INVESTIGADORES
KASANETZ Fernando
artículos
Título:
Spreading of slow cortical rhythms to the basal ganglia output nuclei in rats with nigrostriatal lesions.
Autor/es:
MARIANO A. BELLUSCIO; FERNANDO KASANETZ; LUIS A. RIQUELME ANDM. GUSTAVO MURER
Revista:
EUROPEAN JOURNAL OF NEUROSCIENCE
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2003 vol. 17 p. 1046 - 1052
ISSN:
0953-816X
Resumen:
A high proportion of neurons in the basal ganglia display rhythmic burst
firing after chronic nigrostriatal lesions. For instance, the periodic
bursts exhibited by certain striatal and subthalamic nucleus neurons in
6-hydroxydopamine-lesioned rats seem to be driven by the ∼ 1 Hz
high-amplitude rhythm that is prevalent in the cerebral cortex of
anaesthetized animals. Because the striatum and subthalamic nucleus are
the main afferent structures of the substantia nigra pars reticulata, we
examined the possibility that the low-frequency modulations (periodic
bursts) that are evident in approximately 50% nigral pars reticulata
neurons in the parkinsonian condition were also coupled to this slow
cortical rhythm. By recording the frontal cortex field potential
simultaneously with single-unit activity in the substantia nigra pars
reticulata of anaesthetized rats, we proved the following. (i) The
firing of nigral pars reticulata units from sham-lesioned rats is not
coupled to the ∼ 1 Hz frontal cortex slow oscillation. (ii)
Approximately 50% nigral pars reticulata units from
6-hydroxydopamine-lesioned rats oscillate synchronously with the ∼ 1 Hz
cortical rhythm, with the cortex leading the substantia nigra by
∼ 55 ms; the remaining ∼ 50% nigral pars reticulata units behave as the
units recorded from sham-lesioned rats. (iii) Periodic bursting in
nigral pars reticulata units from 6-hydroxydopamine-lesioned rats is
disrupted by episodes of desynchronization of cortical field potential
activity. Our results strongly support that nigrostriatal lesions
promote the spreading of low-frequency cortical rhythms to the
substantia nigra pars reticulata and may be of outstanding relevance for
understanding the pathophysiology of Parkinson's disease.