation and removal of the electrodes, rapid attachment of the assembly to the animal's skull, and rapid removal after recording. The device provides precise vertical positioning of the electrode without rotation or lateral shift, stable recordings of single units for several hours and the possibility to change the penetration track many times in the same animal. The assembly weight is less than 160mg. This work is the first successful attempt to record neuronal activity in mice performing spatial task in water maze.
Subject(s)
Action Potentials/physiology , Brain/physiology , Electrophysiology/methods , Neurons/physiology , Neurophysiology/methods , Animals , Electric Impedance , Electrodes/standards , Electrodes, Implanted/standards , Electrodes, Implanted/trends , Electroencephalography/instrumentation , Electroencephalography/methods , Electronics, Medical/methods , Electronics, Medical/standards , Electrophysiology/instrumentation , Extracellular Space/physiology , Female , Male , Maze Learning/physiology , Mice , Mice, Inbred C57BL , Neurophysiology/instrumentation , Physical Exertion/physiology , Swimming/physiologyABSTRACT
The design of a removable miniature microdrive-headstage assembly for extracellular recordings of single unit activity with high-impedance electrodes in freely moving small animals is presented. The advantages of this construction include simple installation and removal of the electrodes, rapid attachment of the assembly to the animal's skull and rapid removal after recording. The microdrive provides precise vertical positioning of the electrode without rotation or lateral shift, stable recordings of single units for several hours and the possibility to change the penetration track 5-10 times in the same animal. The microdrive permits microelectrode penetration to any desired depth. The small size of the microdrive permits installation of several units simultaneously. The assembly weight is less than 120mg.
