title: Muscarinic cholinergic receptor binding in rat hindlimb somatosensory cortex following partial deafferentation by sciatic nerve transection.
abstract: Peripheral nerve injury or amputation leads to extensive changes within the central representations of the mammalian body surface. The mechanisms responsible for post-traumatic reorganization of these maps in adults may also, at least partly, underlie a more general feature of the somatosensory system--the capacity for stimulus-dependent plasticity. Acetylcholine has been implicated in both of these processes. We studied the binding of the ligands [3H]QNB and [3H]pirenzepine in rat hindlimb somatosensory cortex from 1 to 14 days following sciatic nerve transection. Although the [3H]QNB binding was not different from normal levels in tissue homogenates of the affected somatosensory cortex, differences were demonstrated when binding was measured on a layer-by-layer basis. [3H]QNB binding was changed only in certain layers, at certain times. The predominant effects appeared to be a decrease in binding in the middle layers from 4 to 14 days after the transection. Combining the [3H]QNB data with data obtained from the more M1-selective ligand [3H]pirenzepine suggested that complex changes occur among several muscarinic receptors, including receptors with non-M1 subtype characteristics. Moreover, unilateral nerve transection affects the hindlimb somatosensory regions in both hemispheres.
authors.affiliation: Paul-Flechsig-Institut für Hirnforschung, Abteilung für Neurochemie, Universität Leipzig, Germany.
authors.forename: U K
authors.initials: UK
authors.lastname: Hanisch
authors.forename: T
authors.initials: T
authors.lastname: Rothe
authors.forename: K
authors.initials: K
authors.lastname: Krohn
authors.forename: R W
authors.initials: RW
authors.lastname: Dykes
mesh_terms: D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D001345:Autoradiography; D001931:Brain Mapping; D007839:Functional Laterality; D006614:Hindlimb / Q000294:innervation*; D008297:Male; D010890:Pirenzepine / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000378:metabolism*; D012016:Reference Values; D012584:Sciatic Nerve / Q000502:physiology*; D013003:Somatosensory Cortex / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors; D014316:Tritium
chemical_list: D011976:Receptors, Muscarinic; D014316:Tritium; D010890:Pirenzepine; D011813:Quinuclidinyl Benzilate