title: Unilateral whisker trimming in newborn rats alters neuronal coincident discharge among mature barrel cortex neurons.
abstract: It is known that sensory deprivation, including postnatal whisker trimming, can lead to severe deficits in the firing rate properties of cortical neurons. Recent results indicate that development of synchronous discharge among cortical neurons is also activity influenced, and that correlated discharge is significantly impaired following loss of bilateral sensory input in rats. Here we investigate whether unilateral whisker trimming (unilateral deprivation or UD) after birth interferes in the same way with the development of synchronous discharge in cortex. We measured the coincidence of spikes among pairs of neurons recorded under urethane anesthesia in one whisker barrel field deprived by trimming all contralateral whiskers for 60 days after birth (UD), and in untrimmed controls (CON). In the septal columns around barrels, UD significantly increased the coincident discharge among cortical neurons compared with CON, most notably in layers II/III. In contrast, synchronous discharge was normal between layer IV UD barrel neurons: i.e., not different from CON. Thus, while bilateral whisker deprivation (BD) produced a global deficit in the development of synchrony in layer IV, UD did not block the development of synchrony between neurons in layer IV barrels and increased synchrony within septal circuits. We conclude that changes in synchronous discharge after UD are unexpectedly different from those recorded after BD, and we speculate that this effect may be due to the driven activity from active commissural inputs arising from the contralateral hemisphere that received normal activity levels during postnatal development.
authors: Department of Psychology, Center for Integrative & Cognitive Neuroscience, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, Tennessee; Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee; ayan.ghoshal@vanderbilt.edu.
authors: Ayan
authors: A
authors: Ghoshal
authors: Department of Psychology, Center for Integrative & Cognitive Neuroscience, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, Tennessee;
authors: Brian
authors: B
authors: Lustig
authors: Chapel Hill, North Carolina.
authors: Maria
authors: M
authors: Popescu
authors: Department of Psychology, Center for Integrative & Cognitive Neuroscience, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, Tennessee;
authors: Ford
authors: F
authors: Ebner
authors: CM, INSERM UMRS 975, CNRS 7225, Université Pierre et Marie Curie, Paris, France;
authors: Pierre
authors: P
authors: Pouget
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005260:Female; D008297:Male; D009474:Neurons / Q000502:physiology*; D010812:Physical Stimulation; D051381:Rats; D020318:Rats, Long-Evans; D012683:Sensory Deprivation / Q000502:physiology*; D013003:Somatosensory Cortex / Q000254:growth & development / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology*; D014738:Vibrissae / Q000502:physiology
keywords: JPSTH; barrels; coincident discharge; rats; sensory deprivation; septa