Journal article
Different temporal processing of sensory inputs in the rat thalamus during quiescent and information processing states in vivo
The Journal of physiology, v 539(Pt 2), pp 567-578
01 Mar 2002
PMID: 11882688
Abstract
Sensory inputs from the whiskers reach the primary somatosensory thalamus through the medial lemniscus tract. The main role of the thalamus is to relay these sensory inputs to the neocortex according to the regulations dictated by behavioural state. Intracellular recordings in urethane-anaesthetized rats show that whisker stimulation evokes EPSP-IPSP sequences in thalamic neurons. Both EPSPs and IPSPs depress with repetitive whisker stimulation at frequencies above 2 Hz. Single-unit recordings reveal that during quiescent states thalamic responses to repetitive whisker stimulation are suppressed at frequencies above 2 Hz, so that only low-frequency sensory stimulation is relayed to the neocortex. In contrast, during activated states, induced by stimulation of the brainstem reticular formation or application of acetylcholine in the thalamus, high-frequency whisker stimulation at up to 40 Hz is relayed to the neocortex. Sensory suppression is caused by the depression of lemniscal EPSPs in relatively hyperpolarized thalamocortical neurons. Sensory suppression is abolished during activated states because thalamocortical neurons depolarize and the depressed lemniscal EPSPs are able to reach firing threshold. Strong IPSPs may also contribute to sensory suppression by hyperpolarizing thalamocortical neurons, but during activated states IPSPs are strongly reduced altogether. The results indicate that the synaptic depression of lemniscal EPSPs and the level of depolarization of thalamocortical neurons work together in thalamic primary sensory pathways to suppress high-frequency sensory inputs during non-activated (quiescent) states while permitting the faithful relay of high-frequency sensory information during activated (processing) states.
Metrics
Details
- Title
- Different temporal processing of sensory inputs in the rat thalamus during quiescent and information processing states in vivo
- Creators
- Manuel A Castro-Alamancos - Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A2B4, Canada. mcastro@bic.mni.mcgill.ca
- Publication Details
- The Journal of physiology, v 539(Pt 2), pp 567-578
- Publisher
- England
- Resource Type
- Journal article
- Language
- English
- Web of Science ID
- WOS:000174453400023
- Scopus ID
- 2-s2.0-0036522017
- Other Identifier
- 991014878160104721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Neurosciences
- Physiology