| Abstract: | The activity of neurons of the reticular portion of the substantia nigra before and after the microinjection of haloperidol
(25 μg/5 μl) into the head of the caudate nucleus on the ipsilateral side was investigated under chronic experimental conditions
in cats, using the extracellular microelectrode pickup technique. A significant (p<0.05) increase, from 34 to 61%, of neurons
with the burst type of spontaneous activity was established after the injection of haloperidol. A significant increase in
the ratio of the number of excitatory responses to inhibitory responses, from 0.04 to 0.4, was identified among the reactions
associated with saccadic eye movements following the microinjection of haloperidol. The number of orienting saccades in response
to the visual stimulus decreased against this background from 58 to 37%. The identified changes are regarded as a result of
the disinhibition of GABAergic neurons of the reticular portion of the substantia nigra under the influence of the blockade
of D2 dopamine receptors of the neostriatum.
Department of the Physiology of the Cerebral Cortex and Subcortical Structures, A. A. Bogomolets Institute of Physiology,
Academy of Sciences of Ukraine, Kiev. Translated from Fiziologicheskii Zhurnal irneni I. M. Sechenova, Vol. 80, No. 1, pp.
17–22, January, 1994. |
