Experience-dependent plasticity of rat barrel cortex: redistribution of activity across barrel-columns.
The redistribution of neuronal activity across rat barrel cortex following an alteration in whisker usage has been investigated. In adult rats, two mystacial vibrissae - D(2) and one neighbor, D(1) or D(3) - were left intact while all other vibrissae on that side of the snout were clipped. Neurons in contralateral barrel cortex were sampled with a microelectrode array 3.5 days later. Stimulation of clipped vibrissae produced a narrow spatial distribution of cortical activity, whereas stimulation of intact vibrissae produced a widened spatial distribution. Simultaneous recordings from multiple cortical barrel-columns suggest that changes in the effective connectivity between barrel-columns may partially account for this redistribution of sensory responses. Evidence is also presented for a second mechanism, a release from inhibition in sensory-deprived cortical areas. A model is therefore proposed where these two mechanisms operate together to regulate the cortical distribution of evoked activity.
Lebedev
M A
MA
Cognitive Neuroscience Sector, International School for Advanced Studies, Via Beirut 9, 34014 Trieste.
Mirabella
G
G
Erchova
I
I
Diamond
M E
ME
D000200:Action Potentials / Q000502:physiology; D000222:Adaptation, Physiological; D000818:Animals; D004567:Electrodes, Implanted; D008297:Male; D008839:Microelectrodes; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D010812:Physical Stimulation; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time; D012683:Sensory Deprivation / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*; D014110:Touch / Q000502:physiology; D014738:Vibrissae / Q000294:innervation / Q000502:physiology