Nursing-induced somatosensory cortex plasticity: temporally decoupled changes in neuronal receptive field properties are accompanied by modifications in activity-dependent protein expression.
نویسندگان
چکیده
This study is an attempt to gain insight into the malleability of representational maps in the primary somatosensory cortex in relation to the expression of proteins involved in inhibitory and excitatory neurotransmitter systems that contribute to maintain these maps in a dynamic state. Malleability of somatosensory maps is characterized by changes in the sizes of neuron receptive fields (RFs) affecting the representational grain and in the locations and submodalities of these RFs modifying the map extent. The concomitance of these alterations remains so far hypothetical. We used nursing as an evolving source of ethologically significant cutaneous stimulation. This cyclic behavior is particularly suited to investigating the time course of experience-dependent cortical changes. Electrophysiological maps of the ventrum skin were recorded twice in the same lactating rats between nursing initiation and several weeks after nursing. We found that reduction in RF size occurred earlier than map expansion. As nursing time declined, the map expansion was maintained longer than the RF sharpening. Based on this difference in time course, we compared the expression patterns of several activity-dependent proteins in relation to the RF plasticity. Western blot analysis showed an increase in glutamic acid decarboxylase expression that was concomitant with RF contraction. In contrast, NR2A subunit of NMDA and alpha calcium/calmodulin kinase type II were upregulated at times when map expansion was observed. We propose that inhibitory and excitatory plasticity mechanisms operating with different time courses may contribute to the temporal dissociation of nursing-induced RF reshaping and map expansion.
منابع مشابه
Neuronal response properties of somatosensory cortex (layer IV) are modulated following experience dependent plasticity in c-fiber depleted rats
Previous studies have shown that the receptive field properties, spontaneous activity and spatio-temporal interactions of low-threshold mechanical somatosensory cells in the barrel cortex are influenced by C-fibers. In this study, we examined the effect of C-fiber depletion on response properties of barrel cortex neurons following experience dependent plasticity. Methods: In this study, exte...
متن کاملEffect of Norepinephrine depletion on induction of experience dependent plasticity in male rat barrel cortex
Introduction: Barrel cortex of rats is a part of somatosensory cortex, which receives information from facial whiskers. Vibrisectomy by sensory deprivation leads to some changes in the barrel cortex, which have been known as experience dependent plasticity. On the other hand, Norepinephrine (NE) and locus coeruleus, which is the main source of NE, influenced response properties of cortical bar...
متن کاملEffects of Neonatal C-Fiber Depletion on Interaction between Neocortical Short-Term and Long-Term Plasticity
Introduction: The primary somatosensory cortex has an important role in nociceptive sensory-discriminative processing. Altered peripheral inputs produced by deafferentation or by long-term changes in levels of afferent stimulation can result in plasticity of cortex. Capsaicin-induced depletion of C-fiber afferents results in plasticity of the somatosensory system. Plasticity includes short-term...
متن کاملShort exposure to an enriched environment accelerates plasticity in the barrel cortex of adult rats
Cortical sensory neurons adapt their response properties to use and disuse of peripheral receptors in their receptive field. Changes in synaptic strength can be generated in cortex by simply altering the balance of input activity, so that a persistent bias in activity levels modifies cortical receptive field properties. Such activity-dependent plasticity in cortical cell responses occurs in rat...
متن کاملNeuronal response properties of somatosensory cortex (layer IV) are modulated following experience dependent plasticity in c-fiber depleted rats
Introduction: Previous studies have shown that the receptive field properties, spontaneous activity and spatio-temporal interactions of low-threshold mechanical somatosensory cells in the barrel cortex are influenced by C-fibers. In this study, we examined the effect of C-fiber depletion on response properties of barrel cortex neurons following experience dependent plasticity. Methods: In this ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of neuroscience : the official journal of the Society for Neuroscience
دوره 26 42 شماره
صفحات -
تاریخ انتشار 2006