title: Effects of carbachol on lead-induced impairment of the long-term potentiation/depotentiation in rat dentate gyrus in vivo.
abstract: The present study aims at evaluating the impairment of LTP and depotentiation (DP) of LTP induced by acute lead exposure, and the effects of peripheral carbachol (CCh) application on LTP/DP of acute and chronic lead-exposed rats in dentate gyrus in vivo. Rats (80-100 days) were acutely exposed to lead by intraperitoneal injection of 0.2% lead acetate (PbAc) solution (1.5mg/100g) and/or CCh (1 micro g/100g). Rats were chronically exposed to lead from parturition through adulthood (80-100 days) by the drinking of 0.2% PbAc solution and/or CCh (1 micro g/100g) chronic intraperitoneal injection one week. The input-output (I/O) function, paired-pulse reaction (PPR), excitatory postsynaptic potential (EPSP) and population spike (PS) amplitude were measured in response to stimulation applied to the lateral perforant path. Results showed that: first, acute lead exposure significantly depressed the amplitudes of LTP/DP of both EPSP slope and PS amplitude. Second, CCh significantly increased the amplitudes of both EPSP LTP/DP and PS LTP of acute Pb-exposed rats. After CCh treatment, the magnitudes of EPSP LTP/DP and PS LTP of acute Pb-exposed rats showed no significant difference with controls. Third, Chronic CCh application also reversed chronic Pb-induced impairment of PS LTP and EPSP DP of LTP. As CCh does not cross blood-brain barrier in healthy animals, the data suggest that CCh may traverse BBB in Pb-exposed animals and cure Pb-induced dysfunction of learning and memory.
authors.affiliation: Department of Neurobiology and Biophysics, School of Life Sciences, University of Science and Technology of China, 96, Jinzhai Road, Hefei, Anhui, PR China.
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Wei-Heng
authors.initials: WH
authors.lastname: Chen
authors.forename: Da-Miao
authors.initials: DM
authors.lastname: Zhu
authors.forename: Jia-Qi
authors.initials: JQ
authors.lastname: She
authors.forename: Di-Yun
authors.initials: DY
authors.lastname: Ruan
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002217:Carbachol / Q000008:administration & dosage*; D018679:Cholinergic Agonists / Q000008:administration & dosage*; D018891:Dentate Gyrus / Q000187:drug effects* / Q000502:physiology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D007274:Injections, Intraperitoneal; D017774:Long-Term Potentiation / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009498:Neurotoxins; D009942:Organometallic Compounds; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018679:Cholinergic Agonists; D009498:Neurotoxins; D009942:Organometallic Compounds; D002217:Carbachol; C008261:lead acetate