Juxtacellular Recordings Research Articles

A combined recording and microiontophoresis technique for input-output analysis of single neurons in the mammalian CNS

A method is described for producing electrolytically sharpened and lacquer-insulated steel microelectrodes and for their attachment to a multibarrel micropipet assembly by light-curing bonding compound. This electrode complex is specially designed for recordings from deep brain structures. It permits the analysis of the input signals to and the output signals from a single neuron recorded simultaneously from an extracellular electrode position, termed juxtacellular recording. Furthermore it provides the ability to manipulate pharmacologically the input-output ratio expressed by the neuron under varying sequences of natural stimulation.

Rubrally evoked unitary potentials in ventro-lateral thalamus of cat

The mechanism of rubrally evoked single unit potentials in ventro-lateral thalamus was explored by means of extra- and intracellular recording of neurons in cats anesthetized with Fluothane-nitrous oxide or Nembutal and paralyzed with Flaxedil. Unitary responses had a latency ranging from 0.8 to 500 msec. Bursts of spike responses coincided with crests of depolarization, more consistently after the first hyperpolarizing wave following the stimulus. Although spike potentials were usually associated with slow post-synaptic potentials, neither was necessary for the appearance of the other. The duration of inhibitory post-synaptic potentials ranged from 50 to 500 msec depending on the stimulus strength or number of pulses of the stimulating train. Some neurons displayed a capacity to follow frequencies of stimulation up to 100/sec. Fewer units could follow higher frequencies. There was a clear interdependence between cell response frequency, frequency of stimulation and strength of each individual pulse of the train. High sensitivity intra- or juxtacellular recording may reveal important interactive firing patterns between two very closely adjacent neurons. The functional significance of this interaction was discussed.