Lesions in the pars compacta substantiae nigrae and the subthalamic nucleus modify the density of muscarinic receptors in different nuclei of the basal ganglia
INTRODUCTION Several studies that has focused to the dopaminergic transmission in the basal ganglia in parkinsonian condition, but only a few article has taking into account the imbalance between dopaminergic and cholinergic transmission. OBJECTIVE. To evaluate the muscarinic cholinergic receptors density in SNc and PPN in the 6-OHDA model.
MATERIALS AND METHODS Were organized five experimental groups in correspondence to the place of the lesion: I. Non treated rats, II. 6-OHDA lesion in SNc, III. 6-OHDA lesion in SNc + quinolinic acid lesion in NST, IV. Sham operated rats, V. Quinolinic acid in STN. Were obtained coronal sections of 20 µm thickness of SNc and PPN from rats and in these sections was evaluated the muscarinic receptors density through autoradiographic technique with [3H]quinuclidinylbenzilate (QNB) (1.23 nM). The muscarinic antagonist atropine (1 µM) was utilized as non-specific union. The density was evaluated in both hemispheres and the density optical was converted in fentomolas/mg of tissue with base to values obtained from tritium standards.
RESULTS Significant diminution of the muscarinic receptors density was found in the SNc ipsilateral to the 6-OHDA lesion from experimental groups II (t = 2.76; p < 0.05) and III (t = 4.06; p < 0.05). In the group V, was seen a significant increase of muscarinic receptor density in the SNc ipsilateral to the 6-OHDA lesion. The comparison between experimental groups evidenced significant differences among them (F = 13.13; p < 0.001) with a significant decrease in the density from SNc of groups II and III and significant increase in the density from SNc of group V in comparison of the others groups. In relation to PPN, muscarinic receptors density from right PPN ipsilateral to the 6-OHDA lesion, shown significant differences (F = 3.93; p < 0.01) between the experimental groups with a significant increase of this variable in the group II.
CONCLUSIONS These results signal a modification of cholinergic activity after 6-OHDA lesion. The changes in the muscarinic receptors populations located in SNc and PPN could be part of different compensatory mechanisms to attempt ameliorate the imbalance between dopaminergic and cholinergic transmission that it was installed after denervation of nigrostriatal forebrain bundle. The excitotoxic lesion of STN impose a new adjust mechanism for cell from PPN, which could be expressed in the changes of muscarinic cholinergic receptors population at the level of SNc.
KeywordsAutorradiographyMuscarinic receptorsPPNCategoriesInfeccionesTrastornos del movimiento
FULL TEXT(solo disponible en lengua castellana / Only available in Spanish)
Si ya es un usuario registrado en Neurologia, introduzca sus datos de inicio de sesión.
Rellene los campos para registrarse en Neurologia.com y acceder a todos nuestros artículos de forma gratuita
¿Olvidó su contraseña? Introduzca su correo electrónico y le haremos llegar una nueva
Estimado usuario de Revista de Neurología,
Debido a la reciente fusión por absorción de VIGUERA EDITORES, S.L.U., la entidad gestora de las publicaciones de Viguera Editores, entre ellas, Revista de Neurología, por EVIDENZE HEALTH ESPAÑA, S.L.U., una de las sociedades también pertenecientes al Grupo Evidenze, y con la finalidad de que Usted pueda seguir disfrutando de los contenidos y distintos boletines a los que está suscrito en la página web de neurologia.com, es imprescindible que revise la nueva política de privacidad y nos confirme la autorización de la cesión de sus datos.
Lamentamos informarle que en caso de no disponer de su consentimiento, a partir del día 28 de octubre no podrá acceder a la web de neurologia.com
Para dar su consentimiento a seguir recibiendo la revista y los boletines de neurologia.com vía correo electrónico y confirmar la aceptación de la nueva política de privacidad, así como la cesión de sus datos a Evidenze Health España S.L.U., el resto de las entidades del Grupo Evidenze y sus partners y colaboradores comerciales, incluyendo la posibilidad de llevar a cabo transferencias internacionales a colaboradores extranjeros, pulse en el siguiente enlace:
OPEN ACCESS
