QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, April 19, 2006, 26(16):4426-4436; doi:10.1523/JNEUROSCI.5298-05.2006

This Article Full Text Full Text (PDF) Supplemental data Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Hirata, A. Articles by Castro-Alamancos, M. A. Search for Related Content PubMed PubMed Citation Articles by Hirata, A. Articles by Castro-Alamancos, M. A. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB CARBACHOL CHLORIDE

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Noradrenergic Activation Amplifies Bottom-Up and Top-Down Signal-to-Noise Ratios in Sensory Thalamus

Akio Hirata, Juan Aguilar, and Manuel A. Castro-Alamancos

Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129

Correspondence should be addressed to Dr. Manuel A. Castro-Alamancos, Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129. Email: mcastro{at}drexelmed.edu

Thalamocortical cells receive sensory signals via primary sensory afferents and cortical signals via corticothalamic afferents. These signals are influenced by a variety of neuromodulators that are released in the thalamus during specific behavioral states. Hence, different neuromodulators may set different thalamic modes of sensory information processing. We found that noradrenergic activation affects sensory and corticothalamic signals in the whisker thalamus differently than cholinergic activation. Whereas cholinergic activation increases the spontaneous firing (noise) and enlarges the receptive fields of ventroposterior medial thalamus (VPM) cells, noradrenergic activation decreases spontaneous firing and focuses receptive fields. Consequently, for sensory signals, noradrenergic activation sets bottom-up thalamic processing to a focused and noise-free excitatory receptive field, which contrasts with the broad and noisy excitatory receptive field characteristic of cholinergic activation. For corticothalamic signals, noradrenergic activation sets top-down processing to a noise-free high-frequency signal detection mode, whereas cholinergic activation produces a noisy broadband signal detection mode. The effects of noradrenergic activation on signal-to-noise ratios of VPM cells were found to be mediated by nucleus reticularis thalamic (nRt) cells. Hence, a major role of nRt cells is to regulate the noise level of thalamocortical cells during sensory processing. In conclusion, different modulators establish distinct modes of bottom-up and top-down information processing in the sensory thalamus.

Key words: thalamus; vibrissas; sensory processing; vigilance; attention; locus ceruleus; brainstem reticular formation; acetylcholine; norepinephrine; corticothalamic

---

Received Dec. 12, 2005; revised March 19, 2006; accepted March 20, 2006.

Correspondence should be addressed to Dr. Manuel A. Castro-Alamancos, Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129. Email: mcastro{at}drexelmed.edu

This article has been cited by other articles:

				A. Hirata, J. Aguilar, and M. A. Castro-Alamancos Influence of Subcortical Inhibition on Barrel Cortex Receptive Fields J Neurophysiol, July 1, 2009; 102(1): 437 - 450. [Abstract] [Full Text] [PDF]

				Y.-W. Lam and S. M. Sherman Functional Organization of the Somatosensory Cortical Layer 6 Feedback to the Thalamus Cereb Cortex, May 15, 2009; (2009) bhp077v1. [Abstract] [Full Text] [PDF]

				L. K. Bekar, W. He, and M. Nedergaard Locus Coeruleus {alpha}-Adrenergic-Mediated Activation of Cortical Astrocytes In Vivo Cereb Cortex, December 1, 2008; 18(12): 2789 - 2795. [Abstract] [Full Text] [PDF]

				J. D. Cohen, A. Hirata, and M. A. Castro-Alamancos Vibrissa Sensation in Superior Colliculus: Wide-Field Sensitivity and State-Dependent Cortical Feedback J. Neurosci., October 29, 2008; 28(44): 11205 - 11220. [Abstract] [Full Text] [PDF]

				M. A. Starr, M. E. Page, and B. D. Waterhouse MDMA (3,4-Methylenedioxymethamphetamine)-Mediated Distortion of Somatosensory Signal Transmission and Neurotransmitter Efflux in the Ventral Posterior Medial Thalamus J. Pharmacol. Exp. Ther., October 1, 2008; 327(1): 20 - 31. [Abstract] [Full Text] [PDF]

				G. Foffani, J. K. Chapin, and K. A. Moxon Computational Role of Large Receptive Fields in the Primary Somatosensory Cortex J Neurophysiol, July 1, 2008; 100(1): 268 - 280. [Abstract] [Full Text] [PDF]

				A. Hirata and M. A. Castro-Alamancos Cortical Transformation of Wide-Field (Multiwhisker) Sensory Responses J Neurophysiol, July 1, 2008; 100(1): 358 - 370. [Abstract] [Full Text] [PDF]

				J. D. Cohen and M. A. Castro-Alamancos Early Sensory Pathways for Detection of Fearful Conditioned Stimuli: Tectal and Thalamic Relays J. Neurosci., July 18, 2007; 27(29): 7762 - 7776. [Abstract] [Full Text] [PDF]

				P. Rigas and M. A. Castro-Alamancos Thalamocortical Up States: Differential Effects of Intrinsic and Extrinsic Cortical Inputs on Persistent Activity J. Neurosci., April 18, 2007; 27(16): 4261 - 4272. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help