A low-noise preamplifier for multisite recording of brain multi-unit activity in freely moving animals

A novel FET instrumentation amplifier is described which, as compared to most traditional operational FET preamplifiers, is characterized by an about 7-10 times lower intrinsic electronic noise and a higher common mode rejection. This allows discrimination of single units from multi-unit recording, even if the action potential amplitudes are as small as 20-30 microV and the units are located more than 100 microns away from the electrode tips. Such a distant and chronic recording may be expected to reduce the possibility of mechanical interference with functions of neuronal membrane and its immediate environment, and may be suitable for studying changes in functional connectivities among neurons during the animal's behavior and learning.

[1]  C J Sherry,et al.  An inexpensive miniature preamplifier for monitoring electroencephalographic and extracellular action potentials in unrestrained animals. , 1975, Acta physiologica Academiae Scientiarum Hungaricae.

[2]  W. Rall.  Electrophysiology of a dendritic neuron model. , 1962, Biophysical journal.

[3]  M. Fuortes,et al.  Potentials recorded from the spinal cord with microelectrodes , 1955, The Journal of physiology.

[4]  P. G. Nelson,et al.  EXTRACELLULAR POTENTIAL FIELDS OF SINGLE SPINAL MOTONEURONS. , 1964, Journal of neurophysiology.

[5]  J. Krüger.  Simultaneous individual recordings from many cerebral neurons: techniques and results. , 1983, Reviews of physiology, biochemistry and pharmacology.

[6]  G. Buzsáki,et al.  Cellular bases of hippocampal EEG in the behaving rat , 1983, Brain Research Reviews.

[7]  Bruce L. McNaughton,et al.  The stereotrode: A new technique for simultaneous isolation of several single units in the central nervous system from multiple unit records , 1983, Journal of Neuroscience Methods.

[8]  T. Babb,et al.  A compact amplifier for extracellular recording. , 1971, Physiology & behavior.

[9]  Barry L. Jacobs,et al.  Activity of serotonin-containing neurons in the nucleus raphe pallidus of freely moving cats , 1982, Brain Research.

[10]  O. Prohaska,et al.  Multisite recording of brain field potentials and unit activity in freely moving rats , 1989, Journal of Neuroscience Methods.

[11]  R M Harper,et al.  A new microdrive for extracellular recording of single neurons using fine wires. , 1984, Electroencephalography and clinical neurophysiology.

[12]  D. Robinson,et al.  The electrical properties of metal microelectrodes , 1968 .

[13]  R. Llinás,et al.  The functional states of the thalamus and the associated neuronal interplay. , 1988, Physiological reviews.