RT Journal Article
T1 Neuron synchronization in the rat gracilis nucleus facilitates sensory transmission in the somatosensory pathway
A1 Makarov Slizneva, Valeriy
A1 Malmierca, Eduardo
A1 Castellanos, Nazareth P.
A1 Núñez-Medina, Alberto
A1 Núñez, Ángel
AB We have studied the role of the temporal correlation of multiple cell discharges in the facilitation of the somatosensory information transmission from the gracilis nucleus to the primary somatosensory (SI) cortex in anesthetized rats. Pairs of gracilis neurons or gracilis-SI cortical neurons were recorded during application of 20-ms tactile stimuli in control conditions and after electrical corticofugal stimulation. Cross-correlation of neural spike trains showed significant changes in synchronization of the neuron firing provoked by the corticofugal stimulation. To quantify the time-frequency alterations in the functional association within neuron pairs we used the wavelet coherence measure. We show that electrical stimulation of the SI cortex induces a short-lasting facilitation of tactile responses of projecting gracilis neurons if their receptive fields (RFs) overlap with the RF of the stimulated cortical area (matching condition). Moreover, synchronization of discharges of gracilis neurons with a common RF is increased by activation of the corticofugal projection. Synchronization is favored by a stimulus induced synchronous oscillatory activity of projecting neurons in the range 3-10 Hz. In the matching condition synchronous discharges in the gracilis increment the number of spikes elicited in the SI cortex. Thus the efficacy of the sensory transmission from the gracilis nucleus to the SI cortex is modulated by the corticofugal projection through two complementary mechanisms: (i) by changing the responsiveness (number of elicited spikes) of individual gracilis neurons; and (ii) by a dynamic consolidation of gracilis neurons with a common RF into microcircuits generating synchronous spikes.
PB Blackwell Publishing
SN 0953-816X
YR 2009
FD 2009-08
LK https://hdl.handle.net/20.500.14352/42343
UL https://hdl.handle.net/20.500.14352/42343
NO Spanish Ministry of Education and Science
NO Santander-Complutense
NO Mutua Madrileña Fundation
DS Docta Complutense
RD 4 abr 2025