Biochemical and behavioral effects of a sensorimotor cortex injury in rats pretreated with the noradrenergic neurotoxin DSP-4.
The role of the noradrenergic (NE) system in recovery of motor function after sensorimotor cortex (SMCX) injury was investigated. After training on a beam-walking task to assess changes in motor function, animals were given DSP-4 or saline and tested for 2 weeks; both groups then received unilateral SMCX suction ablations. Animals that received DSP-4 were significantly retarded in motor recovery compared with the saline group. At 24 days after injury (after motor recovery), the animals' deficits were significantly reinstated with NE-blocking drugs. DSP-4 significantly depressed NE levels in the hippocampus and cerebellum. A Timm histochemical analysis revealed glutamatergic sprouting in the hippocampus of animals that were pretreated with DSP-4, which suggests the possibility that similar glutamatergic plasticity in other pathways may occur and that excitotoxicity might also play a role after the DSP-4 induced NE deafferentation.
D018663:Adrenergic Agents / Q000494:pharmacology*; D000344:Afferent Pathways / Q000187:drug effects; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology*; D001931:Brain Mapping; D002531:Cerebellum / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology; D004292:Dominance, Cerebral / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009044:Motor Cortex / Q000187:drug effects*; D009048:Motor Skills / Q000187:drug effects*; D009412:Nerve Fibers / Q000187:drug effects; D009416:Nerve Regeneration / Q000187:drug effects; D009473:Neuronal Plasticity / Q000187:drug effects; D009638:Norepinephrine / Q000502:physiology*; D010643:Phenoxybenzamine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011941:Receptors, Adrenergic / Q000187:drug effects*; D017470:Receptors, Glutamate / Q000187:drug effects; D013003:Somatosensory Cortex / Q000187:drug effects*
D018663:Adrenergic Agents; D001596:Benzylamines; D011941:Receptors, Adrenergic; D017470:Receptors, Glutamate; D010643:Phenoxybenzamine; D003000:Clonidine; C012102:DSP 4; D009638:Norepinephrine