Nicotine-induced Up-regulation and Desensitization of α4β2 Neuronal Nicotinic Receptors Depend on Subunit Ratio*

Gretchen Y. López-Hernández, Javier Sánchez-Padilla, Alejandro Ortiz-Acevedo, José Lizardi-Ortiz, Janice Salas-Vincenty, Legier V. Rojas and José A. Lasalde-Dominicci