Effects of acute maximal electroshock and chronic electroacupuncture on epilepsy on learning and memory in rats

[ Abstract ] Objective : To investigate the effects of acute maximal electroshock and chronic electroacupuncture on epilepsy on learning and memory in rats. METHODS : Rats were given electrical stimulation (150 mA, 0.2 s) to induce acute maximal electroshock (M ES), and chronic electroacupuncture ignited epilepsy . Rats were given a subconvulsion every 24 h via binaural clips. Dosage electrical stimulation (40 mA, 0.2 s) until complete ignition. The eight-arm maze ( four-arm bait ) was used to study the spatial learning ability and memory reproduction ability of rats. High-performance liquid chromatography (H PL C) was used to detect changes in histamine, C2 aminobutyric acid (GA BA) and glutamic acid in the brain . Results: In the learning process, compared with the control group, acute MES only increased the number of reference memory error learning process, while the BA content of rat hippocampus GA increases. In the process of spatial memory reproduction , chronic electroacupuncture ignited epilepsy increased the number of working memory and reference memory errors in rats and lasted for nearly 3 weeks after complete ignition . Chronic electroacupuncture-induced epileptic rats had degenerative changes in hippocampal CA1 neurons after 24 hours of complete igniting , and decreased hippocampal histamine content in rats. Conclusion : Different types of epilepsy have different effects on cognitive function : (1) Acute maximal electroshock impairs spatial learning ability , which may be related to abnormal synaptic plasticity and increased GA BA content in hippocampus ; (2) chronic electroacupuncture Ignition of epilepsy induced spatial memory reproducibility , which may be related to the pathological changes of hippocampal CA1 neurons and the decrease of histamine content in hippocampus.

[ Key words ] epilepsy ö pathophysiology ; memory disorder ö etiology ; reference memory ; working memory ; animal , experiment

Epilepsy is a common disease with an incidence of 0.5%. The harm caused by epilepsy is not only the seizure itself , but also

Cognitive and behavioral abnormalities such as learning and memory disorders caused by recurrent chronic epilepsy. It is generally believed that epilepsy affects cognitive function. Sa rk isian et al reported that a simple injection of alginic acid caused a sustained episode of epilepsy , which also led to severe tissue defects and memory disorders. Chronic pentylenetetrazol kindled cause histamine activity decreased, which leads to spatial memory impairment. However, awareness about epilepsy and also have different and even opposite to reports, although the impact of chronic epilepsy awareness of the formation and maintenance of varying degrees, but the effect of epilepsy on cognitive function are not all negative. For example , amygdala ignited rats showed no significant difference from the normal control group in spatial learning and social relationship experiments . Acute maximal electroshock (M ES) had no significant effect on passive avoidance response. Our previous experiments to establish a model of chronic grand mal epilepsy was kindled, and found to cause memory retention in passive avoidance reaction drop capability. This experiment intends to use the radial eight-arm maze to determine the effects of acute M ES and chronic electroacupuncture on epilepsy on spatial learning and memory in rats.

1 Materials and methods

1.1 180 animals and grouping SD rats, male, weighing 220 ~ 270g (Zhejiang University School of Medicine Laboratory Animal Center mentioned

For, clean Ê grade level, certificate number: 2229601018). Rats were randomly divided into acute M ES group, chronic electroacupuncture ignited epilepsy

Groups and control groups , each group was divided into a learning group and a memory reproduction group , with 30 rats in each group . 12 hours of light per day per dog ö12

h dark. Temperature (22 ~ 26 °C ) , humidity (40% ~ 70%), free drinking water , limit eating throughout the experiment , keep body

The weight is 80% to 85% of the free eating weight , and the behavioral experiment is arranged at 10: 00 to 17: 00 .

1. 2 acute M ES model with German HugoSach s electric stimulator (H ugoSach sT yp e221, F re ibu rg), double

Ear clip electrodes only to give a square wave pulse of 1 50H z, 150mA, 0. 2 s Stimulation generalized tonic-clonic seizures. If the hind limb tonic extension occurs (that is, with the body parallel to the extent of hindlimb extension), compared with a standard maximal electroshock (M ES).

1. 3 Chronic electroacupuncture igniting model. Rats are clipped with crocodile clips every day , and subthreshold electrical stimulation (40 mA, 0.2 s) is given.

