INVESTIGADORES
KASANETZ Fernando
artículos
Título:
Cortical slow oscillatory activity is reflected in the membrane potential and spike trains of striatal neurons in rats with chronic nigrostriatal lesions
Autor/es:
KUEI Y TSENG; FERNANDO KASANETZ; LUCILA KARGIEMAN, LUIS A. RIQUELME, AND M. GUSTAVO MURER
Revista:
JOURNAL OF NEUROSCIENCE
Editorial:
SOC NEUROSCIENCE
Referencias:
Lugar: Washington; Año: 2001 vol. 21 p. 6430 - 6439
ISSN:
0270-6474
Resumen:
Neurons in the basal ganglia output nuclei display rhythmic burst firing
after chronic nigrostriatal lesions. The thalamocortical
network is a strong endogenous generator of
oscillatory activity, and the striatum receives a massive projection
from the
cerebral cortex. Actually, the membrane
potential of striatal projection neurons displays periodic shifts
between a very negative
resting potential (down state) and depolarizing
plateaus (up states) during which they can fire action potentials. We
hypothesized
that an increased excitability of striatal
neurons may allow transmission of cortical slow rhythms through the
striatum to
the remaining basal ganglia in experimental
parkinsonism. In vivo intracellular recordings revealed that
striatal projection neurons from rats with chronic nigrostriatal lesions
had a more
depolarized membrane potential during both the
down and up states and an increased firing probability during the up
events.
Furthermore, lesioned rats had significantly
fewer silent neurons than control rats. Simultaneous recordings of the
frontal
electrocorticogram and membrane potential of
striatal projection neurons revealed that the signals were oscillating
synchronously
in the frequency range 0.4?2 Hz, both in control
rats and rats with chronic nigrostriatal lesions. Spreading of the slow
cortical
rhythm is limited by the very low firing
probability of control rat neurons, but a slow oscillation is well
reflected in spike
trains of ∼60% of lesioned rat neurons. These
findings providein vivo evidence for a role of dopamine in controlling the flow of cortical activity through the striatum and may be of outstanding
relevance for understanding the pathophysiology of Parkinson's disease.