1 Extrasynaptic GABA A receptors in the brainstem and spinal cord: structure and function. Rodolfo Delgado-Lezama 1* , Emanuel Loeza-Alcocer 1 , Carmen Andrés 1 , Justo Aguilar 1 , Pierre A. Guertin 2 Ricardo Felix 3 1 Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav-IPN), Mexico City, Mexico; 2 Department of Psychiatry and Neurosciences, Laval University, Quebec City, Canada; 3 Department of Cell Biology, Cinvestav-IPN, Mexico City, Mexico. *Author to whom all correspondence should be addressed: Dr. Rodolfo Delgado-Lezama Departamento de Fisiología, Biofísica y Neurociencias Cinvestav-IPN Avenida IPN 2508 Col. Zacatenco Mexico City, CP 07300 Mexico Email: rdelgado@fisio.cinvestav.mx Acknowledgments: E. Loeza-Alcocer and C. Andrés were supported by a fellowship from Conacyt, Mexico. The authors thank C. Arceo for her secretarial assistance. Grant sponsor: National Council of Science and Technology (Conacyt, Mexico). Keywords: Spinal cord, GABA, extrasynaptic GABAA receptors, motoneurons, primary afferent fibers.