ABSTRACT
Objective To study the effects of transcranial magnetic stimulation (TMS) on learning and memory, and angiogenesis and the dendritic structure of hippocampal CA3 pyramidal neurons after cerebral infarction. Methods Forty-eight male Sprague-Dawley rats were divided into a sham operated group, a model group and a TMS group (n = 16). Rat models of focal cerebral infarction were established with unilateral middle cerebral artery (MCA) suture occlusion in the model and TMS groups. The rats of the TMS group were given 4 weeks of TMS treatment beginning 1 day after the infarction (2 times per day, 30 pulses per time). Their learning and memory abilities were tested with a Y-maze. Angiogenesis and the dendritic structure of their hippocampal CA3 pyramidal neurons were detected after 4 weeks. Results Compared with the model group, learning and memory improved significantly in the TMS group. The average microvessel density of the hippocampus in the TMS group was significantly more than in the model group. The total length of apical dendrites of hippocampal CA3 pyramidal neurons in TMS group was significantly longer than in the model group. Conclusions The improved learning and memory observed following TMS treatment are likely to be related to changes in angiogenesis, the dendritic.structure of the hippocampal CA3 pyramidal neurons, and enhanced synaptic plasticity.
ABSTRACT
Objective To investigate the alteration of phosphorylated GluR1Ser831 and behavioural effects in a rat model of levodopa-induced motor complications after Ca2 +/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) inhibitor KN-93 treatment. Methods The hemi-parkinsonian rat model was produced by injecting stereotaxically 6-OHDA to right medial forebrain bundle. Then, rats were intraperitoneally treated with levodopa ( 50 mg/kg with benserazide 12.5 mg/kg,twice daily) for 22 days. On day 23 ,rats received KN-93 before levodopa administration. Rotational duration was estimated. After sacrificed, subcellualr distribution of GluR1 and phosphorylated GluR1Ser831 were observed by western blot. Results The study showed that CaMKⅡ inhibitor KN-93 prolonged rotational duration. Moreover, KN-93 could regulate subcellular distribution of GluR1 and reduce hyperphosphorylation of GluR1 Ser831, which was closely associated with levodopa-induced motor complications. The expression of membrane GluR1 and phosphorylated GluR1Ser831 was (83.4 ±4.2)% and (47.2 ±5.2)% ,respectively. Conclusions These results indicated that activation of CaMKⅡ contributed to development of motor complications, through a mechanism that involved an increase in phosphorylated GluR1 Ser831. Pharmaceuticals which act to inhibit CaMKⅡ may be useful in the treatment of the motor complications in parkinsonian patients.