Auditory Thalamus Neurons During Sleep: Changes in Frequency Selectivity, Threshold, and Receptive Field Size
Laboratoire de Neurobiologie de l'Apprentissage, de la Mémoire et de la Communication, UMR 8620, Centre National de la Recherche Scientifique et Université Paris-Sud, 91405 Orsay Cedex, France Edeline, Jean-Marc, Yves Manunta, and Elizabeth Hennevin. Auditory Thalamus Neurons During Sleep: Chan...
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Published in | Journal of neurophysiology Vol. 84; no. 2; pp. 934 - 952 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
Am Phys Soc
01.08.2000
American Physiological Society |
Subjects | |
Online Access | Get full text |
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Summary: | Laboratoire de Neurobiologie de l'Apprentissage, de la
Mémoire et de la Communication, UMR 8620, Centre National de
la Recherche Scientifique et Université Paris-Sud, 91405 Orsay
Cedex, France
Edeline, Jean-Marc,
Yves Manunta, and
Elizabeth Hennevin.
Auditory Thalamus Neurons During Sleep: Changes in Frequency
Selectivity, Threshold, and Receptive Field Size. J. Neurophysiol. 84: 934-952, 2000. The present
study describes how the frequency receptive fields (RF) of auditory
thalamus neurons are modified when the state of vigilance of an
unanesthetized animal naturally fluctuates among wakefulness (W),
slow-wave sleep (SWS), and paradoxical sleep (PS). Systematic
quantification of several RF parameters including strength of the
evoked responses, response latency, acoustic threshold, shape of
rate-level function, frequency selectivity, and RF size was performed
while undrugged, restrained guinea pigs presented spontaneous alternances of W, SWS, and PS. Data are from 102 cells recorded during
W and SWS and from 53 cells recorded during W, SWS, and PS. During SWS,
thalamic cells behaved as an homogeneous population: as compared with
W, most of them (97/102 cells) exhibited decreased evoked spike rates.
The frequency selectivity was enhanced and the RF size was reduced. In
contrast during PS, two populations of cells were identified: one
(32/53 cells) showed the same pattern of changes as during SWS, whereas
the other (21/53 cells) expressed values of evoked spike rates and RF
properties that did not significantly differ from those in W. These two
populations were equally distributed in the different anatomical
divisions of the auditory thalamus. Last, during both SWS and PS, the
responses latency was longer and the acoustic threshold was higher than
in W but the proportion of monotonic versus nonmonotonic rate-level
functions was unchanged. During both SWS and PS, no relationship was
found between the changes in burst percentage and the changes of the RF
properties. These results point out the dual aspect of sensory
processing during sleep. On the one hand, they show that the auditory
messages sent by thalamic cells to cortical neurons are reduced both in terms of firing rate at a given frequency and in terms of frequency range. On the other hand, the fact that the frequency selectivity and
the rate-level function are preserved suggests that the messages sent
to cortical cells are not deprived of informative content, and that the
analysis of complex acoustic sounds should remain possible. This can
explain why, although attenuated, reactivity to biologically relevant
stimuli is possible during sleep. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0022-3077 1522-1598 |
DOI: | 10.1152/jn.2000.84.2.934 |