Changes possibly induced by 3-NP in electrophysiological functional characteristics
of the central nervous system are, in contrast to biochemical and morphological alterations,
less well known. In this study, the usability of a standard neurophysiological investigation
system to detect functional changes caused by 3-NP administration in rats was studied.
In subacute treatment, 10 or 15 mg/kg 3-NP was given i.p. on five consecutive days
to groups of 10 rats and the effects were checked 4 weeks later. Acutely treated rats
received 20 mg/kg i.p. after several control records. For recording, the animals'
left hemisphere was exposed in urethane anesthesia. Silver electrodes were placed
on the cortical sensory foci and tungsten needles in the subcortical (caudatum, globus
pallidus) recording sites. Spontaneous electrical activity, as well as somatosensory,
visual and auditory evoked potentials, were recorded. Following subacute treatment,
the slowest (theta) and fastest (beta2 and gamma) frequencies of the spontaneous activity
were changed, differently in the cortical versus subcortical sites. In the sensory
evoked potentials after subacute treatment, an increase of the latency was seen in
all sensory areas. In the acutely treated animals, the amplitude of the somatosensory
evoked potential decreased after giving 3-NP. With double stimuli, the relation of
the two responses was treatment- and interval-dependent. Understanding the mechanism
of these effects may widen the knowledge base for using 3-NP in disease models. ÂŠ
2005 Elsevier B.V. All rights reserved.