RESUMEN
The suspension of embryonic locus coeruleus (LC) was transplanted into outbred albino rat hippocampus after its preliminary 6-hydroxy-dopamine-induced denervation. Immunohistochemical and morphometric analysis revealed that 3 months after the transplantation, embryonic noradrenergic LC cells which have completed their histogenesis in recipient hippocampus, appear as differentiated multipolar and fusiform cells, typical to LC. Intrahippocampal allotransplants of rat embryonic LC were also demonstrated to normalize the level of orientation activity in an open area, that was significantly reduced after administration of 6-hydroxy-dopamine to the animals.
Asunto(s)
Trasplante de Tejido Encefálico/métodos , Trasplante de Tejido Fetal/métodos , Hipocampo/cirugía , Locus Coeruleus/citología , Locus Coeruleus/trasplante , Neuronas/citología , Neuronas/trasplante , Análisis de Varianza , Animales , Trasplante de Tejido Encefálico/estadística & datos numéricos , Diferenciación Celular , Desnervación/métodos , Conducta Exploratoria , Trasplante de Tejido Fetal/estadística & datos numéricos , Hipocampo/citología , Hipocampo/metabolismo , Inmunohistoquímica , Locus Coeruleus/embriología , Oxidopamina , Ratas , Factores de Tiempo , Trasplante HomólogoRESUMEN
Inversion of the early component of IPSPs in neurons of the sensorimotor cortex by artificial hyperpolarization of the membrane was demonstrated in cats immobilized by myorelaxants in acute experiments. The late component of IPSP was not inverted. Amplitudes of the early component of IPSPs were decreased by the membrane depolarization while the late component was completely reduced. The input resistance of the membrane which decreased during the early component of IPSPs was restored to the initial level during the late component.
Asunto(s)
Corteza Motora/fisiología , Neuronas/fisiología , Potenciales de Acción , Animales , Gatos , Membrana Celular/fisiologíaRESUMEN
In acute experiments on immobilized cats intracellular injection of Ca+ decreased of IPSP and postburst hyperpolarization amplitudes in pyramidal neurons of the sensorimotor cortex. Intracellular injection of ethylene glycol tetraacetic acid had almost the same effect. This substance also reduced the late part of spike afterhyperpolarization, while the early part remained practically unchanged. It is concluded that Ca2+-dependent K+-conductance might play an important role in the genesis of IPSP, postburst and spike afterhyperpolarization in the membrane of pyramidal neurons of the cat sensorimotor cortex.
Asunto(s)
Calcio/fisiología , Corteza Motora/fisiología , Neuronas/fisiología , Canales de Potasio/fisiología , Tractos Piramidales/fisiología , Potenciales de Acción/efectos de los fármacos , Animales , Gatos , Cesio/farmacología , Ácido Egtácico/farmacología , Microelectrodos , Corteza Motora/efectos de los fármacos , Inhibición Neural/efectos de los fármacos , Neuronas/efectos de los fármacos , Canales de Potasio/efectos de los fármacos , Tractos Piramidales/efectos de los fármacosRESUMEN
Inversion of the early component of IPSPs in pyramidal neurons of the sensorimotor cortex by intracellular injection of chloride ions was demonstrated in cats immobilized by myorelaxants in acute experiments under moderate composed anesthesia (40 mg/kg nembutal and 20 mg/kg chloralose intraperitoneally). The late component of IPSPs as well as the post-burst hyperpolarization in pyramidal neurons were not inverted. It is concluded that during the early component of IPSPs of both pyramidal and nonpyramidal neurons the membrane permeability is increased for chloride ions, while both the late component of IPSPs and the post-burst hyperpolarization in pyramidal neurons are less dependent on the chloride permeability.