H1 times. The control group was given crocodile clips to the ears of the rats but no current was passed. Observe behavior changes after each stimulus , and remember

Record the presence of hind limb tonic stretching (HL E) . If the animal exhibits a tonic extension of the hind limb after three consecutive electrical stimulations , then

For complete ignition. All chronic ear-illuminated rats in this experiment were completely ignited after 7 to 10 days of continuous stimulation .

1. 4 radial eight-arm maze learning acquisition and memory reproduction test as described above , radial eight-arm maze central zone diameter

30cm, extending eight arms (50cm × 12cm) to the circumference at equal angles and equal lengths . The labyrinth is 40cm above the ground . Labyrinth week

Various things are arranged as a reference. Each training, testing, eight-arm only four arms disposed prey (respectively 3, 5, 6 and 8-arm).

1. 4.1 eight-arm radial maze test procedure: rat acute or chronic transauricular M ES ignited after 24h, eight-arm radial maze start learning. Before learning to adapt to the rat in the maze two days, once a day. When adapting, 3 to 4 rats were placed in the maze at the same time , free to move and ingest bait 10m in . After the adaptation, perform one training per day . Rats were placed in the central region of the labyrinth, the central area at this time four weeks door shut, 15 s after the door is open, any rat choose to enter one arm, to take up a prey. The rat enters the arm with the bait and takes the bait for a correct choice , otherwise it is the wrong choice. Record the number of times the parameter was selected incorrectly. Re-entering the bait arm is called working memory error (w o rk ingm em o rye r ro r, WM E), and the first time entering the bait arm is called reference memory error (refe rencem em o rye r ro r, RM E ) .

1. 4.2 Memory reproducing procedure: rats reproducing method above, to perform the maze training, training 5 consecutive times the total selection error

Number 1 or 1 or less, that the training was successful. Chronic electroacupuncture and acute M ES were then given , either after fully ignited for 24 h or after acute M ES ( a few days before the control group gave the crocodile clips to the ears of the rats but no current was passed , and the last day was given M ES) for 24 h . And on the 7th , 11th , 14th , 18th , 21st , 28th , and 31st days , in the same eight-arm maze test memory reproduction process , the whole measurement process reference object and the food-feeding bait arm are consistent with the training process.

1.5 histamine and rats was measured GA BA and Glutamate M ES administration or fully kindled after 24h,

M ES group, ignition and control groups of rats were taken 6, after excess chloral hydrate anesthesia, the brains were removed, placed on a stainless steel plate (steel plate under ice), successively remove the cortex, hippocampus, storage Prepare in the -80 °C refrigerator. The brain tissue was placed with 3% perchloric acid, 5mm o löL ethanediyl tetraacetic acid sodium acetate (ED TA) 52, and a hydrogen 2N2X solution of methyl tryptamine, homogenized in an ice bath, then - setting 4 ℃ Centrifuge at 20m in (15000g) at temperature . The supernatant, with polyvinylidene fluoride film was filtered through 0. 22 Lm. High-performance liquid chromatography (H PL C) designed by our laboratory combined with electrochemical detection technology to detect histamine, GA BA and glutamic acid content in samples . The entire system consists of a 582 pump, a 542 autosampler, and a four-channel Co u lA ray electrochemical detector. The Co u lA r ray ○ R software control system was used for data collection and analysis.

1.6 Histology hippocampus in rats after administration M ES or 24h, an excess of chloral hydrate anesthesia fully kindled, irrigation from the aorta

200m l normal saline, and then 4% paraformaldehyde solution 200m l perfused, the brains immediately after the end of infusion, at room temperature at 4% paraformaldehyde solution and a 30% sucrose solution for at least 1 week. Frozen coronal slices, slice thickness 12Lm. The sections were stained with hematoxylin and eosin and mounted (H E staining ) . The morphology of pyramidal cells in the hippocampal CA1 region was observed under a microscope .

1. 7 Statistical Processing Data analysis was performed using SP SS 11. 5 fo rW indow s statistical software. The data is expressed in xq ± sxq . The comparison between groups was as homogeneous as the variance , using one-way analysis of variance and D unne t t ' s test . The variance was K ru ska l2W a llisH test and D unn ' s test.