Effects of paroxetine on protein kinase PKA, PKC and CaMKII activity in different brain regions in a rat depression model / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effects of paroxetine on protein kinase PKA, PKC and CaMKII activities in different brain regions in a rat model of depression.</p><p><b>METHODS</b>Thirty-six adult male SD rats were randomized into 6 groups, including one control group (I) and 5 groups of depression model established by forcing the rats to swim for 4 weeks. The 5 depression groups received no treatment (II) or were treated with paroxetine at a single dose (III), for a week (IV), 2 weeks (V) or 4 weeks (VI). The radioactivity of PKA, PKC and CaMKII in the hippocampus and prefrontal cortex was quantitatively measured using a liquid scintillation counter.</p><p><b>RESULTS</b>In the rat hippocampus, PKA and CaMKII activities were significantly lower in groups II, III, IV, and V than in groups I and VI (P<0.01 or P<0.05), but comparable between groups VI and I (P>0.05). PKC activity was significantly lower in group II than in group I (P<0.01), but showed no significant difference between the paroxetine-treated groups and group I (P>0.05). In the prefrontal cortex, the activity of PKA in groups I, II, III, and IV was similar (P>0.05), but all significantly lower than that in groups V and VI (P<0.01). PKC activity was significantly higher in groups II and III than that in group I and other paroxetine-treated groups (P<0.01), and similar between groups IV and I (P>0.05); groups V and VI had significantly lower PKC activity than group I (P<0.01). Group I had the highest CaMKII activity among the groups (P<0.01).</p><p><b>CONCLUSION</b>Chronic administration of paroxetine can reverse chronic stress-induced inhibition of PKA, PKC and CaMKII activity in rat hippocampus, while the effects of paroxetine on the protein kinases can be more complex in prefrontal cortex.</p>

Effect of naloxone on cognitive function in vascular dementia in rats.

BACKGROUND & OBJECTIVES: The endogenous opioid system plays an important role in cognitive functions and may also contribute to the progression of some kind of dementia. Naloxone has been shown to exert beneficial effects on memory deficits in patients with senile dementia and reverse some of the effects induced by endogeneous opioids. We therefore investigated the effects of naloxone on cognitive function in rats with vascular dementia (VD). METHODS: Vascular dementia was established by permanent occlusion of the common carotid arteries. Rats were divided into three groups viz., sham-operated controls, naloxone treated VD rats (naloxone 0.8 mg/kg, i.p. daily for 7 days), and nontreated VD rats. The Morris water maze test was performed to study spatial learning and memory. The extracellular recording technique was used to record long-term potentiation (LTP) of the Schaffer collateral-CA1 synapse in the rat hippocampal slices. RESULTS: In the hidden platform trials, escape latencies of the naloxone treated VD rats were significantly shorter than that of the nontreated VD rats (P < 0.001). In the probe trials, the number of enteries in the target area of the naloxone treated VD rats (8.36 +/- 1.38 times/min) were more than that of the nontreated VD rats (4.64 +/- 1.73 times/min) (P < 0.01). The magnitudes of LTP recorded in the CA1 pyramidal neurons of the naloxone treated VD rats were significantly augmented when compared to the nontreated VD rats (P < 0.05). INTERPRETATION & CONCLUSION: Naloxone could facilitate spatial learning and memory and enhance LTP in the CA1 region of hippocampus in rats with VD. It is postulated that naloxone might exert beneficial effects on cognitive function in VD in rats by modulating the synaptic plasticity in the hippocampal neuronal network.

Decreased treatment gap in epilepsy after intervention in five rural areas of China / 中华神经科杂志

Objective To evaluate the change of treatment gap of epilepsy after intervention in rural areas of China.Method Six months after being stopped from the intervention project in 2004,using the same method as the first survey at the baseline,a door-to-door epidemiological survey was conducted again in 5 rural areas where the intervention measures had been carried out for about 3 years.Results Three hundred and twenty cases of epilepsy were diagnosed in the total sample population,yielding a prevalence rate of 0.62% and the prevalence of active epilepsy 0.44%.The prevalence and the active prevalence of epilepsy in the survey in 2000 were 0.70% and 0.46% respectively.Of the people with epilepsy,39.1% were treated regularly which increased about 14% than that in the baseline survey (24.8%).The treatment gap for active epilepsy was 49.8%,which decreased by 12.8% than that in the first survey (62.6%). Conclusion The treatment gap of epilepsy in the demonstration areas has decreased remarkably,proving that the intervention measures used in the study are effective and feasible in rural areas of China.