Neuroscience Letters 384 (2005) 234–238 Electroacupuncture prevents cognitive deficits in pilocarpine-epileptic rats Jair Guilherme dos Santos Jr. a , Angela Tabosa b , Fabr´ ıcio Hoffmann Martins do Monte c , Mirian Marcela Blanco a , Anafl´ avia de Oliveira Freire a , Luiz Eugˆ enio Mello a,* a Departments of Physiology and Psychobiology, Universidade Federal de S˜ ao Paulo, Rua Botucatu, 862, 5 andar, Ed. Ciˆ encias Biom´ edicas, 04023-062 S˜ ao Paulo, Brazil b Division of Chinese Medicine and Acupuncture, Department of Orthopedics and Traumatology, Universidade Federal de S˜ ao Paulo, S˜ ao Paulo, Brazil c Department of Morphophysiology, Universidade Estadual de Santa Catarina, Brazil Received 29 November 2004; received in revised form 6 April 2005; accepted 27 April 2005 Abstract Here we investigated the effects of electroacupuncture over the cognitive deficits in the pilocarpine model of epilepsy in rats. Acupuncture stimulation was provided at acupoints located in either the midline of the back and of the head [HD]: Gv-20 (Baihui), Gv-14 (Dazhui), Gv-2 (Yaoshu) and M-HN-3 (Yin Tang); or acupoints located in the limbs [LB]: St-36 (Zusanli) and Sp-6 (Sanyinjiao). In the elevated T-maze test, electroacupuncture at HD and LB acupoints produced an improvement in the acquisition and retention parameters. Retention in the inhibitory avoidance test was seen only in short-term retention and only for animals stimulated at HD. At histology it was found that electroacupuncture at HD acupoints abolished tissue shrinkage in dorsal hippocampus, basolateral nucleus of the amygdala, substantia nigra and perirhinal cortex, whereas stimulation of LB acupoints prevented tissue shrinkage in all of the above structures except dorsal hippocampus. Administration of p- chlorophenylalanine, a serotonergic releaser, abolished both behavioral and part of the histological changes in these animals. We conclude that electroacupuncture at HD and LB acupoints prevents atrophy of some limbic structures and improves cognitive deficits in pilocarpine-epileptic rats and that this effect is dependent on the serotonergic system. © 2005 Elsevier Ireland Ltd. All rights reserved. Keywords: Electroacupuncture; Temporal lobe epilepsy; Learning; Memory; Rats A number of structural abnormalities have been associated with temporal lobe epilepsy, including neuronal loss and mesial temporal sclerosis [4]. Neuronal injury, namely in hippocampus and amygdala, are likely to contribute to the cognitive deficits seen in both humans and laboratory ani- mals with temporal lobe epilepsy [18,20], given the major role of these structures in learning and memory [1,11,26]. After injury, structural changes occur in the central nervous system. This post-lesional synaptic plasticity is associated with several of the behavioral consequences that take place thereafter [9,19]. It has been suggested that electroacupuncture (EA) applied at specific acupoints increases the extracellular * Corresponding author. Tel.: +55 11 5792033; fax: +55 11 55792033. E-mail address: lemello@ecb.epm.br (L.E. Mello). serotonin levels. Serotonin is known to affect synaptic plasticity in various levels [2,24]. EA could thus affect post-lesional synaptic plasticity and cognitive deficits that ensue after pilocarpine-induced status epilepticus (SE). Pilocarpine (320 mg/kg, i.p.) SE was induced in male adult Wistar rats (for detail of the protocol see [22]). Thirty minutes after SE induction, the animals were submitted to EA proce- dures. The following experimental groups were formed: Con- trol (animals that were not injected with pilocarpine and not subjected to EA), Pilo (injected with pilocarpine and not sub- mitted to EA), Sham (injected with pilocarpine and subjected to EA at 4 non-acupoints located in close vicinity to the acu- points), HD (injected with pilocarpine and subjected to EA at Gv-20 (Baihui), Gv-14 (Dazhui), Gv-2 (Yaoshu) and M-HN- 3(Yin Tang) acupoints) and LB (injected with pilocarpine and subjected to EA at St-36 (Zusanli) and Sp-6 (Sanyinjiao) 0304-3940/$ – see front matter © 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.neulet.2005.04.079