Reduction of GABAA receptor binding of [3H]muscimol in the barrel field of mice after peripheral denervation: transient and long-lasting effects.
The effect of peripheral sensory deprivation upon GABAA receptor binding of [3H]muscimol was investigated in the barrel cortex--cortical representation of mystacial vibrissae of mice--by means of in vitro quantitative autoradiography. Unilateral lesions of all vibrissae or selected rows of whiskers were performed neonatally or in adulthood. [3H]muscimol binding was examined after various survival times up to 60 days. Both types of lesions performed in adult mice resulted in a transient decrease (10-25%) of binding values in the deafferented areas of the barrel field as compared with the unoperated control side. Sixty days after denervation [3H]muscimol binding returned to control values. Similar results were found after neonatal removal of all vibrissae. Neonatal lesion of selected rows of vibrissae, however, resulted in a decrease of [3H]muscimol binding (by about 26%) lasting up to 60 days in corresponding rows of barrels. This last result was accompanied by severe cytoarchitectonic malformation of the barrel field. The results support the hypothesis that a decrease of inhibition plays a facilitatory role in the plastic reorganization of cortical circuitry.
Skangiel-Kramska
J
J
Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland.
Głazewski
S
S
Jabłońska
B
B
Siucińska
E
E
Kossut
M
M
D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001345:Autoradiography; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000378:metabolism*; D003714:Denervation; D051379:Mice; D009118:Muscimol / Q000493:pharmacokinetics*; D009473:Neuronal Plasticity / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D010525:Peripheral Nerves / Q000502:physiology*; D011963:Receptors, GABA-A / Q000378:metabolism*; D014738:Vibrissae / Q000502:physiology
D011963:Receptors, GABA-A; D009118:Muscimol